Superior sunlight photocatalytic of N/La codoped ZnO nanostructures synthesized using different chelating agents

Abstract

N/La codoped ZnO exhibited high sunlight activity, good reusability and rapid photodegradation for Congo red, malachite green and methylene blue dyes. Pure and N/La codoped ZnO were synthesized by sol gel using different chelating agents. All XRD patterns are fully indexed to hexagonal wurtzite structure of ZnO. The XRD peak shift and the increases in unit cell volume confirm the effective incorporation of N/La ions into ZnO. N/La blend extended the absorption ability of ZnO nanostructures to visible light region. Pure and N/La codoped ZnO synthesized by citric acid showed homogenous spherical nanoparticles distribution. Oxalic acid induced the formation of nanosheets and fine nanoparticles in N/La codoped ZnO. The adsorption capacity of pure and N/La codoped ZnO powders toward CR, MG and MB was less than 8%. The degradation of CR, MG and MB dyes under sunlight without catalyst is very weak. N/La codoped ZnO nanostructures exhibited superior sunlight photocatalytic activity for organic dyes degradation. N/La codoped ZnO–C and N/La codoped ZnO–O samples displayed remarkable photodegradation activities within 92–97% for CR, MG and MB in 60 min. N/La codoped ZnO–C showed a perfect photostability and reusability for four cycles. N and La enhance the charge carriers’ separation and the visible light absorption in ZnO which increase the photocatalytic activity.