Eco-Friendly Synthesis and Structural Stabilization of Sb-Doped SnO₂ Nanocatalysts Prepared via Pechini Route for Sustainable Chemical Applications

This research presents the eco-friendly synthesis and detailed structural characterisation of antimony-doped tin oxide (SnO₂:Sb) nanocatalysts developed for sustainable chemical transformation applications. Samples containing 0–18 mol% Sb were synthesised using the polymeric precursor (Pechini) method and subjected to calcination between 800 °C and 1200 °C for four hours. The microstructural evolution, crystallite size, lattice parameters, and strain behaviour were examined using X-ray diffraction coupled with Rietveld refinement. Complementary high-resolution transmission electron microscopy supported particle morphology interpretation. Results demonstrate that Sb incorporation effectively stabilises SnO₂ nanoparticles, suppresses abnormal grain growth, and promotes controlled crystallite development. The doping concentration and temperature significantly influenced oxidation states of antimony (Sb³⁺/Sb⁵⁺), which in turn affected lattice expansion, oxygen vacancy formation, strain relaxation, and crystallinity. Overall findings confirm that Sb-doped SnO₂ prepared via an environmentally benign approach is structurally robust, thermally stable and suitable for high-performance catalytic systems aligned with green chemistry objectives.