In-situ formed Cu-doped RuS2 hollow polyhedrons integrated with simultaneously heterostructure engineering with metallic Ru for boosting hydrogen evolution in alkaline media

Abstract

Promoting hydrogen evolution reaction (HER) in alkaline media is currently vital to practicing the sustainable development of hydrogen economy. As an emerging candidate, pyrite-structured ruthenium disulfide (RuS2) is a promising electrocatalyst for alkaline HER. Nevertheless, much less efforts have been devoted to RuS2, thus whose intrinsic properties still remain to be improved via promoting the water dissociation and hydrogen adsorption processes. Herein, we report the facile synthesis of Cu-doped RuS2 hollow polyhedrons coupled with metallic Ru from bimetallic MOF of RuCu-BTC to boost alkaline hydrogen evolution. In which, in-situ Cu doping integrated with simultaneous heterostructure engineering with metallic Ru are achieved for RuS2. Benefitting from modified electronic structure, heterogeneous interfaces and 3D hollow polyhedral morphology, the Cu-doped RuS2/Ru heterostructure exhibits admirable electrocatalytic activity with small overpotential of 169 mV at a high current density of 200 mA cm−2 in 1 M KOH, superior to that of commercial Pt/C. Density functional theory calculations indicate that the incorporation of Cu heteroatoms can not only decrease the energy barrier for water dissociation of RuS2 but also optimize its hydrogen adsorption. Simultaneously, the construction of heterointerfaces between RuS2 and metallic Ru demonstrates further improved conductivity, increased active sites and enhanced specific activity. This work discloses an innovative strategy for the simultaneous implementation of heteroatom doping and heterostructure engineering on RuS2 to collaboratively promote the HER electrocatalytic performance.