Interface engineering of NixSy@MoS2 heterostructured nanorods as high-efficient electrocatalysts for water splitting

Abstract

Robust and low-cost oxygen evolution reaction (OER) electrocatalysts at low overpotentials play an increasingly pivotal role in clean energy storage and conversion systems. The emerging catalyst with core-shell heterostructure has excited the potentiality of non-noble-metal candidates. Herein, in order to enhance the sufficient exposure and utilization of actives sites and accelerate the electron transfer rate of catalyst, NixSy@MoS2 core-shell nanorods decorated NiSe2 framework (NixSy@MoS2/NiSe2) electrocatalyst has been successfully prepared via interface engineering. As expected, the as-prepared catalyst shows an outstanding OER activity with a small overpotential of 360 mV to drive 100 mA cm−2 and a Tafel slope of 64 mV dec−1. More importantly, a low cell voltage of 1.40 V is achieved for the NixSy@MoS2/NiSe2 based water splitting electrolyzer at 10 mA cm−2, and it shows negligible decrement after continuous operation for 100 h. Furthermore, density functional theory (DFT) calculations further uncovered the synergetic catalytic effect between the NixSy@MoS2 core-shell nanorods and the NiSe2 framework played a key role in generating more charge carriers and declining the energy barriers in the process of forming intermediates.