Photocatalytic H ₂ O ₂ Synthesis at NiS/NiSe-Coated Nanoporous Poly(dimethylsiloxane) Membrane Triphase Interfaces

High Resolution Image Download MS PowerPoint Slide Photocatalytic hydrogen peroxide (H 2 O 2 ) production offers a sustainable alternative, though it faces challenges such as low oxygen (O 2 ) diffusion in the electrolyte and high electron–hole recombination rates. This study introduces an air–liquid–solid triphase reaction interface using a nickel sulfide/nickel selenide (NiS/NiSe) photocatalyst on a nanoporous hydrophobic poly(dimethylsiloxane) (PDMS) membrane, enhancing O 2 accessibility and catalytic efficiency. The triphase system generates 1041.2 μmol g –1 h –1 H 2 O 2 without an external O 2 supply, significantly outperforming the conventional diphase system, which produces 286 μmol g –1 h –1 with a constant external O 2 supply. This enhancement is due to the synergy between (i) the nanoporous hydrophobic PDMS membrane, which enables continuous O 2 diffusion to the catalyst surface, and (ii) the NiS/NiSe S-scheme heterojunction, which promotes charge separation. The mechanistic aspects and reaction pathway for H 2 O 2 production are elaborated in the study using electrochemical techniques.