CZTS/MoS2-rGO Heterostructures: An efficient and highly stable electrocatalyst for enhanced hydrogen generation reactions

Abstract

The design and intensification of inexpensive highly efficient electrocatalysts for hydrogen production underpins numerous promising clean-energy technologies. In this work we have demonstrated facile sonochemical approach for novel heterostructured electrocatalyst consisting of MoS 2 -rGO coupled with Cu 2 ZnSnS 4 (CZTS) NPs (CZTS/MoS 2 -rGO) for enhanced hydrogen generation reactions (HER). The CZTS/MoS 2 -rGO heterostructured electrocatalyst exhibits the highest HER activity, i.e. potential of 50 mV vs. RHE at 10 mA cm −2 , Tafel slope of 68 mV dec −1 and it reveals the Volmer-Heyrovsky mechanism for HER. The electrochemical impedence spectroscopy (EIS) showed smaller semicircle (R ct = 4.5 Ω) with excellent stability upto the ~6 h confirmed from chronoamperometric (i-t) measurements. Such a high HER activity is superior than most of CZTS based electrocatalysts reported so far, and attributed to the presence of MoS 2 -rGO with augmented charge severance by rGO and a higher number of catalytically active edges from MoS 2 further improves the electrocatalytic performance of CZTS and which demonstrating synergestic effect leading to the enhanced electrical conductivity. This work demonstrates promising performance of MoS 2 and rGO on HER activity of CZTS based catalysts. • An economical fabrication of sonochemical CZTS/MoS 2 -rGO electrocatalyst • Electrocatalytically converting H 2 O into H 2 with high energy efficiency is proposed. • CZTS/MoS 2 -rGO electrocatalyst is shown to be superior for HER compared to CZTS • This article explore the non precious metal highly stable electrocatalytic system for HER