Co-catalyst and heterojunction dual strategies to induce photogenerated charge separation for efficient hydrogen evolution of CdS

The construction of heterojunctions is considered to be an important means to promote efficient electron-hole separation in photocatalysts. However, photocatalysts have poor light absorption ability and a relatively small chance of capturing H+, and the stability needs to be improved. In this work, a non-precious metal co-catalyst Cu3P was introduced for the successful construction of p-n heterojunctions from NiO and CdS to promote charge separation while expanding the light absorption capacity and increasing the chance of H+ capture, thus enhancing the photocatalytic hydrogen precipitation activity and stability. The overall photocatalytic performance was improved by continuously optimizing the loading of NiO and Cu3P. Satisfyingly, using a 5 W LED lamp as the light source, the hydrogen evolution rate of the composite photocatalyst 15NC@Cu-10 in 10 vol% lactic acid solution is 15 612.0 mu mol h(-1) g(-1), and the AQE reaches 10.4%. XPS analysis confirmed the direction and path of electron transfer. This synergistic strategy of co-catalyst modification of p-n heterojunctions provides a unique insight into the preparation of efficient and stable photocatalysts and also expands the applications of MOFs and their derivatives in the field of photocatalysis.

Automated summary

The construction of heterojunctions is an important means to improve the efficiency of photocatalysts. This study introduced a non-precious metal co-catalyst Cu3P to successfully construct p-n heterojunctions, which increased light absorption capacity and H+ capture, and improved photocatalytic hydrogen precipitation activity and stability. Continuously optimizing the loading of NiO and Cu3P further enhanced the overall photocatalytic performance.