Improved photocatalytic CO ₂ reduction performance of TiO ₂ /TiC(O) multilayer heterojunction induced by GO composite aerogel

Photocatalytic CO₂reduction (PCR) has attracted significant attention for its potential in addressing energy crisis and combating carbon pollution. However, developing efficient and stable photocatalytic systems remains a persistent challenge in this field. Among various materials, titanium carbide (TiC) and its derivatives have demonstrated excellent PCR performance, showing great promise for industrial applications. In this paper, oxygen-doped TiC multilayer nanosheets (TiC(O)) were prepared by a high-temperature carbon thermal reduction method, using TiO₂nanopowder and graphene oxide (n-TiO₂/GO) composite aerogels as raw materials. And then, the TiO₂/TiC(O) multilayer heterojunctions was constructed by in-situ annealing process.The characterization results of X-ray diffraction (XRD), UV-Vis, and X-ray photoelectron spectroscopy (XPS) demonstrated that n-TiO₂/GO composite aerogel could induce the growth of TiC(O) multilayer nanosheets with good PCR performance under high-temperature conditions. The TiO₂/TiC(O) multilayer heterojunction exhibited enhanced specific surface area, wider spectral response range, and higher photogenerated carrier separation efficiency, which promoted the PCR performance of the material. Under the irradiation of 150W Xenon lamp, the optimal sample TiO₂/TiC(O)-6 achieved a methane (CH₄) yield of 43.54 µmol·g^-1·h^-1, 2.55 times higher than that of the raw material TiC(O)-4.5 (17.08 µmol·g^-1·h^-1), and showed excellent cycling stability. This study offers a potential pathway to developing green, stable, and efficient photocatalysts for PCR applications.