Ultrafast flash joule heating synthesis of the Pt/MoOx heterostructure for enhancing the electrocatalytic hydrogen evolution reaction

Abstract

The metal–support interaction of heterogeneous catalysts has garnered significant attention due to its role in boosting electrocatalytic efficiency. Herein, we synthesized uniformly dispersed Pt nanoparticles decorated on a MoO_x support by an ultrafast flash joule heating method. This method enables the simultaneous loading of metal and modification of support structures in a controllable, ultrafast manner. The optimal catalyst demonstrates exceptional performance in the hydrogen evolution reaction (HER) under acidic conditions, characterized by a low overpotential of only 55.08 mV to achieve a current density of 100 mA cm⁻², a Tafel slope of 19.94 mV dec⁻¹, and a significant mass activity of 13.80 A mg_Pt⁻¹ at 50 mV vs. RHE. In addition, the optimal catalyst exhibits better stability for the HER than a commercial 20 wt% Pt/C catalyst. The spectroscopic characterization confirms the charge transfer between the metal and support, leading to a near-zero valence state of Pt in the optimal catalyst. Density functional theory calculations further corroborate that the metal–support interaction between Pt and MoO_x leads to a suitable hydrogen adsorption free energy at the interfacial Pt site, which results in accelerating the reaction kinetics of the HER. This work aims to design and develop a metal–support heterostructure with high HER activity and stability, and provides a strategy for engineering crystalline structures and electronic configurations using an ultrafast flash Joule heating synthesis method.