CoSe as non-noble-metal cocatalyst integrated with heterojunction photosensitizer for inexpensive H2 production under visible light

• Published in: Journal of catalysis 2020-10, Vol.390, p.196-205
• Main Authors: Irfan, Rana Muhammad, Tahir, Mudassir Hussain, Maqsood, Mudassar, Lin, Yanping, Bashir, Tariq, Iqbal, Shahid, Zhao, Jianqing, Gao, Lijun, Haroon, Muhammad
• Format: Article
• Language: English
• Subjects: Charge separation; Cocatalyst; CoSe; H2 production; ZnSe/CdS
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2020.07.034

[Display omitted] •Unique core/shell ternary photocatalyst based on noble-metal-free CoSe was synthesized successfully.•Facile aqueous solution method was used.•Synergistic effect of ZnSe and CoSe enhanced the H2 evolution rate to 785 µmol h−1 under optimal conditions.•Apparent quantum yield was boosted to 55.3% at monochromatic 420 nm light.•Based on spectroscopic and electrochemical results a proposed mechanism has also been discussed. The development of inexpensive cocatalysts based on earth-abundant-elements, is highly demanding strategy to produce large-scale photocatalytic H2 for real-life applications. Herein, we report the utilization of CoSe as a highly efficient cocatalyst to significantly improve the photocatalytic H2 production on ZnSe/CdS under visible irradiation. The maximum H2 production rate of 785 μmol h−1 was attained under optimized conditions. Furthermore, the current system showed robust stability up to 30 h of irradiation and more than 23 mmol of H2 was produced. The highest apparent quantum yield of the system was 55.3% at monochromatic 420 nm light. Photocurrent responses, UV–vis diffuse reflectance absorption spectroscopy, electrochemical impedance spectroscopy and photoluminescence (PL) spectroscopy were used to explain the mechanistic roles of CoSe and ZnSe in current photocatalytic system. This work showcased the successful usage of CoSe as cocatalyst and ZnSe as visible light active semiconductor for inexpensive conversion of solar energy to H2.