Artificial photosynthesis of hydrogen peroxide in neutral water is limited by weak solar absorption and the lack of interfaces that selectively channel electrons into the two-electron oxygen-reduction pathway. We address these constraints by co-engineering band structure and electron pathways through etching-assisted transformation of Prussian blue analogues into defect-rich metal-sulfide photocatalysts and integration of graphdiyne carbon cocatalysts. The sulfur-etching conversion yields defect-rich Zn-CdS with red-shifted absorption and favorable band energetics, while graphdiyne provides π-conjugated pathways and sites that stabilize *OOH, directing two-electron reduction of O2 to H2O2. Energetic alignment from work-function/valence-band measurements and density-functional theory indicates downhill electron transfer from the sulfide to graphdiyne, corroborated by photoluminescence quenching, shorter lifetimes, lower charge-transfer resistance, and higher photocurrent. In situ diffuse-reflectance infrared spectroscopy detects *OOH/ H2O2, spin-trapping electron-paramagnetic resonance confirms oxygenated intermediates, and rotating ring-disk voltammetry indicates a near-two-electron pathway. Under UV-vis irradiation, the composite exhibits a H2O2 formation rate of 128.7 µmol g- 1 min- 1 without sacrificial agents, maintains activity over cycling, and permits kinetic deconvolution of formation versus self-decomposition. Extending the method to Ni/Mn/Co precursors reproduces the structure-function trend. By coupling light-harvesting control with interfacial catalytic specificity, this organic-inorganic heterojunction offers a route to efficient, sacrificial-agent-free photosynthesis of H2O2.
Zhang et al. (Sun,) studied this question.