Plasmon-Driven Reaction Selectivity Tuning for Photoelectrochemical H<sub>2</sub>O<sub>2</sub> Production
Gyu Yong Jang, Young Moon Choi, Seung Hun Roh, Shipeng Wan, Kan Zhang, Seok Joon Kwon, Jung Kyu Kim, Jong Hyeok Park
Abstract
Photoelectrochemical (PEC) H 2 O 2 production has gained interest as a green, promising route to produce valuable chemicals. However, it suffers from low H 2 O 2 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 BiVO 4 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 H 2 O 2 . As a result, BiVO 4 /Au-PAT achieves a H 2 O 2 Faradaic efficiency approximately 3.3 times higher than that of pristine BiVO 4 . 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.