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 (Cu 2+ /Ag + ) and anion ( N 3 − ) into Na 2 Ti 6 O 13 ( NTO ) by simple ion exchange and solid state methods, respectively. RESULTS The as‐prepared catalysts retained t he 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 Na 2 Ti 6 O 13 . © 2014 Society of Chemical Industry