CdS/TiO2纳米晶薄膜的原位法制备及光电化学性能研究  

CdS/TiO_2 Nanocrystalline Films: In-situ Synthesis and Photoelectrochemical Performance

作　　者：刘灿军 陈述[1] 李洁[2] LIU Can-Jun;CHEN Shu;LI Jie(Key Laboratory of Theoretical Chemistry and Molecular Simulation, Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)

机构地区：[1]湖南科技大学化学化工学院,理论有机化学与功能分子教育部重点实验室,湘潭411201 [2]中南大学化学化工学院,长沙410083

出　　处：《无机材料学报》2018年第12期1343-1348,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金 (51502088); 湖南省自然科学基金(2017JJ3079); 湖南省教育厅科学研究基金(17C0628).

摘　　要：CdS/TiO_2异质结薄膜因其优异的可见光催化性能,在光催化领域引起了广泛关注。然而,目前传统方法制备的CdS/TiO_2薄膜可能存在交界面结合不紧密的问题,不利于光生载流子在交界面处的传输。因此,本研究基于原位转换的原理(TiO_2→CdTiO_3→CdS),将TiO_2纳米晶表层原位转换成CdS,制备了CdS/TiO_2纳米晶薄膜。采用X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)手段对样品薄膜的形貌和结构进行了表征。由表征结果可知,在TiO_2纳米晶表面形成了CdS,构成了交界面结合紧密的CdS/TiO_2异质结薄膜。光电化学性能研究表明,与传统的连续离子层吸附反应法(SILAR)制备的薄膜相比,原位法制备的CdS/TiO_2薄膜的光电流密度更高,达到9.8 mA·cm^(–2)(V=0.4 V(vs.RHE));交流阻抗谱(EIS)结果表明,原位法制备的CdS/TiO_2薄膜具有更小的电荷传输电阻,说明原位法形成的CdS/TiO_2异质结结合更紧密,能减小光生载流子在CdS/TiO_2界面处的传输阻力,降低光生载流子在传输过程中的复合几率,进而提高CdS/TiO_2薄膜的光电化学性能。CdS/TiO 2 heterojunction films have attracted much attention in the field of photocatalysis due to their excellent photocatalytic performance under visible light irradiation. However, the CdS/TiO 2 films prepared by the conventional methods may exhibit loose interface, leading to poor transport of photogenerated carriers in the interface. In this study, CdS/TiO 2 heterojunction films were successfully prepared by in-situ transformation (TiO 2 →CdTiO 3 →CdS). Morphologies and structures of as-prepared films were characterized by XRD, SEM and TEM. Results show that CdS formed on the surface of TiO 2 nanoparticle, and the interface of CdS/TiO 2 heterojunction was compact. Their photoelectrochemical (PEC) performance was investigated by electrochemical working station.Results indicate that the CdS/TiO 2 films prepared by in-situ method, whose photocurrent density was as high as 9.8 mA·cm^-2 at 0.4 V (vs. RHE), present higher PEC activity than those prepared by successive ionic layer adsorption and reaction (SILAR). The electrochemical impedance spectroscopy (EIS) results show that the in-situ synthesized CdS/TiO 2 films own lowercharge transfer resistance, which reveals that the in-situ formed compact interface can reduce the charge transfer resistance in the CdS/TiO 2 interface, restrict the recombination of photo-induced carriers, and further enhance the PEC performance.

关 键 词：CDS/TIO2 光电化学性能 原位法 光阳极 异质结 

分 类 号：O644[理学—物理化学]