Plasmon-Driven Reaction Selectivity Tuning for Photoelectrochemical H2O2 Production

Photoelectrochemical (PEC) H2O2 production has gained interest as a green, promising route to produce valuable chemicals. However, it suffers from low H2O2 Faradaic efficiency due to competing O-2 generation. Here, we propose a plasmon-driven band structure engineering strategy to thermodynamically regulate the product selectivity of a metal oxide based PEC photoanode. It is demonstrated that the plasmonic near-field generated by the periodically patterned Au nanosphere arrays (Au-PAT) effectively modulates the surface photovoltage and energy band structure of the BiVO4 photoanode. This modulation helps photoinduced charge carriers to satisfy the thermodynamic potential required to shift the water oxidation reaction (WOR) product from O-2 to high-value H2O2. As a result, BiVO4/Au-PAT achieves a H2O2 Faradaic efficiency approximately 3.3 times higher than that of pristine BiVO4. These findings suggest the effectiveness of external modulation, originating from a plasmonic near-field effect, in regulating the WOR pathway, providing an efficient and selective route to value-added PEC production.

Automated summary

In this study, a plasmon-driven strategy was proposed to regulate the product selectivity of a metal oxide-based photoelectrochemical photoanode. By modulating the surface photovoltage and energy band structure of the photoanode, the plasmonic near-field effect enabled the photoinduced charge carriers to meet the thermodynamic potential required for the conversion of water oxidation reaction (WOR) from O-2 to high-value H2O2. As a result, the H2O2 Faradaic efficiency of BiVO4/Au-PAT was approximately 3.3 times higher than that of pristine BiVO4.