Investigating the Impact of tin substitution on the Structural, Bioactive, and photocatalytic properties of titanite (CaTiSiO5) for water treatment purification

Abstract

This research addresses SDG 6, emphasizing clean water and sanitation through the development of materials that can photodegrade pollutants. Five Sn-substituted Titanite samples, Ca(Ti_1−xSn_x)SiO₅ (0.2 ≤ x ≤ 1), were synthesized via the solid-state method at 1100 °C. XRD and FTIR analyses confirmed a phase transition from Titanite (CaTiSiO₅) to Malayaite (CaSnSiO₅), with the Malayaite phase identified by a characteristic spectral band at 902 cm⁻¹. Bioactivity tests showed the formation of an apatite layer, with the highest degradation rate of 0.682 mm/year recorded for TS5 (x = 1-CaSnSiO₅) as verified by SEM. The band gap energy decreased from 4.66 to 4.35 eV with increasing Sn content. Photocatalytic tests revealed that higher Sn concentrations enhanced Methylene Blue (MB) degradation, with TS5(x = 1-CaSnSiO₅) achieving 88 % dye efficiency and a degradation rate constant of 4.47 × 10⁻³ min⁻¹, making it suitable for water purification applications.