Photothermal-Photoelectric Synergistic Management in High-Entropy Alloys for Full-Spectrum Solar CO2-to-CH4 Conversion.

Current photothermocatalysts, characterized by inadequate photogenerated electrons for accelerating reaction kinetics as well as excessive demand for high light intensity, face major obstacles to practical application. In this study, a heteroarchitectured photothermocatalyst is presented by integrating the FeCoNiCuCr (FCNCuCr) high-entropy alloys (HEAs) photothermal layer, the Al doped ZnO (AZO) photoelectric layer, and the thermal radiation blocking component of chromium-plated glass (Cg). The obtained Cg/FCNCuCr/AZO photothermocatalyst exhibits an unprecedented CO2-to-CH4 conversion performance, with CH4 yield reaching 5082.9 µmol g-1 h-1, which is 14 and 4 times that obtained from pristine FCNCuCr HEAs and Cg/FCNCuCr, respectively, surpassing the state-of-the-art photothermocatalysts and photocatalysts for gas-solid atmospheric pressure CO2 conversion with H2O supplied as proton source. Thanks to effective photothermal management, the Cg/FCNCuCr/AZO heteroarchitectured photothermocatalyst achieves full-spectrum solar absorption by minimizing thermal radiation, thereby realizing excellent photothermal conversion capability. Meanwhile, the sputtered AZO photoelectric layer is integrated to establish an interfacial Schottky barrier, harnessing the photoelectric synergy, and further reducing the reaction barrier for CO2-to-CH4 conversion. The present photothermal-photoelectric synergistic management strategy enlightens the design of high-performance photothermocatalysts for solar driven CO2 conversion.