Rapid photothermal reduction-derived Pt1.6Ni nanoalloys embedded in laser-induced graphene for hydrogen evolution reaction

Abstract

Water electrolysis is one of the most intriguing technologies for hydrogen production because of its carbon-neutral nature, however the development of efficient electrocatalysts is required to improve the energy conversion efficiency of water splitting. In this study, we suggest a facile route for the fabrication of Pt1.6Ni nanoalloys on laser-induced graphene (Pt1.6Ni NAs/LIG) by the photothermal reduction using commercial CO2 laser which is irradiated on the surface of the LIG. The laser ablation process on the polyimide (PI) film resulted in porous and interconnected graphene sheets, while uniform nanoparticles with an average size of around 4.5 nm were decorated on their surface by the photothermal reduction effect. The overall process took only 60 s. Bonding structure investigation confirmed that PI film was successfully transformed into a graphene structure and the metal precursors were converted into bimetallic nanoalloy by using Raman spectroscopy and XPS, respectively. Electrochemical measurements for hydrogen evolution reaction discovered that the Pt1.6Ni NAs/LIG showed superior catalytic performance which required an overpotential of only 96 mV to achieve a current density of 10 mA cm−2. It exhibited superior catalytic activity compared to LIG (740 mV), Pt NPs/LIG (204 mV), and PtNi1.6 NAs/LIG (205 mV), as well as other previously reported catalysts at the same current density. Based on these results, the Pt1.6Ni NAs/LIG was employed for hydrogen gas collection and detection. The generated bubbles were collected separately from both electrodes, and their compositions with evolution rate were confirmed to be hydrogen using a commercial H2 sensor.