Investigation of the Photoinduced Deposition Mechanism and Interfacial Properties Related to the Photoelectrochemical Performance of Pb/Cu–Au Bimetallic Nanocrystals
Investigation of the Photoinduced Deposition Mechanism and Interfacial Properties Related to the Photoelectrochemical Performance of Pb/Cu–Au Bimetallic Nanocrystals
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Pb/Cu−Au双金属纳米晶光诱导沉积机理及与光电化学性能相关的界面性质研究
DOI：
10.1149/1945-7111/ac5a18
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发表时间：
2022-03
影响因子：
3.9
通讯作者：
Songtian Li
中科院分区：
文献类型：
--
作者：
Haiyan Xu;Ziwei Sun;Jing Pei;Pengtao Sheng;Weili Li;Songtian Li
利用贵金属纳米晶对TiO 2进行修饰是提高其光电化学性能的有效方法。光沉积过程仍然是一个悬而未决的问题，需要进一步澄清。在此，我们选择性地将Pb或Cu沉积在由支化的TiO 2纳米结构支撑的Au纳米晶体上以制备Au@金属/半导体光催化剂。结果表明，光沉积机理与电解液类型有关。在乙酸-乙酸体系中，Pb在Au上的沉积经历了欠电位和过电位沉积过程，而Cu在Au上的沉积只表现出过电位沉积行为。然而，在硝酸-硝酸盐体系中，Pb在Au上的沉积仅发生欠电位沉积。表面微观结构分析表明，Cu-Au纳米晶为典型的核壳结构，Pb-Au纳米晶为Janus结构。Cu/Au-TiO_2的理想因子低于Pb/Au-TiO_2，表明Cu/Au-TiO_2是光电化学反应的理想光电极/电解质结，进一步增强了载流子输运，复合寿命短，为0.899 ms。最后，光电化学性能评价进一步证实了Cu/Au-TiO_2（Au负载量约0.55质量%）作为最佳光催化剂，效率高达0.29%，约为Au-TiO 2（0.15%）的1.93倍。
Modifying TiO2 with noble metal nanocrystals via photodeposition is an efficient strategy for improving its photoelectrochemical performance. The photodeposition process is still an open question and needs to be further clarified. Herein, we selectively deposited Pb or Cu on Au nanocrystals supported by the branched TiO2 nanostructure to prepare the Au@metal/semiconductor photocatalyst. The results revealed the dependence of the photodeposition mechanism on the type of electrolyte. In an acetic acid–acetate system Pb deposition on Au undergoes both underpotential and overpotential deposition processes, while Cu deposition on Au only displays overpotential deposition behavior. In a nitric acid–nitrate system, however, only underpotential deposition occurs during Pb deposition on Au. Surface microstructure analysis shows that the Cu–Au bimetallic nanocrystals form a typical core/shell structure, while Pb–Au has a Janus structure. The lower ideality factor of Cu/Au–TiO2 than that of Pb/Au–TiO2 indicates an ideal photoelectrode/electrolyte junction for photoelectrochemical reaction, further enhancing carrier transport with a short recombination lifetime of 0.899 ms. Finally, the evaluation of photoelectrochemical performance further confirmed Cu/Au–TiO2 (Au loading amount of about 0.55 mass%) as the optimal photocatalyst, with an efficiency as high as 0.29% or about 1.93 times that of Au–TiO2 (0.15%).