Causes for the Formation of Titania Nanotubes
During Anodization
Xixin Wang,Jianling Zhao,Xiaohui Wang,and Ji Zhou
Abstract—Titania nanotube arrays were prepared in the electrolyte containing dimethyl sulphoxide and HF through anodization method and the morphology and composition of the nanotube arrays were characterized through scanning electron microscopy,X-ray photoelectron spectroscopy,and Auger electron spectroscopy.The causes for the formation of nanotubes have been discussed according to the experimental results.Nanopores are formed?rstly at the early stage of anodization,O2?ion needed to oxidize the titanium metal below the pore wall must diffuse inward from both sides of the pore wall.Because of the different diffusion resistances,O2?concentrations are different at different positions of the interface between titanium metal and pore wall, leading to different oxide compositions.As a result,the surface of pore wall is mainly composed of high valence oxide TiO2, while the middle of pore wall is mainly composed of suboxides, such as Ti2O3and TiO.The pore wall would crack easily at the middle low strength suboxides due to temperature changes during anodization,which results in the conversion of nanopores into nanotubes.The selective dissolution of suboxides in the electrolyte leads to the formation of gaps between nanotubes.
Index Terms—Electrochemical processes,self-organizing con-trol,semiconductor materials.
I.I NTRODUCTION
T ITANIA nanotube arrays have been successfully fabricated by anodization method in recent years[1]–[5].The nan-otube array structure may improve and enhance the performance of titania and has vast application prospects.For example,tita-nia nanotube arrays have outstanding properties in solar energy cell[6],[7],water decomposition[8],gas sensitivity[9],[10], photocatalysis[11],[12],drug delivery[13]and so forth. Compared with the large amount of literatures focusing on the preparation and properties of titania nanotube arrays,there are relatively fewer literatures on the formation mechanism of titania nanotube arrays and the traditional?eld-assistant disso-
Manuscript received September5,2013and February11,2014;accepted November7,2014.Date of publication November12,2014;date of current version January6,2015.This work was supported by National Natural Sci-ence Foundation of China(51272064),Key Basic Research Program of Hebei Province of China(No.12965135D),Natural Science Foundation of Hebei Province of China(E2013202032),the Talent Training Project of Hebei Province (2013),and the Program for Changjiang Scholars and Innovative Research Team in University.The review of this paper was arranged by Associate Editor L. Dong.(Corresponding author:J.Zhao)
X.Wang and J.Zhao(corresponding author)is with the Key Lab for Micro-and Nano-Scale Boron Nitride Materials,School of Material Science and En-gineering,Hebei University of Technology,Tianjin300130,China(e-mail: xinxinwang@https://www.doczj.com/doc/6e11078399.html,;zhaojl02@https://www.doczj.com/doc/6e11078399.html,).
X.Wang and J.Zhou is with the Department of Materials Science and En-gineering,Tsinghua University,Beijing100084,China(e-mail:wxh@mail. https://www.doczj.com/doc/6e11078399.html,;zhouji@https://www.doczj.com/doc/6e11078399.html,).
Color versions of one or more of the?gures in this paper are available online at https://www.doczj.com/doc/6e11078399.html,.
Digital Object Identi?er
10.1109/TNANO.2014.2370041Fig.1.TiO2nanotube arrays prepared in Ref.[20].
lution(FAD)theory is usually used to explain the formation of nanotubes[14]–[16].However,the existing mechanisms cannot give a comprehensive and detailed explanation to some of the experimental results.For example,the common structure char-acteristics of titania nanotube arrays prepared by anodization method include:1.nanotubes even in different tube diameters and different shapes have similar tube wall thickness;2.gaps with irregular size and shape are often formed among neigh-bouring tubes(see Fig.1)[17]–[20].All these structures cannot be explained satisfactorily only through FAD mechanism.In Fig.2,the top view of TiO2nanostructure prepared through three-step anodization[21]is of nanopore morphology and its cross-sectional view is of nanotube array structure.The gaps among the nanotubes are obviously not caused only by dissolu-tion and the true causes for the formation of nanotubes below the nanopores needs further study.
In this paper,titania nanotube arrays were prepared in the electrolyte containing dimethyl sulfoxide(DMSO)and HF.The causes for formation of titania nanotubes are discussed in de-tail according to the experimental results.This work would be helpful for the understanding of the formation process of titania nanotubes during anodization and can be used for reference to the related metal oxide nanotubes.
II.E XPERIMENTAL P ROCEDURES
The titanium foils(purity?99.6%,15×10×0.5mm3)used in this study were obtained from General Research Institute for Nonferrous Metals(Beijing,China).The foils were mechani-
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Fig.2.TiO 2nanostructure prepared in Ref.
[21].
Fig.3.
