Ultrathin MoS2 layers anchored exfoliated reduced graphene oxide nanosheet hybrid as a highly efficient cocatalyst for CdS nanorods towards enhanced photocatalytic hydrogen production

Abstract

The development of novel highly efficient noble metal-free co-catalysts for enhanced photocatalytic hydrogen production is of great importance. Herein, we report the synthesis of novel and highly efficient noble metal-free ultra-thin MoS2 (UM) layers on exfoliated reduced graphene oxide (ERGO) nanosheets as a cocatalyst for CdS nanorods (ERGO/ UM/ CdS). A simple method different from the usual preparation techniques is used to convert MoS2 to UM layers, graphene oxide (GO) to ERGO nanosheets, based on ultrasonication in the absence of any external reducing agents. The structure, optical properties, chemical states, and dispersion of MoS2 and CdS on ERGO are determined using diverse analytical techniques. The photocatalytic activity of as-synthesized ERGO/ UM/ CdS composites is assessed by the splitting of water to generate H-2 under simulated solar light irradiation in the presence of lactic acid as a hole (h+) scavenger. The observed extraordinary hydrogen production rate of similar to 234 mmol h(-1) g(-1) is due to the synergetic effect of the ultrathin MoS2 layers and ERGO, which leads to the effective separation of photogenerated charge carriers and improves the surface shuttling properties for efficient H-2 production. Furthermore, the observed H-2 evolution rate is much higher than that for individual noble metal (Pt), ERGO and MoS(2)assisted CdS photocatalysts. Moreover, to the best of our knowledge, this is the highest H-2 production rate achieved by a RGO and MoS2 based CdS photocatalyst for water splitting under solar light irradiation. Considering its low cost and high efficiency, this system has great potential for the development of highly efficient photocatalysts used in various fields (C) 2017 Elsevier B.V. All rights reserved.