Engineering active and robust alloy-based electrocatalyst by rapid Joule-heating toward ampere-level hydrogen evolution.

Rational design of bimetallic alloy is an effective way to improve the electrocatalytic activity and stability of Mo-based cathode for ampere-level hydrogen evolution. However, it is still critical to realise desirable syntheses due to the wide reduction potentials between different metal elements and uncontrollable nucleation processes. Herein, we propose a rapid Joule heating method to effectively load RuMo alloy onto MoOx matrix. As-prepared catalyst exhibits excellent stability (2000 h @ 1000 mA cm -2 ) and ultralow overpotential (9 mV, 18 mV and 15 mV in 1 M KOH, 1 M PBS, 0.5 M H 2 SO 4 solution, respectively) at 10 mA cm -2 . Based on first-principle simulations and operando measurements, the impressive electrocatalytic stability and activity are investigated. And the role of rapid Joule heating method is highlighted and discussed in details. This study showcases rapid Joule heating as a feasible strategy to construct highly efficient alloy-based electrocatalysts.