SEM images of titania layer after anodization for 7h (a)and 37h (b).
cally polished to a mirror image and washed in an ultrasonic bath of twice-distilled water and acetone before use.Electro-chemical experiments were carried out using a direct current (DC)voltage source (DH1722,Dahua Coop.,Beijing,China).Titanium foils were used as anodic electrode while platinum (20×20×0.1mm 3)was used as cathodic electrode.The dis-tance between anodic and cathodic electrodes was 20mm.The electrolyte was prepared from analytical grade chemicals and deionized water.Anodization experiments were carried out at room temperature.During the experiments,the solutions were stirred using a magnetic stirrer.After the anodization,the sam-ples were rinsed in deionized water,dried in air and char-acterized through scanning electron microscopy (SEM,JSM-6301,JEOL,Japan),X-ray photoelectron spectroscopy (XPS,AEM PHI5300,USA)and Auger electron spectroscopy (AES,PHI610,Perkin-Elmer,USA)with a 3KeV Ar ionic beam in a diameter of 1mm.The binding energy for each component is calibrated by referring to C1s (285.0eV).
III.R ESULTS AND D ISCUSSION
Fig.3shows typical SEM images of the samples anodized at 40V in DMSO containing 2wt%HF for 7and 37h.When anodization was conducted for 7h,nanopores were formed at the surface of oxide layer [see Fig.3(a)]and the insert cross-sectional image in Fig.3(a)reveals that the aligned nanotubes adhered to each other.Fig.3(b)shows that nanotube
arrays
Fig.4.The wide-scan X-ray photoelectron spectrum of as-prepared
?lm.
Fig.5.The narrow-scan X-ray photoelectron spectrum of Ti 2p (a)and O 1s
(b).
were fabricated when anodization was conducted for 37h.The experimental results show that nanopores formed initially at the surface and then converted into nanotubes during anodization.As shown in Fig.3(b),the nanotubes adhere to each other at the bottom part from point A to B;the tube diameter decreases gradually (the outer diameter is 350nm at point B and 260nm at point C as shown by the arrows)and the coarse pore wall becomes more smooth from point B to C;from point C to D,the tube wall is smooth and have no obvious change in diameter with small gaps between tubes.Similar experimental results were reported in Ref.[17].Morphological changes from point B to C may be attributed to the dissolution of the outer tube wall in electrolyte,while the unchanged tube diameter from point C to D indicates that the dissolution of tube wall at this part is very weak,otherwise,different tube diameters are unavoidable.Therefore,as concluded from the above mentioned phenomena,the initially formed tube wall must be dissolved selectively in the electrolyte.
Fig.4shows the XPS spectra of the as-prepared ?lm,in-dicating the nanotube arrays are mainly composed of Ti and O.The elements of C and F were probably introduced during anodization.Fig.5gives the narrow-scan X-ray photoelectron spectra of Ti 2p and O 1s .The asymmetric peak shape indicates that it can be divided into more than two ?tting peaks.For ex-ample,through curve ?tting,XPS spectra of Ti 2p which consist of peaks of Ti 2p 1/2and Ti 2p 3/2can be divided into three peak groups at 464.26and 458.77eV ,461.70and 457.96eV ,460.78and 457.18eV ,corresponding to TiO 2[22]–[24],Ti 2O 3[25],
W ANG et al.:CAUSES FOR THE FORMATION OF TITANIA NANOTUBES DURING ANODIZATION
115
Fig.6.AES surface analyses at the top,middle and bottom of the
nanotubes
Fig.7.AES depth pro?les of the sample (a)and in Ref.[34](b).
[26],TiO [27],[28]respectively [see Fig.5(a)].The O 1s peak in Fig.5(b)can be divided into four peaks at 529.92,530.70,531.60and 352.06eV ,corresponding to TiO 2[29]–[31],Ti 2O 3[32],TiO [32]and Ti-OH [27],respectively.Therefore,there maybe exist multiple titanium oxides in the nanotubes,where TiO 2is the main oxide and suboxides such as Ti 2O 3and TiO are in relatively lower percentage.
Studies from Petukhov et al .also veri?ed the existence of the suboxides Ti 2O 3and TiO in titania nanotubes [33].
In order to investigate the distribution of Ti and O in the oxide layer,analyses of AES were conducted and results are given in Figs.6and 7.AES results at different positions of the outer tube wall show that the relative content of O increases,the relative content of Ti decreases,and the atomic ratio of O/Ti increases correspondingly in the order of bottom,middle and top of the nanotube [see Fig.6].Know from the above discussion,the initially formed tube outer wall would be dissolved in the electrolytes and more oxides were dissolved at the top outer wall than that at the middle.Therefore,the results in Fig.6indicate that the initially formed outer tube wall possesses lower atomic ratio of O/Ti (bottom in Fig.6)and the ratio increases as the outer tube wall dissolves in the electrolytes (middle and top in Fig.6),meaning that the O/Ti atomic ratio increases from the outer to the inner for the initially formed tube wall.
The AES depth pro?les results in Fig.7(a)indicate that with the prolongation of etching time,atomic concentration of oxy-gen decreases a bit and atomic concentration of titanium in-creases slightly and the atomic ratio of O/Ti decreases gradually,which is consistent with the AES results in Fig.6.Similar result in Fig.7(b)was also reported in our earlier work [34].
