Synthesis, characterization and silver/copper-nitrogen substitutional effect on visible light driven photocatalytic performance of sodium hexatitanate nanostructures

BACKGROUND The large‐scale organic pollutants discharged from various industries tend to persist in aquatic habitats and pose a serious threat to ecological and human health. Photocatalysis has proven to be an efficient tool to detoxify such contaminants present in water. For effective utilization of abundant and untapped sunlight, a photocatalyst should possess good visible light response. In addition, an efficient catalyst should restrain the recombination of e−/h+ pairs. In this context, a series of visible light driven photocatalysts were prepared by substituting both cation (Cu2+/Ag+) and anion (N3−) into Na2Ti6O13 (NTO) by simple ion exchange and solid state methods, respectively. RESULTS The as‐prepared catalysts retained the skeleton structure of parent NTO. The bandgap energies of all catalysts ranged from 3.67 to 2.51 eV. Photocatalytic activity of all samples was evaluated by studying the degradation of methyl orange (MO) and 4‐chlorophenol (4CP) under visible light irradiation. The best activity was observed for silver/nitrogen co‐doped NTO against both MO and 4CP. CONCLUSION The superior activity of silver/nitrogen co‐doped NTO is ascribed to its narrow bandgap energy, higher surface area and lower rate of recombination of charge carriers. This study demonstrates the efficient pathway of cation/anion doping to improve the photocatalytic performance of Na2Ti6O13. © 2014 Society of Chemical Industry