Defect Engineering and Phase Junction Architecture of Wide-Bandgap ZnS for Conflicting Visible Light Activity in Photocatalytic H2 Evolution

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• 作者：Zhibin Fang ; Sunxian Weng ; Xinxin Ye ; Wenhui Feng ; Zuyang Zheng ; Meiliang Lu ; Sen Lin ; Xianzhi Fu ; Ping Liu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：July 1, 2015
• 年：2015
• 卷：7
• 期：25
• 页码：13915-13924
• 全文大小：564K
• ISSN：1944-8252

文摘

ZnS is among the superior photocatalysts for H₂ evolution, whereas the wide bandgap restricts its performance to only UV region. Herein, defect engineering and phase junction architecture from a controllable phase transformation enable ZnS to achieve the conflicting visible-light-driven activities for H₂ evolution. On the basis of first-principle density functional theory calculations, electron spin resonance and photoluminescence results, etc., it is initially proposed that the regulated sulfur vacancies in wurtzite phase of ZnS play the key role of photosensitization units for charge generation in visible light and active sites for effective electron utilization. The symbiotic sphalerite-wurtzite phase junctions that dominate the charge-transfer kinetics for photoexciton separation are the indispensable configuration in the present systems. Neither ZnS samples without phase junction nor those without enough sulfur vacancies conduct visible-light photocatalytic H₂ evolution, while the one with optimized phase junctions and maximum sulfur vacancies shows considerable photocatalytic activity. This work will not only contribute to the realization of visible light photocatalysis for wide-bandgap semiconductors but also broaden the vision on the design of highly efficient transition metal sulfide photocatalysts.