Noble metal-free ultrathin MoS2 nanosheet-decorated CdS nanorods as an efficient photocatalyst for spectacular hydrogen evolution under solar light irradiation

Abstract

Development of noble metal free, novel and highly efficient co-catalysts that favor high performance is of great significance towards elevated photocatalytic hydrogen production. The present existing technology for photocatalytic water splitting primarily involves the use of noble metals, such as Pt, as co-catalysts on semiconductor materials, resulting in significantly improved photocatalytic H₂ production. However, because of the high cost and low abundance of Pt, its practical use is limited. In this study, we synthesized noble metal free, novel and highly efficient ultrathin MoS₂ nanosheets-decorated CdS nanorods (UM/CdS) as a photocatalyst. We used a different and simple method instead of the usual preparation techniques for conversion of MoS₂ to ultrathin MoS₂; i.e. an ultrasonic method. Under optimized experimental conditions, the synthesized UM/CdS material exhibits an amazingly high rate of H₂ production of up to 174 mmol h⁻¹ g⁻¹ under natural solar light irradiation. The ultrathin MoS₂ nanosheets effectively separate the photo-generated charge carriers and improve the surface shuttling properties for efficient H₂ production via the active edge sites. Furthermore, the present H₂ evolution rate is much higher than that of noble metal (Pt) and bulk MoS₂-assisted CdS photocatalysts individually. Moreover, to the best of our knowledge, this is the highest H₂ production rate achieved by MoS₂-based CdS photocatalyst through the splitting of water under solar light irradiation. Considering its low cost and high efficiency, this photocatalytic system would have great potential for the expansion of highly efficient photocatalytic materials used in various fields.