Ambient Preparation of Benzoxazine‐based Phenolic Resins Enables Long‐term Sustainable Photosynthesis of Hydrogen Peroxide

Abstract

Rational design of polymer structures at the molecular level promotes the iteration of high‐performance photocatalyst for sustainable photocatalytic hydrogen peroxide (H2O2) production from oxygen and water, which also lays the basis for revealing the reaction mechanism. Here we report a benzoxazine‐based m‐aminophenol‐formaldehyde resin (APFac) polymerized at ambient conditions, exhibiting superior H2O2 yield and long‐term stability to most polymeric photocatalysts. Benzoxazine structure was identified as the crucial photocatalytic active segment in APFac. Favorable adsorption of oxygen/intermediates on benzoxazine structure and commendable product selectivity accelerated the reaction kinetically in stepwise single‐electron oxygen reduction reaction. The proposed benzoxazine‐based phenolic resin provides the possibility of production in batches and industrial application, and sheds light on the de novo design and analysis of metal‐free polymeric photocatalysts.

Proton reservoirs in polymer photocatalysts for superior H2O2 photosynthesis

“…4b). 47,48 The formation of superoxide indicated the partial electron transfer between QAP 2 and O 2 . This partial electron transfer also led to the alternations in the electronic structures of QAP 2 and the strengthened internal charge separation in quinone-amine donor–acceptor pairs.…”

Clean Production of Hydrogen Peroxide: A Heterogeneous Solar‐Driven Redox Process

“…Although extensive efforts have been made to develop carbon-based and metal oxide materials, novel photoactive catalysts with special functions can play a determining role in promoting the catalytic performance further. Recently, a series of covalent organic frameworks, [221] resin, [222] halide perovskites, [223] and lignin, [224] have been synthesized for solardriven H 2 O 2 formation, thus paving the way for more efficient photocatalysis. Besides, novel technologies, such as piezo response, can be combined with photo(electro)catalysis to further improve H 2 O 2 production.…”

Synergistic Promotion of the Photocatalytic Preparation of Hydrogen Peroxide (H2O2) from Oxygen by Benzoxazine and Si─O─Ti Bond

“…The efficient preparation of H 2 O 2 through photocatalysis using nano-BZT catalyst, which is prepared through co-hydrolysis, can be attributed to two factors. First, the Si─O─Ti bond plays a significant role, and second, the benzoxazine [21] structure contributes to the catalyst's efficiency. This work mainly combines the Si─O─Ti bond and benzoxazine, and then synergistic promotion of the photocatalytic preparation of H 2 O 2 .…”

“…And then, after the preparation of H 2 O 2 , it returned to the benzoxazine structure. [21] The benzoxazine structure appears almost flat, but the nitrogen atom is positioned above the plane of the benzene ring, while the methylene carbon atom between the nitrogen and oxygen atoms is positioned below the ring. This arrangement, along with the presence of ring tension and external light stimulation, allows the ring's potential energy to convert light energy into photoelectron holes.…”

“…[19] The flexibility of organic polymers at the molecular level enhances their optoelectronic and surface catalytic properties, leading to improved reaction performance over time. [20] The pioneering work of Shiraishi et al opened up an avenue in exploring phenolic resin for photocatalytic H 2 O 2 production, and benzoxazine (as a special phenolic resin) for photocatalytic H 2 O 2 production by Jian Liu et al [7,21] Benzoxazine is a unique type of phenolic resin that offers the advantage of molecular design flexibility and the use of diverse raw materials. [22] The use of synthesized benzoxazine as a photocatalyst offers the benefits of a broad range of sources and convenient accessibility.…”