Rational Design of Photoanodes in Portable Devices to Enhance H ₂ O ₂ Production for Microenvironment Control

ABSTRACT Hydrogen peroxide (H ₂ O ₂ ) is a versatile oxidant with significant applications, particularly in regulating the microenvironment for healthcare purposes. Herein, a rational design of the photoanode is implemented to enhance H ₂ O ₂ production by oxidizing H ₂ O in a portable photoelectrocatalysis (PEC) device. The obtained solution from this system is demonstrated for effective bactericidal activity against Staphylococcus aureus and Escherichia coli , while maintaining low toxicity toward hippocampal neuronal cells. The photoanode is achieved by Mo‐doped BiVO ₄ films, which are subsequently loaded with cobalt‐porphyrin (Co‐py) molecules as a co‐catalyst. As a result, the optimal performance for H ₂ O ₂ production rate was achieved at 8.4 μmol h ⁻¹ cm ⁻² , which is 1.8 times that of the pristine BiVO ₄ photoanode. Density functional theory (DFT) simulations reveal that the improved performance results from a 1.1 eV reduction in the energy of the rate‐determining step of •OH adsorption by the optimal photoanode. This study demonstrates a PEC approach for promoting H ₂ O ₂ production by converting H ₂ O for antibacterial purposes, offering potential applications in conventionally controlling microenvironments for healthcare applications.