Electric Strain in Dual Metal Janus Nanosheets Induces Structural Phase Transition for Efficient Hydrogen Evolution

Summary The future of sustainable energy supply demands innovative breakthroughs in the design of cheap and durable catalysts for efficient electrochemical water splitting. Distinct from the conventional doping, defecting, and nanostructuring strategy, we develop a simple and feasible electric-strain way to trigger electrocatalyst's structural phase transition via regulating carrier distribution, realizing an excellent hydrogen evolution reaction (HER) performance. Herein, thanks to the intrinsic noncentrosymmetric polarization of our designed Janus MoReS3 nanostructures, large numbers of carriers are energetically pulled into the catalyst's interior to generate electric strain, leading to the deformation of the charged MoReS3 nanosheets and transition from T′ phase to another reversible atomic configuration (T″ phase) with higher catalytic activity and faster carrier transfer. The electric-strain-generated T″-MoReS3 shows HER performances in excess of a commercial Pt/C electrode at large current densities, reaching a current density of 150 mA cm−2 at an overpotential of 189 mV.