Investigating the structural and photocatalytic characteristics of SrO-SnO₂ nanocomposites

Structural and photocatalytic properties of strontium oxide nanoparticles (SrO NPs), tin oxide nanoparticles (SnO₂ NPs) , and SrO-SnO₂ nanocomposites (SS NCs) synthesized by coprecipitation-sintering method were evaluated. The SS NCs were synthesized by varying the concentration of SnO₂ precursor from 0.2 to 1.0 mol (SS-0.2, SS-0.4, SS-0.6, SS-0.8, and SS-1.0). The coprecipitated SrO-SnO₂ mixture was subjected to sintering at 800 °C for 2 h. The infrared spectra and XRD patterns confirmed the formation of SS NCs. The grain size of SS NCs was decreased in response to an increase in the proportion of SnO₂. Where the band gap was increased. The gain size (nm)/band gap (eV) of SrO, SnO₂, SS-0.2, and SS-1.0 were 50.3/2.09, 36.45/3.69, 66.22/3.24, and 37.34/3.66, respectively. SrO NPs with special, rod, cubic, and random morphology were obtained. SnO₂ NPs was largely random aggregates. The morphology of SS NCs had a diverse morphology, reflecting the morphology of their corresponding constituents. The BET analysis demonstrated the intermittent surface area compared with their bare constituents and mesoporous morphology. Photocatalytic efficiency was studied using malachite green (MG) dye and benzene. The MG was used as the primary target, where SS-0.4 exhibited the highest efficiency under natural sunlight. Cross-verification experiments performed using the NCs synthesized by varying the SrO proportion also confirmed the same. Reactive oxygen species analysis were performed using scavenger molecules, revealing the domination of superoxide (O₂•), and hole (h+) mediated photooxidation. The maximum degradation efficiency noticed for MG and benzene was 95% and 99%, respectively. Optical and photocatalytic studies indicated the functioning of SS NCs as heterojunction photocatalysts.