Effects of fluorine modification on the photocatalytic hydrogen production performance of TiO2.

As an efficient and environmentally friendly photocatalyst, TiO₂ has garnered significant interest among researchers. However, the rapid recombination of photogenerated carriers leads to the inhibition of its photocatalytic activity. Fluorine modification has been proven to be an effective method to improve the photocatalytic performance of TiO₂, leading to a multitude of research reports on this subject. Surface fluorine adsorption or lattice fluorine doping can deftly modulate the surface chemical attributes and electronic configuration of the TiO₂ photocatalyst, thereby amplifying its functional performance. The role of fluorine atoms coordinated with different number titanium atoms (terminal Ti₁-F, bridging Ti₂-F and Ti₃-F) are also discussed. This paper provides a minireview of various aspects of fluorine-modified TiO₂, including its classification (surface-adsorbed fluorination, lattice-doped fluorination and Ti_x-F) and characterization techniques (X-ray photoelectron spectroscopy and solid-state nuclear magnetic resonance). Finally, this treatise elucidates the mechanistic impact of fluorine modification on the photocatalytic hydrogen production performance of TiO₂.