Rationally design and in-situ fabrication of ultrasmall pomegranate-like CdIn2S4/ZnIn2S4 Z-scheme heterojunction with abundant vacancies for improving CO2 reduction and water splitting

Exploring efficient and robust CO2 photoreduction and water splitting photocatalysts are critical for closing the anthropogenic carbon cycle and developing H2 energy source. Herein, ultrasmall pomegranate-like Z-scheme CdIn2S4/ZnIn2S4 heterojunctions with abundant vacancies were rationally designed and in-situ constructed though L-cysteine assisted solvothermal method with precipitation conversion strategy. The obtained CdIn2S4/ZnIn2S4-3 photocatalyst displays the highest performance in the photocatalytic conversion of CO2 and H2O into CO and H2 with yields of 1194.5 and 475.7 μmolg−1h−1, respectively, which increase respectively by 62.2% and 123.1% compared to CdIn2S4 under the visible light irradiation. In addition, CdIn2S4/ZnIn2S4-4 hybrid exhibits excellent stability and activity during the 23-hour continuous HER, the average yield of H2 in 23-hour is up to 10286.6 μmolg−1h−1. This study provides a practical method for in-situ fabrication of ultrasmall pomegranate-like Z-scheme nano-heterostructures with abundant vacancies, which are valuable for efficient and robust implementation in a wide range of environmental and energy applications.