Plasma-liquid synthesized carbon-supported platinum nanoparticles as active electrocatalysts

•A microplasma-liquid interaction method is demonstrated for preparing Pt/C nanocatalysts.•The catalytic properties of the plasma-generated Pt/C NPs can be tuned by process control.•Maximum catalytic activity of 24.23 mA/cm2 can be achieved for MOR using the Pt/C-10% NPs.•Plasma-generated Pt/C NPs possess better electrochemical activity than commercial samples.•The obtained Pt/C NPs show good catalytic performance for HER in both acid and alkaline media. The preparation of carbon-supported platinum nanoparticles (Pt/C NPs) with excellent catalytic activities can greatly benefit both the fundamental research and industrial applications. However, the ability for rapid Pt/C NPs synthesis and engineering, especially in a simple, green, and controllable manner, remains essentially limited. Herein, Pt/C NPs were prepared via a microplasma-liquid interaction method from chloroplatinic acid solution and carbon black. Systematic experiments have been performed to investigate the synthesis process. Their catalytic performance was further evaluated via electrochemical reactions and measurements. Results revealed the successful synthesis of Pt/C nanoparticles, where small sized Pt nanoparticles (2∼3.6 nm) were well-dispersed over the carbon black. The formed Pt/C NPs have active electrocatalytic performance, and the electrochemically active surface area (ESA) can be tuned from 28.65 to 78.80 m2/g by adjusting the Pt content (3∼10%) through process control. A maximum catalytic activity of 24.23 mA/cm2 was achieved for methanol oxidation using the Pt/C-10%, better than commercial samples (ESA: 65.13 m2/g, MOR: 20.07 mA/cm2). Additionally, the Pt/C NPs for hydrogen evolution reaction (HER) exhibited small Tafel values in both the acid and alkaline solution. The demonstrated microplasma process is envisaged to be applicable for multiple functional nanomaterials synthesis. [Display omitted]