Ni–ZnO nanocomposites assembled under various morphologies like columnar, nanochains, and granular structure for removal of pollutants

Abstract

A unique three dimensional (3D) porous Ni–ZnO heterojunction nanocomposites were synthesized by a simple sonochemical approach followed by annealing the zinc and nickel oxalate composite precursor formed at 400–600 °C. Simple calcination leads to generate novel 3D porous nanostructures such as columnar, nanochain, and granular structure with a high surface area. Also, the prepared morphological Ni–ZnO nanostructure provides an efficient photocatalytic improvement under visible light range. The columnar-like morphology Ni–ZnO photocatalyst degrades 100% of methylene blue (MB) in 270 min while the methyl orange (MO) in 360 min under visible light irradiation. Ni–ZnO nanocomposites calcined at 400 °C shows relatively high adsorption capacities for MB and MO due to good electrostatic interaction between Ni–ZnO and dyes. Whereas Ni–ZnO nanocomposites calcined at 500 °C and 600 °C have fewer adsorption capacities for MB and MO due to aggregation of particles.