Gong Wang^#, Xingming Xie^#, Xuejing Cui, Jing Liu, Luhua Jiang*

Nanomaterials and Electrocatalysis Laboratory, College of Materials Science & Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong, China

*Corresponding author: luhuajiang@qust.edu.cn (L. Jiang).

^# These authors contribute equally to this work.

Abstract:

Methanol electro-oxidation (MOR), as the anodic reaction of direct methanol fuel cells (DMFCs), is sluggish in kinetics, which limits the fuel cell performance seriously. Coupling electrocatalysis with photocatalysis is possibly to promote the MOR kinetics, yet is challengeable due to lack of well-designed photoelectrocatalysts and poor understanding in photo-electro-catalysis coupling mechanism. Herein, a photo-induced strategy is for the first time reported to generate Pt/BiVO₄/Bi₂O₃ hetero-structures, which display a superior photo-electro-catalytic activity for the MOR under irradiation. The in-situ generated Pt/BiVO₄/Bi₂O₃ hetero-structures is efficient for photogenerated charge separation and transfer, taking advantages of both tailored band structures and compatible interfaces. Mechanism study discovers that the kinetics of methanol dehydrogenation on Pt is promoted by the photogenerated OH_ad on BiVO₄/Bi₂O₃ heterojunction, leading to a CO_ad poison free pathway. This work provides a new photo-induced strategy to synthesize hetero-structured catalysts, and most importantly, the identification of the MOR pathway sheds lights on the underlying photo-electro-catalysis coupling mechanism, paving an avenue for construction of high performance DMFCs.

Keywords: Photo-induced strategy; Pt/BiVO₄/Bi₂O₃ hetero-structure; methanol oxidation; photo-electro-catalysis; coupling mechanism.

https://doi.org/10.1021/acssuschemeng.1c00764