Embedding Pt in Ni-MOF/CdS organic-inorganic hybrid materials as electron channel to promote photogenerated carrier separation for enhanced photocatalytic hydrogen evolution under visible light

Abstract

CdS exhibits a high photogenerated carrier yield, yet it is susceptible to photocorrosion due to the limited number of active sites. Ni-MOF boasts a considerable specific surface area and a plethora of active sites, yet it displays a low photogenerated carrier yield and suboptimal conductivity. In this study, the incorporation of Pt into a Ni-MOF/Pt/CdS hybrid material served as an electron transport channel, effectively addressing the limitations of CdS, Ni-MOF, and electrical conductivity. The results of electrochemical tests demonstrate that the electron transport and separation efficiency of the hybridised material is noteworthy. Following the performance test, the optimal visible photocatalytic hydrogen evolution rate of the Ni-MOF/Pt/CdS hybrid material was found to be 14.1 mmol h⁻¹g⁻¹, representing a significant enhancement of approximately 61.3 times compared to that of pure CdS. Furthermore, XPS analysis indicates the presence of Pt-S bonds, which effectively inhibit the oxidation of S²⁻ to S on the CdS surface, thus alleviating the photocorrosion phenomenon and enhancing the cycling stability. This level of stability is maintained at 92.6 % after five cycles. This work offers a novel approach to addressing the limitations of inorganic catalysts, including the scarcity of active sites and the low photogenerated carrier yield, as well as the poor conductivity observed in organic catalysts.