Unravelling the Potential of Biochar Derived Activated Carbon Functionalized TiO2 for Photocatalytic Degradation of Congo Red via RSM Optimization

Abstract

The increased dissolution of dyes into water bodies poses major environmental and health problems, highlighting the need for comprehensive dye pollution remediation. Photocatalysis is an intriguing solution to minimize the environmental harm triggered by these pollutants. Hence, this study establishes the green synthesis of TiO2, employing waste Artocarpus heterophyllus doped activated carbon (AC) derived from Juliflora wood. The morphological and elemental study revealed dispersion of TiO2 nanoparticles across AC (FE-SEM and EDX), while the ability of TiO2/AC (1:1) to operate in visible light was investigated using UV–vis, which revealed a band-gap of 2.10 eV. Several other characterization techniques such as FT-IR, BET, and TGA were used to investigate the physicochemical features of TiO2/AC (1:1). The photocatalytic activity was determined by their capacity for degrading Congo-red (CR) dye, with TiO2/AC (1:1) having the highest photocatalytic activity, with a degradation efficiency of 78.96%. To improve efficiency, experimental parameters (pH, photocatalyst loading, initial CR concentration, and reaction duration) were investigated using central composite design (CCD-RSM). A p-value of 0.0012 and an F-value of 17.44 proved that the model is statistically significant for CR degradation. Following 75 mins of visible light irradiation, 95.9% of the 20-ppm dye solution was degraded and revealed high recyclability and reusability over five consecutive cycles. Scavenging tests were also conducted to further understand the mechanism and reactive oxygen species (ROS) involved.