A comparison of N‐doped TiO 2 photocatalysts preparation methods and studies on their catalytic activity

Background N‐doped TiO 2 can narrow the TiO 2 forbidden band and thereby increase its catalytic activity under visible light. In this work, three methods (the sol–gel method ( SG ), the tetrabutyl titanate hydrolysis precipitation method TN ', and the H 2 O 2 ‐modified method ( TNH )) were used to prepare N‐doped TiO2 photocatalysts. The Reactive Red‐Violet dye ( KN ‐R) was used as the target pollutant. The catalytic activities of the photocatalysts prepared via the three methods were compared and studied . Results The structures and optoelectronic properties of these catalysts were characterized by various means. The results demonstrated that the N‐doped TiO 2 catalyst synthesized using the TNH method exhibited the most efficient catalytic activity under visible light and produced a degradation rate of 90% for the Reactive Red‐Violet dye. The N‐doped TiO 2 prepared using the SG method exhibited the lowest catalytic activity under both UV and visible light. The kinetics of photocatalysis degradation for KN ‐R by N‐doped TiO 2 prepared by TNH method was studied and found to be zero order due to the good adsorption effect between KN ‐R and TiO 2 . Conclusion The N‐doped TiO2 prepared by TNH method showed good photocatalytic activity in the case of degrading dye under both UV and visible light. © 2013 Society of Chemical Industry