CuO/Cu(OH)₂@g-C₃N₄ derived from CuBTC/g-C₃N₄ for two channel photocatalytic hydrogen peroxide production

Photocatalytic production of H₂O₂ is indeed a safe, sustainable and cost-effective technology, offering an environmentally friendly solution to the energy crisis through solar photocatalysis. However, it still faces challenges such as reliance on organic electron donors and pure O₂, as well as inefficiencies in hole utilization. To overcome these limitations, a dual-channel photocatalytic system has been developed. In this study, we showcase the efficiency of the CuO/Cu(OH)₂@g-C₃N₄ composite, derived from CuBTC/g-C₃N₄ via NaOH treatment, as a high-performance dual-channel photocatalyst for H₂O₂ production. Under visible light (λ ≥ 420 nm), this composite achieves a H₂O₂ yield of 1354 μmol/L in 120 min without any sacrificial agent, outperforming g-C₃N₄ by 8.4 times, CuO by 13.6 times and CuO@g-C₃N₄ by 1.9 times. Quenching experiments and electron paramagnetic resonance spectra confirmed that HO^• and O₂^•- are intermediate products in the photocatalytic process, following a two-step single-electron reaction pathway. The superior activity of CuO/Cu(OH)₂@g-C₃N₄ in H₂O₂ generation can be attributed to the synergistic effects of OH bonds on the CuO@g-C₃N₄ Z-type heterojunction and Cu(OH)₂. This research presents a straightforward and promising approach for developing highly efficient photocatalysts for energy conversion.