Photoinduced Pt/BiVO<sub>4</sub>/Bi<sub>2</sub>O<sub>3</sub> Heterostructures for Methanol Oxidation and New Insights on the Photo-/Electrocatalysis Coupling Mechanism
Gong Wang, Xingming Xie, Xuejing Cui, Jing Liu, Luhua Jiang
Abstract
Methanol oxidation reaction (MOR), as the anodic reaction of direct methanol fuel cells (DMFCs), is sluggish in kinetics, which limits the fuel cell performance seriously. Coupling photocatalysis with electrocatalysis possibly promotes the MOR kinetics, yet it is challengeable due to the lack of well-designed photoelectrocatalysts and a poor understanding of the photo-/electrocatalysis coupling mechanism. Herein, a photoinduced strategy is reported to generate a Pt/BiVO4/Bi2O3 heterostructured catalyst, which displays superior photo-/electrocatalytic activity for the MOR under irradiation. The in situ-generated Pt/BiVO4/Bi2O3 heterostructured catalyst is efficient for photogenerated charge separation and transfer, taking advantage of both tailored band structures and compatible interfaces. The mechanism study discovers that the kinetics of methanol dehydrogenation on Pt is promoted by the photogenerated OHad on BiVO4/Bi2O3 heterojunctions, leading to a COad poison-free pathway. This work provides a new photoinduced strategy to synthesize heterostructured catalysts, and most importantly, the identification of the MOR pathway sheds light on the underlying photo-/electrocatalysis coupling mechanism, paving an avenue for the construction of high-performance DMFCs.