Photocatalytic CO2 Reduction over Cotton-like Blue C/TiO2 Nanotubes: Enhanced Performance via Structural Engineering.

Photocatalytic reduction of carbon dioxide is a very effective strategy to address the energy crisis and greenhouse effect. TiO2 is a widely used semiconductor photocatalyst, which has excellent catalytic activity, excellent chemical stability and low toxicity. Nevertheless, TiO2 still has some inherent limitations, such as: wide band gap, high carrier recombination rate, and low adsorption activation ability for carbon dioxide. These drawbacks severely restrict its further application in the photocatalytic reduction of CO2. In this study, cotton-like blue C/TiO2 NTs are successfully synthesized through the in situ growth of TiO2 nanotubes on the MIL-125(Ti)-derived C/TiO2 precursor. The experimental results revealed that the CO production rate of the cotton-like blue C/TiO2 NTs was 1.84 times that of C/TiO2 and 3.78 times that of TiO2 nanotubes. These results clearly demonstrate that the cotton-like blue C/TiO2 NTs exhibit a broad spectral response, a large specific surface area, and an abundance of oxygen vacancies. This research provides new insights into the design of titanium dioxide-based photocatalytic materials and opens up a promising avenue for enhancing the performance of titanium dioxide in the photocatalytic reduction of carbon dioxide.