High antibacterial and photocatalytic activity of solution combustion synthesized Ni0.5Zn0.5Fe2O4 nanoparticles: Effect of fuel to oxidizer ratio and complex fuels

Abstract High antibacterial and photocatalytic Ni0.5Zn0.5Fe2O4 nanoparticles were synthesized via solution combustion synthesis method using complex fuels i.e. glycine & urea. Employing a mixed-fuel system for synthesis of nanopowders improved the photodegradation of methylene blue as dye molecule to 85% along with 100% growth inhibition against bacteria (E. coli and S. aureus). The minimum inhibitory concentration of particles was 0.25 mg/mL and 0.125 mg/mL against the gram-negative and gram-positive bacterium, respectively. The effect of fuel type (glycine & urea), fuel to oxidizer ratio (φ = 0.8, 1, and 1.4), and complex fuels (mixing urea and glycine with different molar proportions) on the synthesis process as well as the physicochemical properties of the as-synthesized nanopowders were investigated. XRD, FTIR, EDS, and elemental mapping results implied that the formation of single-phase product relied on the φ value. Well-crystalline single-phase Ni0.5Zn0.5Fe2O4 particles with an estimated crystallite size of 8.9-22.4 nm, were synthesized at φ=0.8 and 1.4. Combusted particles using urea at φ = 1.4 displayed saturation magnetization of 67 emus/g (without further sintering process), the specific surface area of 150 m2/g, and particle size around 30 nm.