Addressing the dual challenges of freshwater scarcity and pollution elimination requires innovative technologies that rationally integrate multiple functions. This study developed a representative dual-functional solar evaporator by coupling photothermal Fe₃O₄ nanospheres with oxygen-doped CdS (CdS-O) within a sponge-based hydrogel matrix, achieving concurrent high-efficiency solar-driven water regeneration and pollutant degradation. The design leverages the unique roles of two unique components, wherein, Fe₃O₄ endows the evaporator with broadband solar absorption (300–800 nm) and an superior photothermal conversion efficiency of 80 %, while oxygen doping CdS-O narrows its bandgap (from 2.31 eV to 2.29 eV), enhancing visible-light harvesting and charge separation. Crucially, the synergistic interplay between Fe₃O₄ and CdS-O establishes a self-sustained photo-Fenton-like mechanism. CdS-O generates H₂O₂ via photogenerated electron reduction of O₂, and Fe₃O₄ acts as an electron acceptor to accelerate Fe 3 + /Fe 2+ cycling, Fe²⁺ ions react with H₂O₂ via a Fenton-like process to produce ·OH radicals for pollutant mineralization. Simultaneously, the hydrogel-sponge architecture ensures rapid water transport and localized heat confinement, enabling an evaporation rate of 1.55 kg·m −2 ·h −1 under 1 sun irradiation. The system demonstrates remarkable dual-functionality: 86.9 % tetracycline degradation in lake water within 240 minutes and 89 % photocatalytic activity retention after six cycles. This work overcomes the limitations of conventional single-function systems by unifying photothermal evaporation and photocatalytic oxidation into a scalable platform, offering a sustainable solution for simultaneous water production and purification through material synergy and energy-efficient design.
Synergistic strain/phase engineering boosts photocatalytic hydrogen evolution performance. • The CdS-O/MS-5 achieves a high hydrogen evolution rate of 68.71 mmol·g −1 ·h −1 and AQE of 48.49%. • Strain-enhanced charge transfer couples with metallic/semiconducting phase junctions. While high-efficiency photocatalytic water splitting is pivotal for a sustainable hydrogen economy, its widespread implementation is hindered by sluggish charge-carrier kinetics and the formidable overpotentials inherent to traditional semiconductor. Here, we report a dual-optimization strategy to transcend these limitations by integrating oxygen-doped CdS (O-CdS) with a 1 T/2H-MoS 2 phase-engineered co-catalyst. The interstitial incorporation of oxygen induces a pronounced lattice expansion within the CdS framework, which reconfigures the electronic band structure by introducing additional electronic states near the Fermi level. These emergent states act as energetic stepping stones, facilitating efficient charge injection into the co-catalyst. Concurrently, the rational design of the 1 T/2H-MoS 2 metallic/semiconducting homojunction facilitates efficient interfacial charge extraction and provides abundant active sites for proton reduction. This synergistic integration of lattice-strain engineering and phase-controlled co-catalytic architectures simultaneously elevates photocatalytic activity and long-term durability. The optimized system exhibits a 2.5-fold enhancement in hydrogen evolution performance (68.71 mmol g −1 h −1 ) over the pristine CdS. Our findings establish a robust paradigm for leveraging lattice distortion and polymorphic phase engineering to optimize solar-to-chemical energy conversion in hybrid semiconductor architectures.