Electro-optical-magnetic-thermal coupling branched plasmonic heterojunction for efficient electrocatalytic hydrogen evolution and its dynamic process.

[Display omitted] • Multi-branched AgAuPt is synthesized for cooperative system electrocatalysis. • The role of light and heat in enhancing catalytic activity is discussed separately. • The dynamic situation in catalytic processes is discussed and elucidated. • The proposed mechanism is explained in terms of the hopping rate of polarons. Electrocatalytic hydrogen evolution reaction (HER) represents a potential technology to solve environmental and energy concerns. However, the high overpotentials and sluggish kinetics remain an essential challenge for electrocatalytic HER. Being different from the complicated strategies of electrocatalyst preparation, the present study focuses on a simple and feasible approach to improve electrocatalytic HER activity through a cooperative catalytic system. Here, we report a kind of multi-branched AgAuPt plasmonic heterojunction. Under the irradiation of 808 nm near-infrared (NIR) light, the localized surface plasmon resonance (LSPR) effect and the photothermal effect induce magnetic field and increased temperature, and achieve electro-optical-magnetic-thermal coupling in the catalysts. In addition, the dynamic process of the cooperative catalytic system is investigated as the temperature gradually changes. The proposed mechanism of the dynamic process is discussed in terms of the hopping rate of polarons (K p). This work provides novel insights and inspirations into the design of cooperative catalytic system with improved electrocatalytic HER activity. [ABSTRACT FROM AUTHOR]