One-step synthesis in deep eutectic solvents of PtV alloy nanonetworks on carbon nanotubes with enhanced methanol electrooxidation performance

Abstract

We report a simple one-step chemical reduction strategy in deep eutectic solvents (DESs) for the fabrication of a PtV alloy nanonetwork (ANN)/multiwalled carbon nanotube (MWCNT) nanohybrid, which exhibits excellent electrocatalytic performance in both activity and stability for the methanol oxidation reaction (MOR). The as-synthesized nanohybrid was characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy, confirming the formation of a porous nanonetwork structure composed of smaller PtV alloy nanoparticles (~3.8 nm) and the presence of strong electronic transfer interactions between Pt and alloyed V. The electrochemical properties of catalysts for the MOR were evaluated by using cyclic voltammetry and chronoamperometry techniques. The electrocatalytic activity, durability and CO tolerance ability of PtV ANNs/MWCNTs toward the MOR are found to be considerably higher than those of the Pt/MWCNT and commercial Pt/C catalysts. This investigation of the effect of several reaction parameters (e.g., scan rate and methanol concentration) indicates that the electrocatalytic oxidation of methanol on PtV ANNs/MWCNTs is a diffusion-controlled electrochemical process. The performance enhancement mechanism of MOR on the PtV ANN/MWCNT catalyst is analyzed based on the structure and electrochemical studies.