In Situ Irradiated X-Ray Photoelectron Spectroscopy Investigation on a Direct Z-Scheme TiO2/CdS Composite Film Photocatalyst
In Situ Irradiated X-Ray Photoelectron Spectroscopy Investigation on a Direct Z-Scheme TiO2/CdS Composite Film Photocatalyst
复制标题
直接 Z 型 TiO2/CdS 复合薄膜光催化剂的原位辐照 X 射线光电子能谱研究
DOI：
10.1002/adma.201802981
复制
发表时间：
2019-02-08
影响因子：
29.4
通讯作者：
Yu, Jiaguo
中科院分区：
文献类型：
--
作者：
Low, Jingxiang;Dai, Benzhe;Yu, Jiaguo
受自然界的启发，通过构建直接Z方案光催化剂的人工光合作用由于在提高光转换效率方面的有效性而被广泛研究用于可持续的太阳能燃料生产。然而，仍然缺乏对这些光催化剂中直接Z-方案电荷转移的透彻理解和直接证据。本文以二氧化钛和硫化镉（TiO 2/CdS）为原料，制备了一种可回收的直接Z型复合膜，用于高效光催化还原二氧化碳（CO2）。原位辐照X射线光电子能谱（ISI-XPS）证实了光催化体系中的直接Z-方案电荷载流子迁移途径。此外，密度泛函理论模拟确定的内在原因形成的直接Z-计划之间的TiO 2和CdS的异质结。由于直接Z-方案系统中的电荷载体的氧化还原能力显著增强，优化的TiO 2/CdS的光催化CO2还原性能分别是CdS、TiO 2和商业TiO 2（P25）的3.5、5.4和6.3倍。本工作对制备高效可回收的光转换纳米复合材料具有指导意义。
Inspired by nature, artificial photosynthesis through the construction of direct Z-scheme photocatalysts is extensively studied for sustainable solar fuel production due to the effectiveness in enhancing photoconversion efficiency. However, there is still a lack of thorough understanding and direct evidence for the direct Z-scheme charge transfer in these photocatalysts. Herein, a recyclable direct Z-scheme composite film composed of titanium dioxide and cadmium sulfide (TiO2/CdS) is prepared for high-efficiency photocatalytic carbon dioxide (CO2) reduction. In situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) confirms the direct Z-scheme charge-carrier migration pathway in the photocatalytic system. Furthermore, density functional theory simulation identifies the intrinsic cause for the formation of the direct Z-scheme heterojunction between the TiO2 and the CdS. Thanks to the significantly enhanced redox abilities of the charge carriers in the direct Z-scheme system, the photocatalytic CO2 reduction performance of the optimized TiO2/CdS is 3.5, 5.4, and 6.3 times higher than that of CdS, TiO2, and commercial TiO2 (P25), respectively, in terms of methane production. This work is a valuable guideline in preparation of highly efficient recyclable nanocomposite for photoconversion applications.