Xu Jiachen, Li Qinran, Sui Dejian, Jiang Wei, Liu Fengqi, Gu Xiuquan, Zhao Yulong, Ying Pengzhan, Mao Liang, Cai Xiaoyan, Zhang Junying
School of Materials Science and Physics, China University of Mining and Technology, Xuzhou 221116, China.
School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, China.
Nanomaterials (Basel). 2023 Jan 19;13(3):420. doi: 10.3390/nano13030420.
The ternary metal sulfide CdInS (CIS) has great application potential in solar-to-hydrogen conversion due to its suitable band gap, good stability and low cost. However, the photocatalytic hydrogen (H) evolution performance of CIS is severely limited by the rapid electron-hole recombination originating from the slow photogenerated hole transfer kinetics. Herein, by simply depositing cobalt phosphate (CoHPO, noted as Co-Pi), a non-precious co-catalyst, an efficient pathway for accelerating the hole transfer process and subsequently promoting the H evolution reaction (HER) activity of CIS nanosheets is developed. X-ray photoelectron spectroscopy (XPS) reveals that the Co atoms of Co-Pi preferentially combine with the unsaturated S atoms of CIS to form Co-S bonds, which act as channels for fast hole extraction from CIS to Co-Pi. Electron paramagnetic resonance (EPR) and time-resolved photoluminescence (TRPL) showed that the introduction of Co-Pi on ultrathin CIS surface not only increases the probability of photogenerated holes arriving the catalyst surface, but also prolongs the charge carrier's lifetime by reducing the recombination of electrons and holes. Therefore, Co-Pi/CIS exhibits a satisfactory photocatalytic H evolution rate of 7.28 mmol g h under visible light, which is superior to the pristine CIS (2.62 mmol g h) and Pt modified CIS (3.73 mmol g h).
三元金属硫化物CdInS（CIS）由于其合适的带隙、良好的稳定性和低成本，在太阳能制氢转换方面具有巨大的应用潜力。然而，CIS的光催化析氢性能受到源于缓慢光生空穴转移动力学的快速电子-空穴复合的严重限制。在此，通过简单地沉积一种非贵金属助催化剂磷酸钴（CoHPO，记为Co-Pi），开发了一种加速空穴转移过程并随后促进CIS纳米片析氢反应（HER）活性的有效途径。X射线光电子能谱（XPS）表明，Co-Pi中的Co原子优先与CIS的不饱和S原子结合形成Co-S键，这些键充当了从CIS到Co-Pi快速提取空穴的通道。电子顺磁共振（EPR）和时间分辨光致发光（TRPL）表明，在超薄CIS表面引入Co-Pi不仅增加了光生空穴到达催化剂表面的概率，还通过减少电子和空穴的复合延长了载流子的寿命。因此，Co-Pi/CIS在可见光下表现出令人满意的光催化析氢速率，为7.28 mmol g⁻¹ h⁻¹，优于原始CIS（2.62 mmol g⁻¹ h⁻¹）和Pt修饰的CIS（3.73 mmol g⁻¹ h⁻¹）。