Obviously,the O/Ti atomic ratio of suboxides is lower than that of high valence oxide,hence,according to the above
ex-
Fig.8.Formation process of titania nanotubes.(a)Initially formed nanopores.(b)Structures of the pore wall.(c)Temperature distribution of the oxide layer.(d)Formation of the gaps between nanotubes.
perimental and analytical results,the initially formed outer tube wall was mainly composed of suboxides (e.g.,Ti 2O 3and TiO)and the inner tube wall was mainly composed of high valence oxides (TiO 2).The selective dissolution in the electrolyte of initially formed tube wall [see Fig.3(b)]might be attributed to the different compositions of inner and outer tube wall.The formation process of titania nanotubes can be depicted as Fig.8.During anodization,nanopores are formed initially at the sur-face of titanium metal.The initially formed nanopore wall is composed of high valence oxide (TiO 2)because Ti is directly contacted with the electrolyte which provides suf?cient O 2?.Af-ter that,the O 2?needed to oxidize the Ti metal below the pore wall must be diffused inward through both sides of the pore wall [see Fig.8(a)].As shown in Fig.8(b),due to the in?uences of diffusion resistance,the O 2?concentrations are different at dif-ferent positions of the interface between the Ti metal and pore wall.Higher O 2?concentration at interface from A to B results in the formation of high valence oxide (TiO 2)(equation (1))and lower O 2?concentrations at interface B-C and C-D result in the formation of suboxides (e.g.,Ti 2O 3and TiO)(equations (2)and (3)).Along with the extension of anodization time,the reaction interface move downward and these oxides constitute the newly formed pore wall,with high valence oxide constituting the sur-face layer and suboxides constituting middle part of the newly formed pore wall.
Ti +2O 2?(suf?cient )=TiO 2+4e ?(1)2Ti +3O 2?(insuf?cient )=Ti 2O 3+6e ?
(2)Ti +O 2?(insuf?cient)=TiO +2e ?.
(3)
In high valence oxide,Ti 4+ions bond with four O ions;in low valence oxide,Ti ions bond with fewer O ions (two,for exam-ple).Therefore,high valence oxide would form a higher strength crosslinking network structure which is hard to be dissolved in the electrolyte and suboxides would form a lower strength struc-ture which is easy to be dissolved in the electrolyte.Therefore,the pore wall structure characteristics in Fig.8(b)might very well lead to crack in the middle suboxides part and result in the formation of the morphology in Fig.3.
When titanium is anodized,the evolution of considerable heat (ΔH =?944kJ ·mol ?1[35])causes the rising temperature at
116IEEE TRANSACTIONS ON NANOTECHNOLOGY,VOL.14,NO.1,JANUARY2015
the reaction interface[see Fig.8(c)].Along with the extension of anodization,the reaction interface moves downward and the temperature of pore wall formed at higher temperature decreases and the pore wall contracts accordingly.As discussed above,the middle part of pore wall is mainly composed of suboxides which is in low structural strength,therefore the contraction of adjacent pore wall would lead to cracking of suboxides at the middle part of pore wall.In addition,the interface reaction rates on both sides of point D in Fig.8(b)would not be identical entirely and different reaction rates would result in the non-uniform longitudinal expansion and the formation of cracks in the middle part of pore wall.When the pore wall cracks at the middle part, nanopores would convert into nanotubes accordingly[36]. During anodization,the initially formed pore wall(i.e.,initial pore wall in Fig.8(b))can be dissolved slowly in the electrolyte. And then,the suboxides at the middle part of pore wall[see Fig.8(b),B-D]would be dissolved selectively in the electrolyte and lead to the formation of the nanotube structure as shown in Fig.8(d)because suboxides are easier to be dissolved than high valence oxide[35].
TiO2nanostructure as shown in Fig.2would be obtained when the initially formed TiO2pore wall cannot crack due to contraction and cannot be dissolved in the electrolyte either. The thickness of surface TiO2layer of pore wall[see Fig.8(b), A-B]is affected by the transfer speed O2?ions.Under de?nite reaction conditions,there are similar transfer speed of O2?and similar TiO2thickness at the surface of pore wall,therefore,the formed nanotubes are all in similar wall thickness.The irregular gaps between nanotubes in Fig.1are formed after dissolution of suboxides.
IV.C ONCLUSION
At the beginning of anodization,nanopores are formed at the surface of titanium metal and the initially formed pore wall are composed of high valence oxide(TiO2).After the formation of nanopores,the O2?needed to oxidize the Ti metal below the pore wall must be diffused inward through both sides of the pore wall. Due to the in?uences of diffusion resistance,O2?concentrations are different at different interface positions between Ti metal and pore wall,leading to different oxide compositions.Higher O2?concentration results in the formation of high valence oxide and lower O2-concentrations result in the formation of suboxides (e.g.,Ti2O3and TiO).Along with the extension of anodization time,the reaction interface moves downward and these oxides constitute the newly formed pore wall,with high valence oxide constituting the surface layer and suboxides constituting middle part of the newly formed pore wall.
When titanium is anodized,the temperature is higher at the reaction interface.Along with the extension of anodization, the reaction interface moves downward and the temperature of pore wall formed at higher temperature decreases and the pore wall contracts accordingly.The contraction of adjacent pore wall would lead to cracking of suboxides at the middle part of pore wall and result in the conversion of nanopores into nanotubes. The high valence oxide with crosslinking network are dif?-cult to be dissolved in the electrolyte while suboxides without crosslinking network are easy to be dissolved.Therefore,dur-ing anodization,the suboxides at the middle pore wall(or outer tube wall)would be dissolved selectively in the electrolyte and lead to the formation of gaps between nanotubes.Under de?-nite reaction conditions,there are similar transfer speed of O2?and similar thickness of the high valence oxide at the surface of pore wall,therefore,the formed nanotubes are all in similar wall thickness.
