Enhanced solar-assisted degradation of Sunset Yellow dye using plant-mediated Ag-TiO2/Na-BNT nanocomposite: Synthesis, characterization, and performance optimization

Abstract

The research develops an innovative wastewater treatment method through silver-titania nanocomposite synthesis using sodium-functionalized bentonite (Ag-TiO₂/Na-BNT). The nanocomposite functions to achieve more effective solar-powered removal of Sunset Yellow dye which appears as a common industrial discharge contaminant. The Ag-TiO₂/Na-BNT nanocomposite was synthesized by hydrothermal methods followed by assessment using conventional analysis methods together with X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV–Vis spectroscopy, scanning electron microscopy-energy dispersive X-ray (SEM/EDX) and Fourier Transform Infra-red (FTIR) spectroscopy. These analyses showed Ag/TiO2 nanoparticles were adequately bonded to Na-BNT at uniform distribution thereby guaranteeing effective photocatalytic performance. The degradation capabilities of solar light-assisted nanocomposites were evaluated through Sunset Yellow dye as the target substance in tests. The research findings showed Ag-TiO₂/Na-BNT achieved enhanced degradation efficiency when exposed to solar light. Researchers investigated solar degradation conditions through experimental tests which evaluated various parameter settings including the pH of solutions and dye starting levels and TiO₂ amounts and H₂O₂ addition amounts. The combination of radical initiators increased the photodegradation efficiency of Ag-TiO₂/Na-BNT. Multiple performance-enhancing characteristics including greater degradation performance and improved solar utilization as well as optimized charge carrier separation enabled high performance. The removal of Sunset Yellow reached its peak at 98 % with nanocomposite usage only but surged to 99.9 % with the addition of hydrogen peroxide under conditions using 0.1 g catalyst loading at pH 3.0 and initial concentration of 10 mg/L while employing 0.1 M of 30 % H₂O₂. Researchers studied the multiple aspects of degradation time throughout their study. The Langmuir-Hinshelwood isotherm successfully defined the equilibrium values with R₂ = 0.9851 and the pseudo-first-order kinetic model best delineated the degradation reaction through R₂ = 0.9596. The discovered information reveals crucial information about how reactions proceed along with what factors influence degradation rates.