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

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.