R EFERENCES
[1]W.Chanmanee,A.Watcharenwong,C.R.Chenthamarakshan,P.Ka-
jitvichyanukul,N.R.Tacconi,and K.Rajeshwar,“Titania nanotubes from pulse anodization of titanium foils,”https://www.doczj.com/doc/6e11078399.html,mun.,vol.9,pp.
2145–2149,2007.
[2]S.Yoriya,“Effect of inter-electrode spacing on electrolyte properties and
morphologies of anodic TiO2nanotube array?lms,”Int.J.Electrochem.
Sci.,vol.7,pp.9454–9464,2012.
[3]J.M.Macak,H.Tsuchiya,L.Taveira,S.Aldabergerova,and P.Schmuki,
“Smooth anodic TiO2nanotubes,”Angewandte Chemie Int.Edition,vol.
44,pp.7463–7465,2005.
[4]J.Zhao,X.Wang,T.Sun,and L.Li,“In situ templated synthesis of anatase
single-crystal nanotube arrays,”Nanotechnology,vol.16,pp.2450–2454, 2005.
[5]H.Li,J.Wang,K.Huang,G.Sun,and M.Zhou,“In-situ preparation of
multi-layer TiO2nanotube array thin?lms by anodic oxidation method,”
Mater.Lett.,vol.65,pp.1188–1190,2011.
[6]G.K.Mor,K.Shankar,M.Paulose,O.K.Varghese,and C.A.Grimes,“Use
of highly-ordered TiO2nanotube arrays in dye-sensitized solar cells,”
Nano Lett.,vol.6,pp.215–218,2006.
[7]J.Zhao,X.Wang,Y.Kang,X.Xu,and Y.Li,“Photoelectrochemical
activities of W-doped titania nanotube arrays fabricated by anodization,”
Photon.Technol.Lett.,vol.20,pp.1213–1215,2008.
[8]J.H.Park,S.Kim,and A.J.Bard,“Novel carbon-doped TiO2nanotube
arrays with high aspect ratios for ef?cient solar water splitting,”Nano Lett.,vol.6,pp.24–28,2006.
[9]S.Lin,D.Li,J.Wu,X.Li,and S.Akbar,“A selective room temperature
formaldehyde gas sensor using TiO2nanotube arrays,”Sensors Actuators B:Chemical,vol.156,pp.505–509,2011.
[10]H.F.Lu,F.Li,G.Liu,A.G.Chen,D.W.Wang,H.T.Fang,G.Q.Lu,
Z.H.Jiang,and H.M.Cheng,“Amorphous TiO2nanotube arrays for low-temperature oxygen sensors,”Nanotechnology,vol.19,Article ID: 405504,pp.1–7,2008.
[11]P.Roy,S.Berger,and P.Schmuki,“TiO2nanotubes:Synthesis and appli-
cations,”Angewandte Chemie Int.Edition,vol.50,pp.2904–2939,2011.
[12] C.Ruan,M.Paulose,O.K.Varghese,and C.A.Grimes,“Enhanced
photoelectrochemical-response in highly ordered TiO2nanotube-arrays anodized in boric acid containing electrolyte,”Sol.Energy Mater.Sol.
Cells,vol.90,pp.1283–1295,2006.
[13]M.S.Aw et al.,“A multi-drug delivery system with sequential release
using titania nanotube arrays,”https://www.doczj.com/doc/6e11078399.html,mun.,vol.48,pp.3348–3350, 2012.
[14]G.K.Mor,O.K.Varghese,M.Paulose,K.Shankar,and C.A.Grimes,“A
review on highly ordered,vertically oriented TiO2nanotube arrays:Fab-rication,material properties,and solar energy applications,”Sol.Energy Mater.Sol.Cells,vol.90,pp.2011–2075,2006.
[15]S.V.Kuchibhatla,A.Karakoti,D.Bera D,and S.Seal,“One dimensional
nanostructured materials,”Progress Mater.Sci.,vol.52,pp.699–913, 2007.
[16]H.Li,M.Liu,H.Wang,J.Wu,P.Su,D.Li,and J.Wang,“Formation
process of tio2nanotube arrays prepared by anodic oxidation method,”J.
Nanosci.Nanotechnol.,vol.13,pp.4110–4116,2013.
[17]M.Paulose,K.Shankar,S.Yoriya,H.E.Prakasam,O.K.Varghese,G.K.
Mor,https://www.doczj.com/doc/6e11078399.html,tempa,A.Fitzgerald,and C.A.Grimes,“Anodic growth of highly ordered TiO2nanotube arrays to134μm in length,”The J.Phys.
Chem.B,vol.110,pp.16179–16184,2006.
[18]S.Mohapatra,M.Misra,V.Mahajan,and K.Raja,“A novel method for
the synthesis of titania nanotubes using sonoelectrochemical method and its application for photoelectrochemical splitting of water,”J.Catalysis, vol.246,pp.362–369,2007.
