钨基纳米片光电极的可控制备及其光电化学性能研究

发布时间：2018-11-15 11:43

【摘要】：化石能源的日益枯竭,迫使人们寻求新的方法获得可再生能源。钨基电极材料由于合适的带隙结构可用于光电化学分解水,但是单一钨基电极材料存在光电催化活性不高等弱点。本论文主要通过修饰非贵金属助催化剂和构筑三元异质结的策略来提高钨基电极材料的光电催化性能。主要工作如下:(1)我们发现分子配合物联吡啶-钴可显著提高WO3纳米片的光电催化活性。利用水热氧化及后煅烧处理路线,合成了具有三维结构的WO3纳米片光电极。以该WO3纳米片光电极为基底,采用水热沉淀法,制备出了 Co-dipy/W03纳米片复合光电极。相比WO3纳米片光电极,在0.5 M Na2SO4电解质中,该复合电极的光电催化性能在1.2 V(vsRHE)时提高了 1.89倍。此外,通过复合电极对磷酸根离子的吸附,利用磷酸根在光电催化分解水过程中作为质子受体的作用,Co-dipy/WO3复合光电极的光电催化性能进一步提升。利用分子助催化剂与磷酸根共修饰的策略,为设计新型高效光电极提供了新思路。(2)我们构筑了三元异质结Pt/In2S3/CdS/WSe2,可显著提高WSe2纳米片光电极的光电催化活性。通过化学气相沉积法制备出了 p型WSe2纳米片阵列电极。以该WSe2纳米片光电极为基底,通过水浴沉积,制备了 CdS/WSe2异质结。为了避免CdS发生光腐蚀并提升电极的表面催化活性,我们进一步通过水浴沉积与光电沉积的方法得到了Pt/In2S3/CdS/WSe2。该复合光电极,在 0.5MNa2SO4 电解质中,0.1V(vs RHE)时,将WSe2的光电催化活性提高了 4.2倍。(3)我们寻找到一种有效的非贵金属助催化剂CoSe2,将其负载在WSe2纳米片光电极上,可以显著提高WSe2的光电催化活性。以WSe2纳米片光电极为基底,采用水热沉积路径制备出了 CoSe2/WSe2。在0.5 M Na2S04电解质中,0.1 V(vs RHE)时,该助催化剂将WSe2的光电催化活性提高了 4.72倍,其光电催化活性可与Pt/WSe2媲美。
[Abstract]:The increasing depletion of fossil energy forces people to seek new ways to obtain renewable energy. Tungsten based electrode material can be used for photochemical decomposition of water due to its suitable bandgap structure, but the single tungsten based electrode material has some weaknesses such as low photocatalytic activity and so on. In this thesis, the photocatalytic properties of tungsten based electrode materials are improved by modifying non-noble metal cocatalyst and constructing ternary heterojunction. The main work is as follows: (1) We found that the molecular complex bipyridine-cobalt can significantly improve the photocatalytic activity of WO3 nanoparticles. By hydrothermal oxidation and post-calcination treatment, WO3 nanocrystalline photoelectrodes with three dimensional structure were synthesized. The composite photoelectrode of WO3 nanochip was prepared by hydrothermal precipitation method. Compared with the WO3 nanoscale photoelectrode, the photocatalytic performance of the composite electrode was 1.89 times higher than that of the WO3 nanoscale photoelectrode at 1. 2 V (vsRHE) in 0. 5 M Na2SO4 electrolyte. In addition, the photocatalytic performance of Co-dipy/WO3 composite photoelectrode was further improved by the adsorption of phosphate ion on the composite electrode and the role of phosphate as proton receptor in the process of photocatalytic decomposition of water. The strategy of co-modification of molecular cocatalyst and phosphate provides a new idea for the design of novel high efficiency photoelectrode. (2) We have constructed ternary heterojunction Pt/In2S3/CdS/WSe2, which can significantly improve the photocatalytic activity of WSe2 nanocrystalline photoelectrode. P-type WSe2 nanochip array electrodes were prepared by chemical vapor deposition. The CdS/WSe2 heterojunction was prepared by water bath deposition on the photovoltaic substrate of the WSe2 nanocrystalline. In order to avoid photoetching of CdS and enhance the surface catalytic activity of the electrode, we further obtained Pt/In2S3/CdS/WSe2. by water bath deposition and photodeposition. In the 0.5MNa2SO4 electrolyte, the photocatalytic activity of WSe2 was increased by 4.2 times at 0.1 V (vs RHE). (3) We found an effective non-precious metal co-catalyst CoSe2,. The photocatalytic activity of WSe2 can be significantly improved by loading it on the photoelectrode of WSe2 nanoparticles. CoSe2/WSe2. was prepared by hydrothermal deposition on the photovoltaic substrate of WSe2 nanocrystals. In 0.5 M Na2S04 electrolyte, the photocatalytic activity of WSe2 was increased by 4.72 times at 0.1 V (vs RHE). The photocatalytic activity of the co-catalyst was comparable to that of Pt/WSe2.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;O646.5

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