Efficient and novel synthesis of Nb-doped SrTiO3 nanoparticles via microwave-assisted sol-gel auto-combustion

Abstract

This study employed microwave-assisted sol-gel auto-combustion to synthesize niobium-doped strontium titanate (SrTi1-xNbxO3, STNO) nanoparticles, targeting enhanced photocatalytic performance applications. The STNO with varying levels of Nb doping (x = 0 to 0.05), was successfully synthesized utilizing the rapid and novel microwave-assisted sol-gel auto-combustion technique. The synthesized nanoparticles consistently exhibited a pure cubic perovskite structure across all doping levels, as confirmed by Rietveld refinement, which also showed an increase in lattice parameters and unit cell volume with higher Nb content. Morphological analysis revealed uniformly cubic-shaped particles with sizes ranging from 60 to 180 nm. The bandgap energy (Eg) remained unaffected by the varying Nb doping levels. Regarding photocatalytic activity for the degradation of methylene blue (MB) dye and tetracycline (TC) antibiotic under UV-A LED irradiation, the photocatalytic performance of STNO was significantly enhanced with increasing Nb content. The optimal photocatalytic decolorization was achieved at x = 0.05, aligning well with findings derived from photoluminescence (PL), Eg, Nyquist plot analyses and band edge potentials. Therefore, microwave-assisted sol-gel auto combustion is one of the efficient and novel methods to synthesize metal oxide materials.