One-step synthesis of monodispersed Pt nanoparticles anchored on 3D graphene foams and its application for electrocatalytic hydrogen evolution

Abstract

Although platinum-based materials are regarded as the state-of-the-art electro-catalysts for hydrogen evolution reaction (HER), high cost and quantity scarcity hamper their scale-up utilization in industrial deployment. Herein, a one-step strategy was developed to synthesize multi-walled carbon nanotubes and reduced graphene oxide supported Pt nanoparticle hydrogel (PtNP/rGO-MWCNT), in which only ascorbic acid was used as the reductant for one-pot reduction of both GO and chloroplatinic acid. The hydrogel can be directly used as a flexible binder-free catalytic electrode to achieve high performance of HER. Compared to conventional strategies, the current strategy not only significantly reduces the Pt loading to 3.48 wt%, simplifies the synthesis process, but also eliminates the use of any polymer binders, thus decreasing the series resistance and improving catalytic activity. An overpotential of only 11 mV was achieved on as-prepared PtNP/rGO-MWCNT to drive a geometrical current density of 10 mA/cm2 in 0.5 mol/L H2SO4, with its catalytic activity being kept over 15 h. In acidic medium, the HER activity of the PtNP/rGO-MWCNT catalyst exceeds most of the reported Pt-based electro-catalysts and is 3-fold higher than that obtained on commercial Pt/C electrode.