Photothermal catalytic C–C coupling to ethylene from CO2 with high efficiency by synergistic cooperation of oxygen vacancy and half-metallic WTe2

Abstract

Photothermal catalytic CO2 conversion provides an effective solution targeting carbon neutrality by synergistic utilization of photon and heat. However, the C–C coupling initiated by photothermal catalysis is still a big challenge. Herein, a three-dimensional (3D) hierarchical W18O49/WTe2 hollow nanosphere is constructed through in-situ embodying of oxygen vacancy and tellurium on the scaffold of WO3. The light absorption towards near-infrared spectral region and CO2 adsorption are enhanced by the formation of half-metal WTe2 and the unique hierarchical hollow architecture. Combining with the generation of oxygen vacancy with strengthened CO2 capture, the photothermal effect on the samples can be sufficiently exploited for activating the CO2 molecules. In particular, the close contact between W18O49 and WTe2 largely promotes the photoinduced charge separation and mass transfer, and thus the *CHO intermediate formation and fixedness are facilitated. As a result, the C–C coupling can be evoked between tungsten and tellurium atoms on WTe2. The ethylene production by optimized W18O49/WTe2 reaches 147.6 μmol g−1 with the selectivity of 80%. The in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations are performed to unveil the presence and significance of aldehyde intermediate groups in C–C coupling. The half-metallic WTe2 cocatalyst proposes a new approach for efficient CO2 conversion with solar energy, and may especially create a new platform for the generation of multi-carbon products.