Tailoring well-ordered, highly crystalline carbon nitride nanoarrays via molecular engineering for efficient photosynthesis of H2O2

Small-scale on -site artificial photosynthesis of H 2 O 2 from O 2 and H 2 O is an ideal sustainable route. In particularly, g-C 3 N 4 is a very popular catalyst, nevertheless, its photocatalytic activity is severely inhibited by the random migration and rapid recombination of photogenerated carriers. Herein, a well-ordered highly-crystalline g-C 3 N 4 nanoarray with conjugated electron donor-acceptor structure (denoted as PDI/CNA) is rationally designed for efficient H 2 O 2 production to imitate the photosynthesis of natural plants. Both experimental and DFT investigations demonstrate that the tailored PDI/CNA effectively improve charges utilization via eliminating deep defect trapping sites, and reduce its Gibbs free energy (ΔG) of rate-determining step (*HOOH→H 2 O 2 ). As a result, the optimized PDI/CNA exhibits a superior H 2 O 2 production rate of 1605.32 μmol g −1 h −1 and a high apparent quantum yield of 27.18% (λ = 400 nm). This work sheds light on promoting H 2 O 2 photosynthesis by regulating the crystalline structure of g-C 3 N 4 and rationally designing spatially separated redox centers. • Photosynthesis of H 2 O 2 on -site production via 2e - oxygen reduction reaction. • Well-ordered highly-crystalline g-C 3 N 4 nanoarray for efficient charges utilization. • Conjugated electron donor-acceptor structure for spatially separated redox centers. • Reduced Gibbs free energy (ΔG) of rate-determining step (*HOOH→H 2 O 2 ). • Superior H 2 O 2 production rate of 1605.32 μmol g −1 h −1 and AQY of 27.18% (λ = 400 nm).