Fabrication, characterization, metal ions sensor and photocatalytic activity of visible light harvesting lead free perovskite oxide

The urbanization and industrialization maximizing worries of society by releasing highly toxic and complexed aromatic organic dyes as well as non-biodegradable, carcinogenic heavy metals, lethal to living bodies. The focus of the manuscript is fabrication of visible light harvesting photo catalyst for the degradation of organic dyes by advance oxidation process and sensing of heavy metal ions. In current study KSnFeMnO₆ (perovskite) (KSFMO) were produced and characterized by different techniques. The Fourier transform infrared (FTIR) and energy dispersive X-ray (EDX) results confirmed the synthesis of perovskite having all the characteristics peaks of the substituent elements. The band gap of the synthesized KSFMO was found to be 2.1 eV. The Scherrer equation revealed 10.67 nm average crystallite size of the perovskite. The point of zero charge (PZC) of the materials lies at 7.18 pH. The Eosin Blue (EB) degradation efficiency of perovskites KSFMO was 98.37 % at optimum conditions (time: 25 min, catalyst dose: 0.03g, EB concentration: 60 mg/L, pH of solution: 3). Eq. 10 obtained from response surface methodology (RSM) shows that catalyst dose has more significant effect on the removal of EB. The EB degradation followed first order kinetic with R² and rate constant values of 0.976 and 0.144 s⁻¹ respectively. To validate and optimize experimental variables RSM method was employed. The analysis of variance (ANOVA) results showed the significance of the fitted model. The statistical investigations were in good agreement between the proposed model and experimental data. The adequate precision (AP) value was found to be 69.4363, and the low coefficient of variance (CV) value of (2.41 %) confirmed the validity and reliability of the proposed model and obtained data for photo degradation. The optical sensitivity of KSFMO was investigated towards different metal ions. The maximum quenching of the fluorescent spectra was observed for Pb²⁺ having 1.30 × 10⁷ K_sv value. These findings suggest that KSFMO has promising potential as an effective photo catalyst and lead sensor, therefore it could be useful as a Pb²⁺ probe in industrial effluents.