Near-Infrared Photothermal Activation in WO3–x Hollow Spheres for Boosted Photocatalysis

Conventional photocatalysts face limitations in solar energy absorption and photocatalytic efficiency, hindering their practical applications in energy conversion and environmental remediation. Given that heat is a general promoter of catalytic reaction activity, we here developed hydrogenated hollow mesoporous WO3 spheres (WO3–x) as dual-functional photocatalysts. They can utilize ultraviolet–visible light for direct photocatalysis, while simultaneously harnessing the remaining near-infrared portion of the solar spectrum to achieve photothermal enhancement. Due to the photothermally improved activation of reactants and accelerated reaction kinetics, the developed WO3–x exhibited a 3-fold increase in CH4 production with 96% selectivity in CO2 photoreduction and a 10-fold enhancement in toluene degradation under full-spectrum irradiation, compared to pristine WO3. Moreover, even after 100 days of storage in air, WO3–x retained its excellent near-infrared photothermal conversion ability and sustained enhancement of reaction activity. These findings highlight the significant potential of photothermal catalysis for efficient solar energy utilization, further driving the development of near-infrared photothermal conversion materials and their application in sustainable energy conversion and environmental remediation.