Enhanced photoelectrocatalytic performance of LaNiO3 sensitized with CdSe quantum dots for photoelectrochemical water splitting

CdSe Quantum Dots (QDs) are promising photocatalyst in the visible region and oxide perovskites like LaNiO3 (LNO) are one of the best materials for photoelectrochemical water splitting. In this work, we have successfully synthesized the LNO@CdSe hetero-junction by the impregnation method. Formation of LNO@CdSe hetero-junction was characterized by using physicochemical techniques such as XRD, UV-DRS, FE-SEM, XPS and HRTEM. These results confirmed the successful formation of the LNO@CdSe hetero-junction. Photoanodes were fabricated by the drop-casting method to perform their photoelectrochemical properties toward water splitting. LNO@CdSe hetero-junction exhibits photocurrent density with 1.11 mA/cm2 at 0.8 V vs. SCE, which is a 4.62-fold enhancement compared to bare LNO. The enhanced photoelectrochemical properties is due to the formation of hetero-junction with visible light absorbing CdSe QDs. Besides, LNO absorbs the light in the near infra-red region. Hence, the LNO@CdSe hereto-junction absorbs the light from the visible to near infra-red region. In addition to that, the band alignment of the hetero-junction is favourable for the transformation of photogenerated electrons from the conduction band of CdSe QDs to the conduction band of the LNO, which results in the lesser recombination of the electron/hole pairs. This work suggests, this material can be a potential candidate in near future for green hydrogen and oxygen production using solar energy.