导　　师： 周保学

学科专业： 0830

授予学位： 硕士

作　　者： ;

机构地区： 上海交通大学

摘　　要： WO3是窄带系半导体材料/(2.5-3.0eV/)，对波长为400-500nm的可见光有着良好的响应，此外WO3拥有良好的稳定性，因此在光催化领域中得到了广泛的关注。WO3纳米材料更是由于纳米结构的特性使其具有更佳的光催化能力。阳极氧化的方法具有简易、快速和易于调控的特点，是广为使用的一种纳米材料制备技术。相较于传统的纳米薄膜，利用阳极氧化技术制备的金属钨基三氧化钨/(WO3//W/)纳米孔薄膜材料，由于金属钨与纳米薄膜层的自然结合，具有更好的光生电子传输性能，因而成为近年来的研究的热点。本论文重点研究了WO3//W纳米孔薄膜电极材料的阳极氧化制备方法及其光电催化性能。在此基础之上，通过光沉积的方法在WO3//W纳米孔薄膜电极表面沉积了Co-Pi催化剂，以提高其光电催化性能和稳定性。 本文在含有0.3/%HF和0.3wt./%NaF的水溶液电解质体系中，研究了阳极氧化制备WO3//W纳米孔薄膜电极的影响因素。WO3//W纳米孔薄膜电极的电镜扫描图/(SEM/)和线性伏安扫描曲线/(I-V/)研究表明，影响电极制备的因素有电解液体系的组成、阳极氧化电压、阳极氧化时间等。在该体系中可以制备出纳米孔孔径在50-100nm左右，孔结构分布均匀，形貌规整的WO3//W纳米孔薄膜电极，制备的最佳条件为：阳极氧化电压为60V，阳极氧化时间为60min。这种WO3//W纳米孔薄膜电极可以表现出良好的光电催化性能，在外加电压达到1.0V时，光电流可达到2.4mA，光能量转化效率达到60/%。 在此基础上，本文利用光辅助沉积的方法在WO3//W纳米孔薄膜电极表面进行了Co-Pi催化剂的沉积改性，并通过线性伏安扫描曲线/(I-V/)，光转化效率，稳定度，紫外可见漫反射光谱/(UV-vis/)和X射线光电子能谱分析/(XPS/)等方法对其进行了测试。沉积Co-Pi催化剂后的WO3//W纳米孔薄膜电极相比较单一的WO3//W纳米孔薄膜电极，在同一外加电压的条件下，光电流明显增大，光转化效率提高15/%。对其进行电流-时间/(I-T/)曲线扫描，沉积Co-Pi催化剂后的WO3//W纳米孔薄膜电极稳定度明显提高，在长时间使用的情况下，光电流保持相对的稳定性。 WO3is one kind of narrow band semiconductor /(2.5-3.0eV/) and hasa good response to the visible light of400-500nm. It has received muchresearch and attention due to the excellent photocatalytic activity. Anodicoxidation method is a simple, fast, and easy-to-control way to prepare thenanometer materials. Compared to the conventional technology, thenanoporous WO3//W thin film prepared by Anodic oxidation method hasa natural combination between the tungsten and thin film layer whichmake the WO3//W nanoporous thin film show good optoelectronictransmission performance. This thesis studied the preparation ognanoporous WO3//W thin film by anodization and tested thephotoelectrochemical performance. In order to improve the performanceof nanoporous WO3//W thin film, nanoporous WO3//W photoanodemodified with cobalt–phosphate /(Co–Pi/) catalyst was synthesized in thisstudy. In this thesis, we studied the main factors influencing thenanoporous WO3//W thin film in the process. Through the ScanningElectron Microscope /(SEM/) and Linear volt-ampere scanning curve /(I-V/),we found that the main factors include the electrolyte composition,anodizing voltage, anodizing time. The conditions for preparingnanoporous WO3//W thin film in aqueous solution are: electrolytecomposition of0.3wt/%NaF,0.3/%HF, anodizing voltage of60V, anodicoxidation time of60min. The pore diameter of nanoporous WO3//W thin film was at50-100nm with uniform distribution and well-definedstructure. When the applied voltage reaches1.0V, the photocurrent wasup to2.4mA, which indicated that nanoporous WO3//W thin film exhibitsexcellent catalytic performance. Herein, we present a photo-assisted electrodeposition of Co–Picatalyst on nanoporous WO3//W thin film for photoelectrochemical watersplitting and characterized the Co-Pi//WO3by linear sweep voltammetrycurves /(I-V/), light conversion efficiency, stability, UV-visible diffusereflectance spectroscopy /(UV-vis/) and X-ray photoelectron spectroscopy/(XPS/). The photocurrent density of Co-Pi//WO3was much higher thansingle nanoporous WO3//W. The light conversion efficiency of Co-Pi//WO3increased by15/%compared with the nanoporous WO3//W thin film.Through the current-time curve, we found that Co-Pi//WO3was morestable than single nanoporous WO3//W thin film.

关 键 词： 纳米孔薄膜电极 表面改性 光电沉积 光电催化 光解水

分 类 号： [TB383.2 O614.613]

领　　域： [一般工业技术] [理学] [理学]