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

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 MoOx 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 MoOx 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.