关键词: 光催化, 罗丹明B, 异质结, 降解机制

Abstract: In view of the low catalytic activity of titanate nanotubes photocatalyst (TNTs), photocatalyst of TNTs loaded with active component Ag was prepared by in-situ photoreduction-deposition method, aiming to enhance the photoresponse ability and reduce the electron-hole recombination rate by taking advantage of the plasma resonance effect of precious metals. Rhodamine B was completely removed by 10% Ag/TNTs within 120 min. The degradation rate k fitted to the firstorder kinetics was 0.04227 min^-1, which was 2.3 times that of unloaded TNTs (0.01865 min^-1). UV-Vis calculations measured that the energy band gap width (3.1 eV) of 10% Ag/TNTs was also much narrower than unloaded TNTs (3.44 eV). Characterizations of TEM and XPS showed that Ag nanoparticles were successfully loaded on TNTs. The heterojunction facilitated the separation and migration of photogenerated electrons and holes, enhanced the surface electron capture ability, and improved photocatalytic activity.

Key words: photocatalysis, rhodamine B, heterojunction, degradation mechanism.