Efficient CO release from plasmonic Pt using 1D BiVO4@TiO2 heterojunctions for improved electrocatalytic and photoelectrocatalytic methanol oxidation

Abstract

The synergistic combination of 1D TiO₂ nanorods and BiVO₄ results in compatible electronic band structure alignment at their interfaces to ensure enhanced photoactivated charge separation and transportation under visible light irradiation. Herein, the plasmonic effect of platinum on 1D BiVO₄/TiO₂ nanorods was explored to establish charge transfer at the heterojunctions and improve the activities of methanol oxidation. Structural, compositional, morphological and electrochemical performance was explored. Noticeably, 10-Pt/BiVO₄/TiO₂ showed an excellent current density of 64.6 mA cm⁻² under 100 mW cm⁻² illumination as compared to 12.5 mA cm⁻² under dark conditions. Moreover, the highest lifetime of 227.3 ms under light was observed as compared to 63.6 ms under dark conditions. Moreover, electrochemical impedance spectroscopy (EIS) studies of 10-Pt/BiVO₄/TiO₂ showed the least charge transfer resistance (R_ct) of 161 Ω under one sun light in comparison to 385 Ω under dark conditions. Moreover, the methanol oxidation reaction (MOR) efficiency for 5, 10 and 15 cycles of Pt over BiVO₄/TiO₂ was found to be 335%, 417% and 78%, respectively. The surface plasmon resonance (SPR) property of Pt was enhanced with the substrate of the 1D BiVO₄/TiO₂ heterojunction, and this strategy showed its unprecedented potential to be utilized for electrocatalytic and photo-electrocatalytic applications.