论文总字数：19762字

摘 要

随着人们对能源需求的不断增长和世界燃料储备的不断减少，高效利用太阳能的技术越来越受到重视。光电催化分解水制氢的技术由于具有高效、清洁无污染、原材料价格低廉等众多优势，目前正受到广泛关注。这个技术的关键点在于寻找并开发合适的光催化剂。光电催化分解水的工作电极需要具有以下几个特点：具有较小的禁带宽度使之具备可见光响应能力；光生电子-空穴对能有效分离以保证载流子定向迁移；具有高度催化能力以便充分利用分离的载流子。

BiVO₄由于其合适的可见光响应，已成为新型半导体光电催化剂。本实验选用带隙约为2.4 eV的单斜相BiVO₄作为半导体催化剂，将其涂覆在FTO导电玻璃上制成光催化电极。并且对BiVO₄进行Mo掺杂来提高它的光催化性能。之后对制备出的BiVO₄光阳极进行X-射线衍射实验，分析其衍射图谱，利用布拉格公式确定晶体的结构和衍射空间方位。再运用显微镜观察晶体表面的形貌特点。之后用紫外分光光度计测定BiVO₄样品的光吸收曲线，分析其禁带宽度。最后进行光电催化制氢试验，测量光电流密度曲线，计算光电催化效率。

关键词：光电催化 可见光响应 BiVO₄光电极 禁带宽度

Abstract

As the demand for energy grows and the world's fuel reserves dwindle, more attention is being paid to the efficient use of solar energy. Photocatalytic decomposition of water for hydrogen production technology due to high efficiency, clean and pollution-free, low prices of raw materials and many other advantages, is now widely concerned. The key point of this technique is to find and develop suitable photocatalysts. The working electrode for photocatalytic water decomposition needs to have the following characteristics: a small band gap to enable it to absorb visible light; The photogenic electron-hole pair can be separated effectively to ensure the orientation migration of carriers. High catalytic capacity to make full use of the separated carriers.

Due to its suitable visible light response, BiVO₄ has become a new type of semiconductor photocatalyst. In this experiment, monoskew BiVO₄ with a band gap of about 2.4 eV was selected as a semiconductor catalyst and coated on FTO conductive glass to make a photocatalytic electrode. Moreover, doping Mo in BiVO₄ can improve its photocatalytic performance. Afterwards, X-ray diffraction experiments were carried out on the prepared BiVO₄ photoanode to analyze its diffraction pattern, and Bragg formula was used to determine the crystal structure and diffraction spatial orientation. The morphology of crystal surface was observed by microscope. Then the absorption curve of BiVO₄ sample was measured by ultraviolet spectrophotometer, and the forbidden band width was analyzed. Finally, the photocatalytic hydrogen production experiment was carried out to measure the photocurrent curve and the total amount of gas, and the photocatalytic efficiency was calculated.

Key words: photocatalytic;visible light response;BiVO₄ ;forbidden band width

目录

第一章 绪论 1

1.1引言 1

1.2光电催化分解水的基本原理 1

1.3光电催化性能的表征参数 3

1.4影响光电催化性能的主要因素 4

1.4.1半导体的能带位置 4

1.4.2电子-空穴对的有效分离与复合损耗 5

1.4.3晶体结构 6

1.4.4晶格缺陷 7

1.4.5晶体形貌特点 7

1.5提高光电催化性能的方法 7

1.5.1元素掺杂 8

1.5.2构造半导体异质结 8

1.5.3优化半导体晶体表面形貌 8

1.6选题意义及研究内容 9

第二章 实验仪器及试剂 10

2.1实验仪器 10

2.2实验试剂 11

2.3 BiVO₄光电极的物相性能表征方法 11

2.3.1 X-射线衍射（XRD）实验 11

2.3.2 吸收光谱实验 11

2.3.3 金相显微镜观察实验 12

第三章BiVO₄光电极的制备及光电化学性能 13

3.1引言 13

3.2原料的准备 13

3.3实验部分 13

3.2.1 BiVO₄光电极的制备 13

3.2.2 BiVO₄光电极的性能表征 14

3.4结果与讨论 15

3.5本章小结 19

总结与展望 20

参考文献 21

致谢 24

第一章 绪论

1.1引言

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