All-in-one photocatalysis device for one-step high concentration H2O2 photoproduction

Achieving multi-functions integrating reaction, separation and concentration into one-step catalysis process is a great challenge. Photocatalytic H2O2 generation is the cleanest and cheapest way for its production. Herein, an all-in-one photocatalytic device for H2O2 generation was designed by catalysis layer with ZIF-8/C3N4 composite and carbon dots-based evaporation layer (CDE). With this device, H2O2 solution with high concentration is obtained, and no need for extra separation and concentration processes. Under 2 sun illumination (3 h), H2O2 evolution reaches 17.13 μmol and H2O2 solution concentration gets to 10.15 mmol L−1. Mole fraction of H2O2 solution obtained by all-in-one device is 1.86 times more concentrated than that of not concentrated H2O2 solution. Besides, multiples devices can work concurrently to realize large-scale production and gain large amounts of H2O2 solution with high concentration. Moreover, all-in-one devices can be reused at least ten cycles. The relation between the structure and performance of the photocatalysis device is further studied by COMSOL Multiphysics software and mathematical analysis. All-in-one photocatalytic device promotes H2O2 photoproduction closer to the practical application due to realizing continuous production of amounts of aqueous solution of H2O2 with high concentration in one-step.