Urchinlike W18O49/g-C3N4 Z-Scheme Heterojunction for Highly Efficient Photocatalytic Reduction of CO2 under Full Spectrum Light

In this work, an urchinlike W18O49/g-C3N4 composite was fabricated via a simple hydrothermal process. The photocatalytic CO2 conversion reaction was applied to evaluate the photocatalytic behavior of this catalytic system, and the WOCN-20 wt % heterojunction displayed superior photocatalytic behavior under full spectrum light irradiation, which was 6.46 μmol·h–1·g–1 for CO and 3.97 μmol·h–1·g–1 for CH4, respectively. Furthermore, in the near-infrared region, the composite photocatalysts also displayed excellent photocatalytic performance. A large number of characterizations and testing measures were carried out to study the components, morphology, and physicochemical properties of W18O49/g-C3N4 photocatalyst, which were helpful to exploring and understanding the reasons for the improvement of catalytic performance. The boosted activity resulted from the tight contact between W18O49 and g-C3N4 and the formation of a Z-scheme heterojunction. The local surface plasmonic resonance (LSPR) of W5+ also contributed to the realization of efficient photocatalysis under near-infrared light. The Z-scheme electron transport model could realize the efficient separation of light-induced e––h+ pairs and reduce the recombination rate, thereby boosting the CO2 photocatalytic reduction process.