Bifunctional bio-photoelectrochemical cells: a “trading” platform for simultaneous production of electric power and hydrogen peroxide

Abstract

Inspired by natural photosynthesis, bio-photoelectrochemical (BPEC) cells based on photo-enzyme coupled catalysis hold great promise for energy conversion and chemical valorization. Here, we report an integrated BPEC system comprising a glucose dehydrogenase (GDH) modified meso-tetrakis(4-carboxyphenyl)-porphyrin/titanium dioxide (TCPP/TiO₂) dye-sensitized photoanode and a mesoporous carbon hollow spheres/carbon paper (MCHS/CP) cathode for light-driven glucose oxidation and hydrogen peroxide (H₂O₂) production, respectively. Such a proposed bifunctional BPEC cell delivers a maximum power output of 0.24 ± 0.03 mW cm⁻² with an open circuit voltage of 0.76 ± 0.01 V and achieves efficient H₂O₂ accumulation (rate: 0.94 ± 0.02 mM cm⁻² h⁻¹). Overall, our proof-of-concept assembly leverages the ascendancy of biocatalysis, photoelectrocatalysis, and electrosynthesis to provide an optimized design for biotic/abiotic coupling and expand the functional versatility of green energy devices.