催化学报

催化学报 ›› 2020, Vol. 41 ›› Issue (3): 426-434.DOI: 10.1016/S1872-2067(19)63478-9

• 论文 • 上一篇    下一篇

新型间接Z字结型g-C3N4/Bi2MoO6/Bi空心微球等离子共振增强光吸收和光催化性能

李宁a,b,c, 高航b, 王鑫b, 赵苏君b, 吕达b, 杨国庆b, 高雪云b, 樊海宽b, 高旸钦b, 戈磊a,b   

  1. a 中国石油大学(北京)重质油国家重点实验室, 北京 102249;
    b 中国石油大学(北京)新能源与材料学院材料科学与工程系, 北京 102249;
    c 中国石油大学(北京)新能源与材料学院油气装备材料失效与腐蚀防护北京市重点实验室, 北京 102249
  • 收稿日期:2019-07-01 修回日期:2019-08-02 出版日期:2020-03-18 发布日期:2019-11-19
  • 通讯作者: 李宁, 戈磊
  • 基金资助:
    国家自然科学基金（51802351）.

Novel indirect Z-scheme g-C3N4/Bi2MoO6/Bi hollow microsphere heterojunctions with SPR-promoted visible absorption and highly enhanced photocatalytic performance

Ning Lia,b,c, Hang Gaob, Xin Wangb, Sujun Zhaob, Da Lvb, Guoqing Yangb, Xueyun Gaob, Haikuan Fanb, Yangqin Gaob, Lei Gea,b   

  1. a State Key Laboratory of Heavy Oil Processing, China University of Petroleum Beijing, No. 18 Fuxue RD, Beijing 102249, China;
    b Department of Materials Science and Engineering, College of New Energy and Material, China University of Petroleum Beijing, No. 18 Fuxue RD, Beijing 102249, China;
    c Beijing Key Laboratory of Failure, Corrosion, and Protection of Oil/Gas Facilities, College of New Energy and Material, China University of Petroleum Beijing, Beijing 102249, China
  • Received:2019-07-01 Revised:2019-08-02 Online:2020-03-18 Published:2019-11-19
  • Supported by:
    This work was financially supported by the Science Foundation of China University of Petroleum, Beijing (2462017YJRC048, 2462018BJC005), and the National Natural Science Foundation of China (51802351).

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摘要： 半导体光催化技术是目前最有前景的绿色化学技术，可通过利用太阳光降解污染物或制氢.作为有潜力的半导体催化剂，钼酸铋具有合适的带隙（2.58eV）.但是，由于低的量子产量，钼酸铋的光催化性能并不理想.为了提高钼酸铋的光催化性能，研究者多考虑采取构造异质结的方式.石墨相氮化碳（g-C3N4）能带位置合适，与多种光催化半导体能带匹配，是构造异质结的常用选择.因此，本文选用g-C3N4与钼酸铋复合，构造异质结结构.为了进一步提高光催化性能，多采用负载贵金属（Pt，Au和Pd）作为助催化剂，利用贵金属特有的等离子共振效应，增加光吸收，促进载流子分离，但贵金属价格昂贵.Bi金属单质价格便宜，具备等效的等离子共振效应，是理想的贵金属替代物.钼酸铋可以采取原位还原的方式还原出Bi单质，构造更紧密的界面结构，更有利于载流子传输.Bi的等离子共振效应可以有效提高材料的光吸收能力和光生载流子分离率.
本文采用溶剂热和原位还原方法成功合成了一种新型三元异质结结构g-C3N4/Bi2MoO6/Bi（CN/BMO/Bi）空心微球.结果显示，三元异质结结构的最佳配比为0.4CN/BMO/9Bi，该样品表现出最好的光催化降解罗丹明B效率，是纯钼酸铋的9倍.通过计算DRS和XPS的价带数据，0.4CN/BMO/9Bi是一种Z字型异质结.牺牲试剂实验也提供了Z字型异质结的有力证据，测试显示超氧自由基·O2-（在-0.33eV）是光催化降解的主要基团.但是，钼酸铋的导带位置低于-0.33eV，g-C3N4的导带高于-0.33eV，因此g-C3N4的导带是唯一的反应位点，从而证明了光生载流子的转移是通过Z字型异质结结构实现的.TEM图显示金属Bi分散在钼酸铋表面.DRS和PL图分析表明金属Bi增加了材料的光吸收能力，同时扮演了中间介质的角色，促进钼酸铋导带的电子和g-C3N4价带的空穴快速复合.因此，g-C3N4/Bi2MoO6/Bi的优异光催化性能主要归功于Z字型异质结和Bi金属的等离子共振吸收效应，提高了材料的光吸收能力和光生载流子分离率.

关键词: 钼酸铋, 石墨相氮化碳, 金属铋, Z字型异质结, 等离子共振效应, 罗丹明B, 可见光

Abstract: The surface plasmonic resonance (SPR) effect of Bi can effectively improve the light absorption abilities and photogenerated charge carrier separation rate. In this study, a novel ternary heterojunction of g-C3N4/Bi2MoO6/Bi (CN/BMO/Bi) hollow microsphere was successfully fabricated through solvothermal and in situ reduction methods. The results revealed that the optimal ternary 0.4CN/BMO/9Bi photocatalyst exhibited the highest photocatalytic efficiency toward rhodamine B (RhB) degradation with nine times that of pure BMO. The DRS and valence band of the X-ray photoelectron spectroscopy spectrum demonstrate that the band structure of 0.4CN/BMO/9Bi is a z-scheme structure. Quenching experiments also provided solid evidence that the ·O2- (at -0.33 eV) is the main species during dye degradation, and the conduction band of g-C3N4 is only the reaction site, demonstrating that the transfer of photogenerated charge carriers of g-C3N4/Bi2MoO6/Bi is through an indirect z-scheme structure. Thus, the enhanced photocatalytic performance was mainly ascribed to the synergetic effect of heterojunction structures between g-C3N4 and Bi2MoO6 and the SPR effect of Bi doping, resulting in better optical absorption ability and a lower combination rate of photogenerated charge carriers. The findings in this work provide insight into the synergism of heterostructures and the SPR absorption ability in wastewater treatment.

Key words: g-C3N4/Bi2MoO6/Bi, Z-scheme catalyst, Surface plasmonic resonance effect, Rhodamine B, Visible light