[19]V.Prida,E.Manova,V.Vega,M.Hernandez-Velez,P.Aranda,K.Pirota,
M.V′a zquez,and E.Ruiz-Hitzky,“Temperature in?uence on the anodic growth of self-aligned Titanium dioxide nanotube arrays,”J.Magn.Magn.
Mater.,vol.316,pp.110–113,2007.
W ANG et al.:CAUSES FOR THE FORMATION OF TITANIA NANOTUBES DURING ANODIZATION117
[20]N.Wang,X.Li,Y.Wang,X.Quan,and G.Chen,“Evaluation of bias po-
tential enhanced photocatalytic degradation of4-chlorophenol with TiO2 nanotube fabricated by anodic oxidation method,”Chem.Eng.J.,vol.146, pp.30–35,2009.
[21]G.Zhang,H.Huang,Y.Zhang,H.L.Chan,and L.Zhou,“Highly or-
dered nanoporous TiO2and its photocatalytic properties,”Electrochem.
Commun.,vol.9,pp.2854–2858,2007.
[22]W.E.Slink and P.B.DeGroot,“Vanadium-titanium oxide catalysts for
oxidation of butene to acetic acid,”J.Catalysis,vol.68,pp.423–432, 1981.
[23]J.Fierro,L.Arrua,N.J.Lopez,and G.Kremenic,“Surface properties of
Co-precipitated VTiO catalysts and their relation to the selectiveoxidation of isobutene,”Appl.Catalysis,vol.37,pp.323–338,1988.
[24]I.Georgiadou,N.Spanos,C.Papadopoulou,H.Matralis,C.Kordulis,
and A.Lycourghiotis,“Preparation and characterization of various ti-tanias(anatase)used as supports for vanadia-supported catalysts,”Col-loids Surfaces A:Physicochem.Eng.Aspects,vol.98,pp.155–165, 1995.
[25] F.Werfel and O.Br¨u mmer,“Corundum structure oxides studied by XPS,”
Physica Scripta,vol.28,pp.92–96,1983.
[26] D.Gonbeau,C.Guimon,G.P?ster-Guillouzo,A.Levasseur,G.Meunier,
and R.Dormoy,“XPS study of thin?lms of titanium oxysul?des,”Surface Sci.,vol.254,pp.81–89,1991.
[27] E.McCafferty and J.Wightman,“An X-ray photoelectron spectroscopy
sputter pro?le study of the native air-formed oxide?lm on titanium,”Appl.
Surface Sci.,vol.143,pp.92–100,1999.
[28]T.Tan,S.Wang,S.Bian,X.Li,Y.An,and Z.Liu,“Novel synthesis and
electrophoretic response of low density TiO–TiO2–carbon black compos-ite,”Appl Surface Sci.,vol.256,pp.6932–6935,2010.
[29]https://www.doczj.com/doc/6e11078399.html,ter?eld,P.Martin,C.Pacey,W.Sainty,D.McKenzie,and G.
Auchterlonie,“Ion-assisted deposition of mixed TiO2-SiO2?lms,”J.
Appl.Phys.,vol.66,pp.1805–1809,1989.[30]R.Sanjines,H.Tang,H.Berger,F.Gozzo,G.Margaritondo,and F.Levy,
“Electronic structure of anatase TiO2oxide,”J.Appl.Phys.,vol.75,pp.
2945–2951,1994.
[31] C.Sleigh,A.Pijpers,A.Jaspers,B.Coussens,and R.J.Meier,“On
the determination of atomic charge via ESCA including application to organometallics,”J.Electron Spectroscopy Related Phenomena,vol.77, pp.41–57,1996.
[32]J.Yao,J.Shao,H.He,and Z.Fan,“Optical and electrical properties of
TiOx thin?lms deposited by electron beam evaporation,”Vacuum,vol.
81,pp.1023–1028,2007.
[33] D.I.Petukhov,A.A.Eliseev,I.V.Kolesnik,K.S.Napolskii,A.V.
Lukashin,Y.D.Tretyakov,S.V.Grigoriev,N.V.Grigorieva,and H.
Eckerlebe,“Formation mechanism and packing options in tubular anodic titania?lms,”Microporous Mesoporous Mater.,vol.114,pp.440–447, 2008.
[34]J.Zhao,X.Wang,and L.Li,“Electrochemical fabrication of well-ordered
titania nanotubes in H3PO4/HF electrolytes,“Electron.Lett.,vol.41,pp.
771–772,2005
[35]J.Speight,16th ed.,Lange’s Handbook of Chemistry,Laramie,Wyoming,
USA:CD&W Inc,2004.
[36]X.Wang,J.Zhao,X.Wang,and J.Zhou,“In?uence of mass and heat
transfer on morphologies of metal oxide nanochannel arrays prepared by anodization method,”ISRN Nanotechnol.,vol.2011,Article ID:480970, pp.1–5,2011.
