Rapid one pot synthesis of Ag/ZnO nanoflowers for photocatalytic degradation of nitrobenzene

[Display omitted] •Well defined flower like Ag/ZnO heterogeneous nanostructures are synthesized.•A feasible growth mechanism for the formation of flower like structure is discussed.•Structural, morphological and optical properties are discussed.•Ag/ZnO nanostructures significantly enhanced the degradation of nitrobenzene.•The degradation products are analyzed and degradation mechanism proposed. We report a rapid one pot synthesis of flower like Ag/ZnO heterogeneous nanostructures. Ag/ZnO have been synthesized via surfactant-free microwave/ultrasound assisted aqueous solution method. The size of the flower petals ranges from 200 to 250 nm and a substantial amount of silver nanoparticles were deposited on the petals of the flowers. The method qualifies to be energy conserving and environment friendly. The influence of silver nanoparticles on the surface of ZnO flower has been emphasized by applying the as synthesized nanostructures in the degradation of a recalcitrant organic compound nitrobenzene under the illumination of visible light. The Ag/ZnO flowers synthesized by microwave irradiation and ultrasound exhibited 98% degradation efficiency within 100 and 120 minutes respectively that is 2.9 times more than pure ZnO that shows only 33.6% degradation by the end of 120 minutes. The degradation products were analysed by HPLC and FTIR spectroscopy and based on that an oxidative degradation mechanism was proposed.