Photocatalytic H2O2 production from resorcinol-formaldehyde resin spheres with anthraquinone structure

The production of hydrogen peroxide (H2O2) by photocatalytic oxygen reduction reaction (ORR) without sacrificial agents is a green method of great significance, in which the design of high-performance photocatalysts is its central task. This study reports a molecular-level structure design to introduce anthraquinone structure into the resin backbone through Schiff base reaction. In this design, 1,5-diaminoanthraquinone undergoes a Schiff base reaction with aldehyde groups through acid catalysis and is incorporated into the resin backbone (RF-DAAQ). The introduction of the carbonyl group in anthraquinone adjusts the ratio of D-A pairs in the resin, speeds up the separation speed of photogenerated electron holes, and makes it easier to absorb oxygen, further convert it into its intermediate product, and finally generate H2O2. The mechanism was explored by various characterization methods such as in situ diffuse reflectance fourier transform infrared spectroscopy (in situ DRIFTS) and DFT calculations. The RF-DAAQ-4 photocatalyst exhibits a H2O2 yield of 640.91 μM g-1h−1, which is 6 times higher than that of pristine RF and also shows a competitive advantage in many reported photocatalysts under similar reaction conditions. This work paves the way for designing molecular level catalyst for green synthetic H2O2 production.