Authors’photographs and biographies not available at the time of publication.
of与for的用法以及区别 for 表原因、目的 of 表从属关系 介词of的用法 （1）所有关系 this is a picture of a classroom （2）部分关系 a piece of paper a cup of tea a glass of water a bottle of milk what kind of football，American of soccer？ （3）描写关系 a man of thirty 三十岁的人 a man of shanghai 上海人 （4）承受动作 the exploitation of man by man．人对人的剥削。 （5）同位关系 It was a cold spring morning in the city of London in England． （6）关于，对于 What do you think of Chinese food？ 你觉得中国食品怎么样？ 介词 for 的用法小结 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。What will we have for supper? 我们晚餐吃什么?
2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。
to与for的用法和区别 一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb.表示对某人有直接影响比如，食物对某人好或者不好就用to; for表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语？ 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．对于 1．She has a liking for painting. 她爱好绘画。 2．She had a natural gift for teaching. 她对教学有天赋/ 3．表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法？ 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于（常有较活译法） 1 Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，对于（某人），对…来说（多和形容词连用）用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。 6．for和fit, good, bad, useful, suitable 等形容词连用，表示适宜，适合。 Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 Exercises are good for health. 锻炼有益于健康。 Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 You are not suited for the kind of work you are doing. 7. for表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 1．It would be best for you to write to him. 2．The simple thing is for him to resign at once. 3．There was nowhere else for me to go. 4．He opened a door and stood aside for her to pass.
For的用法 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。 尽管for 的用法较多，但记住常用的几个就可以了。 to的用法: 一：表示相对，针对 be strange (common, new, familiar, peculiar) to This injection will make you immune to infection. 二：表示对比，比较 1：以-ior结尾的形容词，后接介词to表示比较，如：superior ,inferior,prior,senior,junior 2: 一些本身就含有比较或比拟意思的形容词，如equal，similar，equivalent，analogous A is similar to B in many ways.
介词for用法归纳 用法1：(表目的)为了。如： They went out for a walk. 他们出去散步了。 What did you do that for? 你干吗这样做？ That’s what we’re here for. 这正是我们来的目的。 What’s she gone for this time? 她这次去干什么去了？ He was waiting for the bus. 他在等公共汽车。 【用法说明】在通常情况下，英语不用for doing sth 来表示目的。如： 他去那儿看他叔叔。 误：He went there for seeing his uncle. 正：He went there to see his uncle. 但是，若一个动名词已名词化，则可与for 连用表目的。如： He went there for swimming. 他去那儿游泳。(swimming 已名词化) 注意：若不是表目的，而是表原因、用途等，则其后可接动名词。(见下面的有关用法) 用法2：(表利益)为，为了。如： What can I do for you? 你想要我什么？ We study hard for our motherland. 我们为祖国努力学习。 Would you please carry this for me? 请你替我提这个东西好吗？ Do more exercise for the good of your health. 为了健康你要多运动。 【用法说明】(1) 有些后接双宾语的动词(如buy, choose, cook, fetch, find, get, order, prepare, sing, spare 等)，当双宾语易位时，通常用for 来引出间接宾语，表示间接宾语为受益者。如： She made her daughter a dress. / She made a dress for her daughter. 她为她女儿做了件连衣裙。 He cooked us some potatoes. / He cooked some potatoes for us. 他为我们煮了些土豆。 注意，类似下面这样的句子必须用for： He bought a new chair for the office. 他为办公室买了张新办公椅。 (2) 注意不要按汉语字面意思，在一些及物动词后误加介词for： 他们决定在电视上为他们的新产品打广告。 误：They decided to advertise for their new product on TV. 正：They decided to advertise their new product on TV. 注：advertise 可用作及物或不及物动词，但含义不同：advertise sth＝为卖出某物而打广告；advertise for sth＝为寻找某物而打广告。如：advertise for a job=登广告求职。由于受汉语“为”的影响，而此处误加了介词for。类似地，汉语中的“为人民服务”，说成英语是serve the people，而不是serve for the people，“为某人的死报仇”，说成英语是avenge sb’s death，而不是avenge for sb’s death，等等。用法3：(表用途)用于，用来。如： Knives are used for cutting things. 小刀是用来切东西的。 This knife is for cutting bread. 这把小刀是用于切面包的。 It’s a machine for slicing bread. 这是切面包的机器。 The doctor gave her some medicine for her cold. 医生给了她一些感冒药。 用法4：为得到，为拿到，为取得。如： He went home for his book. 他回家拿书。 He went to his friend for advice. 他去向朋友请教。 She often asked her parents for money. 她经常向父母要钱。
