Bifunctional Cobalt‐Doped ZnIn<sub>2</sub>S<sub>4</sub> Hierarchical Nanotubes Endow Noble‐Metal Cocatalyst‐Free Photocatalytic H<sub>2</sub> Production Coupled with Benzyl Alcohol Oxidation
Jierui Xue, Huanhuan Liu, Suyuan Zeng, Yafei Feng, Yangyang Zhang, Yin Zhu, Mingyu Cheng, Huaikun Zhang, Liang Shi, Genqiang Zhang
Abstract
Noble metals are widely used as cocatalysts to enhance the performance of photocatalysts, while large‐scale applications of noble metals are restricted due to their scarcity and high cost. In this context, it is an urgent task to design efficient noble‐metal cocatalyst‐free photocatalysts. Herein, the rational design and self‐sacrificial template‐assisted synthesis of cobalt‐doped ZnIn 2 S 4 hierarchical nanotubes (Co‐ZIS HNTs) are presented that can act as a bifunctional photocatalyst for H 2 evolution and benzaldehyde production. Comprehensive experimental results indicate that the Co‐ZIS HNTs can lead to the enhanced separation and transfer efficiency of photoinduced carriers. As a result, the Co‐ZIS HNTs exhibit a 1.93 times higher H 2 evolution rate than undoped ZnIn 2 S 4 microspheres (ZIS MSs) without any cocatalysts. Impressively, the Co‐ZIS HNTs show remarkable bifunctial photocatalytic activity toward both H 2 evolution and benzyl alcohol oxidation. The extraordinary production rates of H 2 and benzaldehyde are 2823.7 and 2769.0 μmol h −1 g −1 , which are 7.44 and 7.60 times higher than that of bare ZIS MSs under visible light, respectively. This work not only proposes a promising strategy to devise highly active cocatalyst‐free photocatalysts, but also illustrates the potential for H 2 evolution coupled with add‐valued products.