Research advances in the second generation of visible-light photocatalysts of nonmetal-doped TiO_2

The development of low-cost,environment-friendly second generation of photocatalyst with a high activity under visible light irradiation is a vital trend for the further practicability of photocatalysis.Titanium dioxide doped with nitrogen is a novel second generation of photocatalyst with visible light photocatalytic activity,the width of forbidden band of composite photocatalysts doped with nonmetal is less than that of TiO_2,which makes the absorption of TiO_2 move toward visible light.The research progress in visible-light photocatalysis of titanium dioxide doped with nitrogen,carbon,sulfur and halogen was reviewed,and the factors improving the visible light photocatalytic activity are analyzed.The anion doping using nonmetal,especially nitrogen,is thought as a promising method to realize the response of TiO_2 to visible light on the basis of maintaining violet light photocatalytic activity.