Energy-efficient photodegradation of azo dyes with TiO(2) nanoparticles based on photoisomerization and alternate UV-visible light.

Herein, we demonstrated a UV-vis light alternate photocatalysis (UVLAP) strategy in the photodegradation of azo dyes. The UVLAP of azo dyes over TiO(2) catalysts exhibited significantly higher energy efficiency than the conventional UV process by 40%, which was attributed to the photoisomerization of azo dyes and the resulting diversity of dyes' cis and trans states in interfacial properties, including conductance and spatial effects. This UVLAP strategy could contribute to the energy-saving photodegradation of azo dyes and other pollutants with photoisomerization properties and facilitate the practical application of TiO(2) in the environmental remediation.