Surface hydroxy functionalized Pt/g-C3N4-CNS for highly efficient methanol electrocatalytic oxidation

Abstract

In this paper, CN(g-C3N4) and CNS(carbon nanosheets) were assembled by hydrothermal method to synthesize CN-CNS(g-C3N4-carbon nanosheets) composite carriers, then CN-CNS-x(g-C3N4-carbon nanosheets-mass of KOH(g)) carriers were prepared with KOH heat treatment. Finally, Pt nanoparticles were loaded onto the surface of CN-CNS-x carriers using NaBH4. The effect of the functionalized CN-CNS-x carriers on the catalytic performance of Pt/CN-CNS catalysts was investigated by electrochemical tests. It was demonstrated that Pt/CN-CNS-0.04(g-C3N4-carbon nanosheets-0.04g KOH) had the best electrocatalytic activity for methanol oxidation, with a specific activity of 123.58 mA/cm2 and the best stability among all catalysts. Through a series of characterization, it was found that the KOH treated CN-CNS carrier has a larger specific surface area, and the increased hydroxyl group on the carrier surface can interact with the Pt species, which helps the anchoring of Pt nanoparticles. Simultaneously, the hydroxyl groups on the carrier surface can accelerate the oxidation of CO, thus obtaining better electrocatalytic performance.