Synergizing Hydrogen Spillover and Deprotonation by Internal Polarization Field in MoS 2 /NiPS 3 Vertical Heterostructure for Boosted Water Electrolysis.

Hydrogen spillover has emerged to upgrade hydrogen evolution reaction (HER) activity of Pt-support electrocatalysts, but it is not applicable to the deprotonated oxygen evolution reaction (OER). Non-precious catalysts that can perform well in both hydrogen spillover and deprotonation are extremely desirable for sustainable hydrogen economy. Herein, an affordable MoS /NiPS vertical heterostructure catalyst is presented to synergize hydrogen spillover and deprotonation for efficient water electrolysis. Internal polarization field (IPF) is clarified as the driving force nature of hydrogen spillover in HER electrocatalysis. The hydrogen spillover from MoS edge to NiPS can activate the NiPS basal plane to boost the HER activity of MoS /NiPS heterostructure (112 mV versus RHE at 10 mA cm ). While for OER, the IPF in the heterostructure can facilitate the hydroxyl diffusion and render the NiPS -to-MoS /P-to-S dual-pathways for deprotonation. Resultantly, the stacking of OER-inactive MoS on the NiPS surface still brings intriguing OER enhancements. Serving them as electrode couples, the overall water splitting is attested stably with a cell voltage of 1.64 V at 10 mA cm . This research puts forward IPF as the criterion in the rational design of hydrogen spillover/deprotonation-unified non-precious catalysts for efficient water electrolysis. This article is protected by copyright. All rights reserved.