Insights into the Distinguishable Photophysical Properties, Photocatalytic Efficiency, Breakdown Financial Cost and Recycling Process of Pure and Doped SnO2 Quantum Dots Via Actual Natural Wastewater Treatment

Abstract

This study details the distinguishable sonochemical synthesis of titanium-doped and pure tin dioxide quantum dots (SnO₂Qs) and a comprehensive examination of their structures. XRD analyses affirmed the crystallinity and phase purity of the tetragonal SnO₂Qs, revealing crystallite sizes with average of 4.20 and 6.50 nm for SnO₂Q1 and SnO₂Q2, calcined at 290 and 490 °C, respectively. HRTEM imaging delineated spherical particles with 4.75 nm for SnO₂Q1 and 8.30 nm for SnO₂Q2. The energy band gap was determined as 3.31 eV for SnO₂Q1 and 3.37 eV for SnO₂Q2. Photocatalytic efficiency was estimated by photodegradation of Brilliant blue R dye under Xenon lamp light, where the rate constant for SnO₂Q1 was 11% higher than SnO₂Q2 owing to its smaller size by 35% and larger BET surface area by 21%. Also, solar irradiation, with SnO₂Q1 sustaining its photocatalytic activity across seven reuse cycles. An economic analysis, for the Brilliant blue R dye, the cost efficiency of photodegradation process in presence of SnO₂Q1 costly less than SnO₂Q2 cost from 25.07 to 26.24 $ while 2% Ti-doped Sn_0.098Ti_0.02O₂ (SnT1) was cheaper than 8% Ti-doped Sn_0.092Ti_0.09O₈ (SnT2). These findings underscore the exceptional photocatalytic efficiency and cost-effectiveness of SnO₂Qs samples as sustainable options for actual natural wastewater treatment.