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 CO 2 photoreduction and water splitting photocatalysts are critical for closing the anthropogenic carbon cycle and developing H 2 energy source. Herein, ultrasmall pomegranate-like Z-scheme CdIn 2 S 4 /ZnIn 2 S 4 heterojunctions with abundant vacancies were rationally designed and in-situ constructed though L-cysteine assisted solvothermal method with precipitation conversion strategy. The obtained CdIn 2 S 4 /ZnIn 2 S 4 -3 photocatalyst displays the highest performance in the photocatalytic conversion of CO 2 and H 2 O into CO and H 2 with yields of 1194.5 and 475.7 μmolg −1 h −1 , respectively, which increase respectively by 62.2% and 123.1% compared to CdIn 2 S 4 under the visible light irradiation. In addition, CdIn 2 S 4 /ZnIn 2 S 4 -4 hybrid exhibits excellent stability and activity during the 23-hour continuous HER, the average yield of H 2 in 23-hour is up to 10286.6 μmolg −1 h −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.