Facile synthesis of SnO2/NiO nano-composites: Structural, magnetic and catalytic properties

Environmental pollution, one of the major challenges being faced by life forms on our planet, can be controlled to some extent by degrading organic pollutants using heterostructured nanoparticles. This paper reports the fabrication of SnO2/NiO nano-composites by a simple, environmentally benign and cost effective two - step process via precipitation using tannic acid, a green reagent. Thermal analysis shows the optimum annealing temperature as 500 degrees C.Fcc structured NiO and tetragonal SnO2 in the nanocomposite is confirmed from XRD analysis. The interplanar spacing of 0.33 nm in SnO2 for (111) and 0.20 nm in NiO for (200) planes observed in the HRTEM images confirms the composite formation. The synthesized composites characterized using UV-Vis spectra give band gap energies of the samples. The elemental composition and oxidation states have been supported by EDX and XPS analyses. VSM study carried out at room temperature show enhanced ferromagnetic properties with increase in NiO content. The probe reactions degrading Methylene Blue and Eosin Yellow show the effective catalytic potential of the synthesized SnO2/NiO nano-composite. Efficient degradation of 98% and 97% could be achieved in 14 and 20 min, respectively, showing suitability as a promising candidate in waste water treatment.