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

Photocatalytic production of HO 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 O, 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)@g-CN composite, derived from CuBTC/g-CN via NaOH treatment, as a high-performance dual-channel photocatalyst for HO production. Under visible light (λ ≥ 420 nm), this composite achieves a HO yield of 1354 μmol/L in 120 min without any sacrificial agent, outperforming g-CN by 8.4 times, CuO by 13.6 times and CuO@g-CN by 1.9 times. Quenching experiments and electron paramagnetic resonance spectra confirmed that HO and O are intermediate products in the photocatalytic process, following a two-step single-electron reaction pathway. The superior activity of CuO/Cu(OH)@g-CN in HO generation can be attributed to the synergistic effects of OH bonds on the CuO@g-CN Z-type heterojunction and Cu(OH). This research presents a straightforward and promising approach for developing highly efficient photocatalysts for energy conversion.