Insight into the adsorption, photocatalytic and magnetic properties of bandgap tailored hydrothermally grown SnO2:Ni/Cu nanostructures

Application of pristine and (2.5–5) wt% Ni, Cu doped SnO2 as adsorbent for the removal of Malachite green (MG) dye under natural solar light has been investigated in the present study. Synthesized nanostructures are characterised by XRD, XPS, BET, FESEM and UV–Visible spectroscopy. Sorption data were examined using Lagergren's pseudo first order, second order and intra particle diffusion kinetic models. Pseudo second order kinetic model was found suitable for describing the adsorption mechanism in this study. The calculated thermodynamic parameters revealed the endothermic, spontaneous and thermodynamically feasible nature of sorption mechanism of MG dye onto pristine and doped SnO2 nanostructures. Compared with other samples, 5% Cu doped SnO2 showed better photocatalytic degradation efficiency by removing 81.42% percentage of initial dye concentration within 240 min of contact time. SQUID measurement gave an account on the existence of ferromagnetic behaviour for Ni and Cu doped SnO2 nanostructures.