Coupling charge dynamics with localized photothermal effects in Pt/WO3 for efficient solar-driven CO2 reduction

Multicarbon fuel synthesis achieved via photothermal-photocatalytic coupling. • Localized thermal flux synergizes with charge dynamics to accelerate surface kinetics. • Pt loading minimizes carrier recombination and maximizes solar-to-chemical efficiency. The integration of photothermal and photocatalytic processes presents a promising pathway to boost solar-driven CO 2 conversion, yet achieving efficient photo–heat synergy under concentrated sunlight remains challenging. Here, we report a Pt-nanoparticle-decorated WO 3 catalyst fabricated via chemical reduction, which demonstrates exceptional activity for CO 2 reduction under concentrated solar irradiation. The optimized 0.8Pt/WO 3 catalyst achieves CO, CH 4 , and C 2 H 4 production rates of 4.12, 2.12, and 0.63 μmol·h −1 ·g −1 , respectively, with a noteworthy 25.8- and 28.3-fold enhancement in CO and CH 4 yields upon switching from unconcentrated to concentrated light. Systematic characterization reveals that Pt nanoparticles not only act as electron sinks to facilitate charge separation and interfacial transfer, but also enhance visible-light absorption and photothermal conversion. Under concentrated irradiation, the coupled photothermal effect elevates the local temperature to ∼405 °C, promotes high-density carrier accumulation, and significantly lowers the apparent activation energy from 21.21 to 13.80 kJ·mol −1 . This work elucidates a synergistic photothermal–photocatalytic mechanism where enhanced charge dynamics and localized heating jointly drive efficient CO 2 valorization, offering a design blueprint for high-performance solar fuel catalysts.