Photocatalyst-enzyme hybrid anode enhanced glucose deep oxidation for bioelectricity generation under visible light

Enzymatic biofuel cells (EBFC) show significant advantages in directly converting chemical energy (e.g., sugars) into electricity through redox reactions. However, a current challenge is how to deeply oxidize substrate (e.g., glucose) to enhance the performance of EBFC. Here, we propose a novel EBFC with BiVO₄-ZnO- ZIF-67 and GOx hybrid anode for achieving glucose deep oxidation to formate. The BiVO₄-ZnO-ZIF-67 enhances the intensity of light absorption and the ability of electron-hole separation, and enzyme loading is boosted by 3.9 times, thus the oxidation rate of glucose and the deep oxidation rate of produced gluconic acid are both enhanced. The corresponding maximum power density reaches 85.1 μW cm⁻², which is 28 times higher than that of the unmodified electrode. In 6h of darkness and then continuous light, the maximum power density can be further improved to 97.3 μW cm⁻². This work provides a novel strategy for high-efficiency substrate utilization to enhance EBFC performance by binding enzyme and photocatalyst.