Photocatalytic H2O2 and H2 Generation from Living Chlorella vulgaris and Carbon Micro Particle Comodified g-C3N4

Hydrogen production from water splitting using photocatalysts and solar energy is an ideal pathway to obtain future energy sources which are cheap and easy to industrialize. In the water splitting process, the reduction of H2O gives H-2, while H2O oxidation produces O-2 with hydrogen peroxide (H2O2) in tiny amounts as a by-product (poisoning the catalyst). It remains challenging to simultaneously produce H2O2 and H-2 within one photocatalytic system. Inspired by a biological H2O2 generator, chlorella, the authors firstly realize the simultaneous photocatalytic water splitting and biological H2O2 generation by a living Chlorella vulgaris and carbon micro particle (needle coke) comodified g-C3N4 (C-N-g-C3N4) photocatalyst. The C-N-g-C3N4 exhibits the optimal H2O2 (H-2) evolution rate of 0.98 mu mol h(-1) (0.84 mu mol h(-1)), giving an apparent quantum efficiency of 0.86% for H-2 evolution at 420 nm. In this system, the needle coke serves as cocatalyst to work as reduction sites for H-2 evolution, while the living C. vulgaris plays the key role in the production of H2O2 under the protection of g-C3N4.