Photo-enhanced electrocatalytic methanol oxidation of carbon black-modified Pt and Mo-based oxide for acidic and basic solutions

Abstract

Pt nanoparticles were electrodeposited on a molybdenum-based oxide (e.g., molybdenum oxide (MoO3) and bismuth molybdate (Bi2MoO6)) modified carbon black (CB) support to study the enhancement of methanol oxidation in acidic and basic solutions with the assistance of visible light illumination. Morphology studies showed that Bi2MoO6 nanoparticles were initially anchored on the CB matrix with round 2.2 nm Pt nanoparticle decoration, resulting in a large extension of the specific active catalytic surface area (SSA) for Pt/Bi2MoO6/CB. It was found that the Pt/Bi2MoO6/CB composite catalyst offered the highest electrocatalytic activity with visible light support, showing 2 (in an acidic solution) and 18 (in a basic solution) times higher reactivity than the electrodeposited Pt/CB. Moreover, the electrocatalytic activity and stability of the prepared catalyst toward methanol oxidation with the aid of visible light were noticeably improved in both acidic and basic solutions, and the oxidation improvement was greatest in basic solutions. Therefore, the improved oxidation performance of the prepared catalysts was mostly a result of the combination of both photocatalytic and electrocatalytic procedures on Pt-based catalysts with metal oxides, resulting in enhanced catalytic activity and stability for the oxidation of methanol and CO under visible light.