Polydopamine-sheathed Cu2O supraparticles for improved photocatalytic H2O2 production via a scalable one-pot synthesis

To achieve stable and efficient photocatalytic production of hydrogen peroxide (H 2 O 2 ), this study presents a composite photocatalyst where a polydopamine (PDA) layer was formed on cuprous oxide (Cu 2 O) supraparticles via a straightforward self-polymerization of dopamine. By maintaining a constant amount of Cu 2 O and tuning the PDA concentration, the optimal formulation exhibiting the highest H 2 O 2 yield was identified. Structural and chemical analyses confirmed the uniform PDA coating and demonstrated that the composite effectively suppressed H 2 O 2 decomposition and maintained excellent stability over repeated cycles. This enhanced performance is attributed to improved charge transfer pathways between Cu 2 O and PDA. The band structure and electron transfer analysis further revealed that the composite follows a p-n type-Ⅱ heterojunction mechanism, enabling selective H 2 O 2 generation via the two-electron oxygen reduction reaction (ORR). We expect that this simple one-pot approach to constructing high-efficiency, scalable, and stable photocatalysts will offer new opportunities for green energy conversion and environmental remediation.