of 1....的,属于 One of the legs of the table is broken. 桌子的一条腿坏了。 Mr.Brown is a friend of mine. 布朗先生是我的朋友。 2.用...做成的;由...制成 The house is of stone. 这房子是石建的。 3.含有...的;装有...的 4....之中的;...的成员 Of all the students in this class,Tom is the best. 在这个班级中,汤姆是最优秀的。 5.(表示同位) He came to New York at the age of ten. 他在十岁时来到纽约。 6.(表示宾格关系) He gave a lecture on the use of solar energy. 他就太阳能的利用作了一场讲演。 7.(表示主格关系) We waited for the arrival of the next bus. 我们等待下一班汽车的到来。
I have the complete works of Shakespeare. 我有莎士比亚全集。 8.来自...的;出自 He was a graduate of the University of Hawaii. 他是夏威夷大学的毕业生。 9.因为 Her son died of hepatitis. 她儿子因患肝炎而死。 10.在...方面 My aunt is hard of hearing. 我姑妈耳朵有点聋。 11.【美】(时间)在...之前 12.(表示具有某种性质) It is a matter of importance. 这是一件重要的事。 For 1.为,为了 They fought for national independence. 他们为民族独立而战。 This letter is for you. 这是你的信。
1.两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for：(1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如：do sb a favour＝do a favour for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害
for的用法： 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如:
I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如:
1.表示各种“目的”，用for （1）What do you study English for 你为什么要学英语？ （2）went to france for holiday. 她到法国度假去了。 （3）These books are written for pupils. 这些书是为学生些的。 （4）hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．“对于”用for （1）She has a liking for painting. 她爱好绘画。 （2）She had a natural gift for teaching. 她对教学有天赋/ 3．表示“赞成、同情”，用for （1）Are you for the idea or against it 你是支持还是反对这个想法？ （2）He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 （3）I felt deeply sorry for my friend who was very ill. 4. 表示“因为，由于”（常有较活译法），用for （1）Thank you for coming. 谢谢你来。
（2）France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，“对于（某人），对…来说”，（多和形容词连用），用介词to，不用for. （1）He said that money was not important to him. 他说钱对他并不重要。 （2）To her it was rather unusual. 对她来说这是相当不寻常的。 （3）They are cruel to animals. 他们对动物很残忍。 6．和fit, good, bad, useful, suitable 等形容词连用，表示“适宜，适合”，用for。（1）Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 （2）Exercises are good for health. 锻炼有益于健康。 （3）Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 （4）You are not suited for the kind of work you are doing. 7. 表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 （1）It would be best for you to write to him. （2） The simple thing is for him to resign at once.
常用介词用法(for-to-with-of)
For的用法 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。
5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。
加入收藏夹 主题： 介词试题It’s + 形容词 + of sb. to do sth.和It’s + 形容词 + for sb. to do sth.的用法区别。 内容： It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 提交人：杨天若时间：1/23/2008 20:5:54 主题：for 与of 的辨别 内容：It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 答：选A 解析：该题考查的句型It’s + 形容词+ of sb. to do sth.和It’s +形容词+ for sb. to do sth.的用法区别。 “It’s + 形容词+ to do sth.”中常用of或for引出不定式的行为者，究竟用of sb.还是用for sb.，取决于前面的形容词。 1) 若形容词是描述不定式行为者的性格、品质的，如kind，good，nice，right，wrong，clever，careless，polite，foolish等，用of sb. 例： It’s very kind of you to help me. 你能帮我，真好。 It’s clever of you to work out the maths problem. 你真聪明，解出了这道数学题。 2) 若形容词仅仅是描述事物，不是对不定式行为者的品格进行评价，用for sb.，这类形容词有difficult，easy，hard，important，dangerous，（im）possible等。例： It’s very dangerous for children to cross the busy street. 对孩子们来说，穿过繁忙的街道很危险。 It’s difficult for u s to finish the work. 对我们来说，完成这项工作很困难。 for 与of 的辨别方法： 用介词后面的代词作主语，用介词前边的形容词作表语，造个句子。如果道理上通顺用of，不通则用for. 如： You are nice.(通顺，所以应用of)。 He is hard.(人是困难的，不通，因此应用for.) 由此可知，该题的正确答案应该为A项。 提交人：f7_liyf 时间：1/24/2008 11:18:42
1. 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for： (1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。 如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如： do sb a favou r do a favour for sb 帮某人的忙 do sb harnn= do harm to sb 对某人有害
to和for的用法有什么不同（一） 一、引出间接宾语时的区别 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for，具体应注意以下三种情况： 1. 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。如： 请把那本字典递给我。 正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。 正：She taught us music last year. 正：She taught music to us last year. 2. 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose, prepare, spare 等之后用介词for 。如： 他为我们唱了首英语歌。 正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。 正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes?
