In Situ Fabrication of C/TiO₂ Photothermal Catalytic Materials for Hydrogen Production and Pollutant Degradation

Photocatalysis is regarded as one of the most promising methods to alleviate energy shortages and environmental pollution. However, most traditional photocatalysts fail to utilize the infrared region of solar energy, limiting the energy conversion efficiency. To address this issue, coupling photocatalysis with the photothermal effect offers a promising solution to broaden the light response range, realize full-spectrum solar utilization, and further boost catalytic kinetics by leveraging photogenerated heat. In this work, C/TiO₂ was synthesized by in situ conversion of Ti-based MOF (MIL-125) under an argon atmosphere. The photothermal catalytic hydrogen production and R6G degradation efficiencies of C/TiO₂ were 5.89-fold and 1.76-fold enhancements, respectively, relative to the sum of its individual photocatalytic and thermocatalytic efficiencies. Notably, the apparent quantum yield of C/TiO₂ for photothermal catalytic hydrogen production reached 86.1% at 350 nm and 95.0°C, far exceeding that of TiO₂ (18.2%, measured at the same wavelength at 88.7°C). The enhanced performance of C/TiO₂ originates from the in situ-formed carbon layer, which maintains intimate contact with the TiO₂ surface. This structure facilitates rapid migration of photogenerated electrons and elevates the reaction temperature via efficient infrared light absorption and photothermal conversion. This work provides a novel strategy for designing a low-cost, self-heating photothermal catalytic system for efficient hydrogen production and pollutant degradation.