Investigation on Nanoarchitectonics of PJBAC/TiO₂ for Photocatalytic and Antimicrobial Performance

The present work focuses on the synthesis of Prosopis juliflora bark activated carbon supported on TiO₂ (PJBAC/TiO₂) composite through the sol-gel method for the decolourization of Direct Brown 2 (DB2). The prepared composite was characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. The surface area and pore diameter were explored by the Brunauer−Emmett−Teller method (N₂ adsorption/desorption). Furthermore, high-performance liquid chromatography (HPLC) and total organic carbon (TOC) analysis of the treated solution revealed a complete degradation of the dye molecule. The degradation efficiency of the prepared composite was analysed via batch equilibration studies. Maximum removal of DB2 (98%) was achieved at an initial concentration of 100 mg/L, contact time of 210 min, composite dose of 100 mg, and at pH 3. The well-known Freundlich and Langmuir isotherm equations were applied for the evaluation of equilibrium adsorption data. Lagergren and Ho−McKay kinetic models were employed to determine the adsorption rate constant. Additionally, the antimicrobial activity of PJBAC/TiO₂ was tested against Staphylococcus aureus, Escherichia coli, and Candida species. These results indicate that doping of TiO₂ on PJBAC inhibits the recombination of electron−hole pairs to improve photocatalytic performance in the visible region.