A sol–gel technique was used to synthesize silver-doped antimony trioxide nanocomposites. Antimony trioxide and silver-doped antimony trioxide samples were characterized by multiple techniques. The TEM images reveal that antimony trioxide and silver-doped antimony trioxide nanocomposites
have nanoparticle shapes. Antimony trioxide has a wide band gap that can be controlled by the doping of silver, and the content of doped silver plays a vital role controlling the band gap energy. The photocatalytic performance of antimony trioxide and silver-doped antimony trioxide nanocomposites
was investigated via aniline preparation from the photocatalytic reduction of nitrobenzene. The XPS results reveal that the silver is found in the metallic silver state. Silver doping improves the photocatalytic activity of antimony trioxide for the preparation of aniline. This effect can
be ascribed to the narrowing of the band gap and the elongation of the lifetime for electron–hole recombination of antimony trioxide photocatalyst by silver doping. Thus, a photocatalyst with improved photocatalytic activity, limited band gap and improved e–h recombination
rate was synthesized by a facile sol–gel process method.