摘要
溶胶-凝胶法制备5at.%V掺杂的TiO2和纯TiO2,然后在500℃煅烧6h。XRD谱图显示,样品均是锐钛矿型TiO2,还有一些无定型成分,平均晶粒大小分别为6.8nm和9.7nm。TEM照片显示的纳米粒子大小分别在8.0~18.7nm和21.6~30.2nm范围内,比XRD计算结果大,这是因为样品未能充分分散所造成。EDS谱图显示V的掺杂量是6.5at.%,红外光谱也证实V元素的存在。拉曼光谱表明,V元素均匀地分散在TiO2中。Rh.B的光催化降解实验表明,V掺杂TiO2的光催化效率比纯TiO2低,这是由于较高的掺杂浓度导致电子-空穴复合中心增加,从而降低光催化效率。
5at.% V doped TiO2 and pure TiO2 nanoparticles were synthesized throug the sol-gel method and calcined at 500 ℃ for 6 h.XRD pattens showed that both samples were anatase TiO2 with some amorphous and crystal sizes were 6.8 nm and 9.7 nm,respectively.TEM images showed that nanoparticle sizes were in the ranges of 8.0 ~ 18.7nm and 21.6 ~ 30.2 nm for V doped TiO2 and pure TiO2,respectively,larger than the values calculated from the XRD patterns,due to the poor dispersion of TiO2 samples.EDS measurement confirmed the presence of V elements with a6.5at.%,also supported by IR spectrum.Raman spectrum confirmed the well dispersions of V elements in the TiO2 matrix.The photodegradation of Rh.B showed that the photodegradation efficiency of V doped TiO2 was lower than that of pure TiO2,probably due to the enhancement of electron-hole pair recombination rate resulted from the high doping level.
引文
[1]Hongmin Wu,Jinzhu Ma,Yaobin Li,et al.Photocatalytic oxidation of gaseous ammonia over fluorinated Ti O2with exposed(001)facets[J].Applied Catalysis B:Environmental,2014,152-153:82-87.
[2]Swagata Banerjee,Suresh C.Pillai,Polycarpos Falaras,et al.New Insights into the Mechanism of Visible Light Photocatalysis[J].J.Phys.Chem.Lett.,2014,5:2543-2554.
[3]Varun Sivaram,Edward J.W.Crossland,Tomas Leijtens,et al.Observation of Annealing-Induced Doping in Ti O2Mesoporous Single Crystals for Use in Solid State Dye Sensitized Solar Cells[J].J.Phys.Chem.C,2014,118:1821-1827.
[4]Hui-Seon Kim,Nam-Gyu Park.Parameters Affecting I-V Hysteresis of CH3NH3Pb I3Perovskite Solar Cells-Effects of Perovskite Crystal Size and Mesoporous Ti O2Layer[J].J.Phys.Chem.Lett.,2014,5:2927-2934.
[5]Hui Xiong,Michael D.Slater,Mahalingam Balasubramanian,et al.Amorphous Ti O2Nanotube Anode for Rechargeable Sodium Ion Batteries[J].J.Phys.Chem.Lett.,2011,2:2560-2565.
[6]Shaohua Liu,Haiping Jia,Lu Han,et al.Nanosheet-Constructed Porous Ti O2-B for Advanced Lithium Ion Batteries[J].Adv.Mater.,2012,24:3201-3204.
[7]J.Arbiol,J.Cerdà,G.Dezanneau,et al.Effects of Nb doping on the Ti O2anatase-to-rutile phase transition[J].J.Appl.Phys.,2002,92:853-861.
[8]Rajnish K.Sharma,M.C.Bhatnagar.Improvement of the oxygen gas sensitivity in doped Ti O2thick films[J].Sensors and Actuators B,1999,56:216-219.
[9]Ewa Adamek,Wojciech Baran,Justyna Ziemiańska,et al.Effect of Fe Cl3on sulfonamide removal and reduction of antimicrobial activity of wastewater in a photocatalytic process with Ti O2[J].Applied Catalysis B:Environmental,2012,126:29-38.
[10]Sean Carbonaro,Matthew N.Sugihara,Timothy J.Strathmann.Continuous-flow photocatalytic treatment of pharmaceutical micropollutants:Activity,inhibition,and deactivation of Ti O2photocatalysts in wastewater effluent[J].Applied Catalysis B:Environmental,2013,129:1-12.
[11]Gulin Selda Pozan,Ayca Kambur.Removal of 4-chlorophenol from wastewater:Preparation,characterization and photocatalytic activity of alkaline earth oxide doped Ti O2[J].Applied Catalysis B:Environmental,2013,129:409-415.
[12]Yean Ling Pang,Ahmad Zuhairi Abdullah.Fe3+doped Ti O2nanotubes for combined adsorption-sonocatalytic degradation of real textile wastewater[J].Applied Catalysis B:Environmental,2013,129:473-481.
[13]Liqiang Jing,Baifu Xin,Fulong Yuan,et al.Effects of Surface Oxygen Vacancies on Photophysical and Photochemical Processes of Zn-Doped Ti O2Nanoparticles and Their Relationships[J].J.Phys.Chem.B,2006,110:17860-17865.
[14]Haimei Liu,Akihito Imanishi,Yoshihiro Nakato.Mechanisms for Photooxidation Reactions of Water and Organic Compoundson CarbonDoped Titanium Dioxide,as Studied by Photocurrent Measurements[J].J.Phys.Chem.B,2007,111:8603-8610.
[15]Jun Zhang,Yupeng Zhang,Yinkai Lei,et al.Photocatalytic and degradation mechanisms of anatase Ti O2:a HRTEM study[J].Catal.Sci.Technol.,2011,1:273-278.
[16]WEN CHEN,LI QIANG MAI,JUN FENG PENG,et al.FTIR study of vanadiumoxide nanotubes from lamellar structure[J].J.MATER.SCI.,2004,39,2625-2627.
[17]A.Desmartin-Chomel,J.L.Flores,A.Bourane,et al.Calorimetric and FTIR Study of the Acid Properties of Sulfated Titanias[J].J.Phys.Chem.B,2006,110:858-863.
[18]Bert M.Weckhuysen,Daphne E.Keller.Chemistry,spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis[J].Catalysis Today,2003,78:25-46.
[19]Wonyong Choi,Andreas Termin,Michael R.Hoffmann.The Role of Metal Ion Dopants in Quantum-Sized Ti O2-Correlation between Photoreactivity and Charge Carrier Recombination Dynamics-Ion radius[J].J.Phys.Chem.,1994,98:13669-13679.
[20]Scot T.Martin,Colin L.Morrison,Michael R.Hoffmann.Photochemical Mechanism of Size-Quantized Vanadium-Doped Ti O2Particles[J].J.Phys.Chem.,1994,98:13695-13704.
[21]Jonathan Z.Bloh,Ralf Dillert,Detlef W.Bahnemann.Designing Optimal Metal-Doped Photocatalysts-Correlation between Photocatalytic Activity,Doping Ratio,and Particle Size[J].J.Phys.Chem.C,2012,116:25558-25562.
