Synergistic effect of MoS2 and Ni9S8 nanosheets as an efficient electrocatalyst for hydrogen evolution reaction

A new heterostructure Ni9S8@MoS2 hybrid is studied as a promising candidate nonplatinum electrocatalyst for highly enhanced hydrogen evolution reaction (HER), prepared by an improved two-step hydrothermal method. Under optimized experiment conditions, the as-prepared catalysts exhibit significantly higher electrocatalytic activity than pure MoS2 and Ni9S8 nanosheets. The optimized Ni9S8@MoS2 hybrid shows a small onset overpotential of 88 mV, a Tafel slope as low as 49 mV/clec, and a good durability in acidic solution. Through experimental analysis, the excellent electrocatalytic activity of HER and high stability of the hybrid largely attribute to the electrical coupling between MoS2 and Ni9S8, the massive exposed active edge sites provided by layered transition metal chalcogenides (MoS2), and the electrocatalytic synergistic effects produced by the Ni9S8@MoS2 heterostructure. (C) 2019 Elsevier Inc. All rights reserved.