正：Can you spare a few minutes for me? 3. 有的动词由于用法和含义不同，用介词to 或for 都是可能的。如： do sb a favor＝do a favor for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害 在有的情况下，可能既不用for 也不用to，而用其他的介词。如： play sb a trick＝play a trick on sb 作弄某人 请比较： play sb some folk songs＝play some folk songs for sb 给某人演奏民歌 有时同一个动词，由于用法不同，所搭配的介词也可能不同，如leave sbsth 这一结构，若表示一般意义的为某人留下某物，则用介词for 引出间接宾语，即说leave sth for sb；若表示某人死后遗留下某物，则用介词to 引出间接宾语，即说leave sth to sb。如： Would you like to leave him a message? / Would you like to leave a message for him? 你要不要给他留个话？ Her father left her a large fortune. / Her father left a large fortune to her. 她父亲死后给她留下了一大笔财产。 二、表示目标或方向的区别 两者均可表示目标、目的地、方向等，此时也要根据不同动词分别对待。如： 1. 在come, go, walk, move, fly, ride, drive, march, return 等动词之后通常用介词to 表示目标或目的地。如： He has gone to Shanghai. 他到上海去了。 They walked to a river. 他们走到一条河边。
keep的用法 1. 用作及物动词 ①意为"保存；保留；保持；保守"。如： Could you keep these letters for me, please? 你能替我保存这些信吗？ ②意为"遵守；维护"。如： Everyone must keep the rules. 人人必须遵守规章制度。 The teacher is keeping order in class.老师正在课堂上维持秩序。 ③意为"使……保持某种(状态、位置或动作等)"。这时要在keep的宾语后接补足语，构 成复合宾语。其中宾语补足语通常由形容词、副词、介词短语、现在分词和过去分词等充当。如： 例：We should keep our classroom clean and tidy.(形容词) 我们应保持教室整洁干净。 You'd better keep the child away from the fire.(副词)你最好让孩子离火远一点。 The bad weather keeps us inside the house.(介词短语)坏天气使我们不能出门。 Don't keep me waiting for long.(现在分词)别让我等太久。 The other students in the class keep their eyes closed.(过去分词) 班上其他同学都闭着眼睛。 2. 用作连系动词 构成系表结构：keep＋表语，意为"保持，继续(处于某种状态)"。其中表语可用形容词、副词、介词短语等充当。如： 例：You must look after yourself and keep healthy.(形容词) 你必须照顾好自己，保持身体健康。 Keep off the grass.(副词)请勿践踏草地。 Traffic in Britain keeps to the left.(介词短语)英国的交通是靠左边行驶的。 注意：一般情况下，keep后接形容词较为多见。再如： She knew she must keep calm.她知道她必须保持镇静。 Please keep silent in class.课堂上请保持安静。 3. ①keep doing sth. 意为"继续干某事"，表示不间断地持续干某事，keep后不 能接不定式或表示静止状态的v-ing形式，而必须接延续性的动词。 例：He kept working all day, because he wanted to finish the work on time. 他整天都在不停地工作，因为他想准时完成工作。 Keep passing the ball to each other, and you'll be OK.坚持互相传球，你们就
202X中考英语：to和for的区别与用法中考栏目我为考生们整理了“202X中考英语：to和for的区别与用法”，希望能帮到大家，想了解更多考试资讯，本网站的及时更新哦。 202X中考英语：to和for的区别与用法 to和for的区别与用法是什么 一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb. 表示对某人有直接影响比如，食物对某人好或者不好就用to; for 表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语? 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。
2.对于 1.She has a liking for painting. 她爱好绘画。 2.She had a natural gift for teaching. 她对教学有天赋。 3.表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法? 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于(常有较活译法) 1.Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5.当事人对某事的主观看法，对于(某人)，对?来说(多和形容词连用)用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。
to , of 和for的区别 1.to有到的意思，常常和go，come，get连用引出地点。Go to school , go to the shop , go to the cinema. 常见的短语：the way to 去---的路 On one’s way to 在某人去---的路上 以上的用法中，当地点是副词home，here，there等是to 要去掉。如：get home，the way here To后跟动词原形，是不定式的标志 It is +形容词+(for/of +人+)to do sth.(括号内部分可以省略) It is easy for me to learn English. It is very kind of you to lend me your money. 当形容词表示人的行为特征时用of表示to do的性质时用for Want, hope ,decide, plan , try , fail等词后跟to do I want to join the swimming club. Would like to do I’d like to play basketball with them. It is time to have a break. Next to , close to , from ---to--- 2.for 为，表示目的。 Thank you for Buy sth for sb =buy sb sth It is time for bed. Here is a letter for you.
I will study for our country. 3.of表示所属关系意思是：---的 a map of the world a friend of mine
for和of引导的不定式结构的区别 不定式是一种非谓语动词，不能单独作谓语，因此没有语法上的主语。但由于不定式表示的是动作，在意义上可以有它的主体。我们称之为逻辑主语。 提起不定式逻辑主语，人们首先想到的会是“for+名词（宾格代词）+不定式”的复合结构。如：It is important for us to study English well．然而，有时不定式的逻辑主语须要用“of+名词（代词宾格）”才行。例如：It is kind of you to help me．而不能说：It is kind for you to help me．在选择介词“for”还是“of”时，人们往往总是凭感觉而定。有时受习惯影响，多选介词“for”。于是常出现这样的错误：It was careless for him to lose his way．It is cruel for you to do so．由于众多语法书对这种结构中使用“for”与“of”的区别介绍甚少，一些人对其概念认识尚不完全清楚，笔者认为有必要就这一问题作些探讨与介绍。 一、在句中的语法作用不同 a．不定式for结构在句中可以作主、宾、表、定、状、同位语： 1．It is easy for Tom to do this work．（主语）汤姆做此工作是容易的。 2．I'd like for him to come here．（宾语）我喜欢他来这里。 3．His idea is for us to travel in two different groups．（表语）他的想法是：我们分成两组旅行。 4．Have you heard about the plan for you to go abroad．（定语）你听到让你出国的计划吗？ 5．The word is too difficult for him to pronounce well．（状语）这单词太难，他念不准。 6．In the most schools，it is the custom for the headmaster to declare the newterm start．在大部分学校，校长宣布新学期开始是一个习惯。 b．不定式of结构只能在句中作主语。 1．It was careless of him to leave his umbrella in the train．他把伞丢在火车上真是太粗心了。 2．It is awfully good of you to come to see me off at the station．谢谢你来车站送我。 二、逻辑主语的名词有所不同