Synergistic Sulfur Vacancy and Polydopamine Engineering in S v-CdS@PDA Z-scheme Heterojunctions for Photocatalytic H2O2 Production with Robust Anticorrosion

• • The Sv-CdS@PDA Z-scheme heterojunction achieves a photocatalytic H2O2 production rate of 4395.5 μmol g−1 h−1 under visible light, which is 15.6 times higher than pristine CdS, demonstrating a significant enhancement in solar-to-chemical conversion efficiency for industrial-scale H2O2 synthesis. • • Sulfur vacancy engineering reduces the work function of CdS, facilitating energy level alignment with PDA and enabling efficient electron transfer, as confirmed by XPS and DFT calculations; this mechanistic insight guides the design of high-efficiency sulfide-based photocatalysts. • • PDA encapsulation enhances O2 adsorption and provides robust anticorrosion protection, as evidenced by superior photostability of Sv-CdS@PDA compared to Sv-CdS after three consecutive photocatalytic cycles, addressing the critical stability bottleneck for long-term operation. • • The dual-functional strategy of Sv engineering and PDA coating synergistically improves charge separation and stability, achieving a H2O2 production rate of 2539.5 μmol g−1 h−1 for Sv-CdS alone, which is further boosted to 4395.5 μmol g−1 h−1 after PDA encapsulation, underscoring the importance of surface engineering in photocatalytic systems.