Efficient Photocatalytic Rhodamine B Dye Degradation Using Activated Carbon-Based TiO 2 Photocatalyst
Year: 2026
Type: article
Abstract: Environmental contamination caused by synthetic dye effluents from the textile, paper, and printing industries poses severe ecological threats. In this work, a highly efficient activated carbon-based titanium dioxide (AC-TiO 2 ) composite photocatalyst was successfully synthesized via a modified sol-gel route for the targeted degradation of Rhodamine B (RhB) dye under simulated solar irradiation. The synthesized materials were comprehensively characterized using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), X-ray Photoelectron Spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) surface area analysis. XRD confirmed the formation of highly crystalline anatase-phase TiO 2 , while BET analysis revealed that the integration of activated carbon drastically enhanced the specific surface area from 52.4 m 2 /g (pure TiO 2 ) to 284.7 m 2 /g (AC-TiO 2 ). UV-Vis DRS displayed a prominent red shift in the absorption edge of the composite, effectively narrowing the band gap energy from 3.20 eV to 2.85 eV, enhancing light absorption in the visible range. Photocatalytic performance evaluation showed that the AC-TiO 2 composite achieved a superior RhB degradation efficiency of 98.5% within 60 minutes of irradiation, significantly outperforming benchmark Aeroxide P25 (71.2%) and pure TiO 2 (63.4%). Kinetic analysis revealed that the degradation followed a pseudo-first-order mechanism, with a rate constant (k = 0.0681 min⁻ 1 ) that is ~ 4.3 times higher than pristine TiO 2 . The synergistic mechanism is attributed to the dual role of activated carbon as an exceptional adsorptive sink and an electron trapping mediator that effectively retards the recombination of photogenerated electron-hole (e⁻/h⁺) pairs. Furthermore, scavenger experiments confirmed that hydroxyl radicals ( • OH) and superoxide radical anions ( • O 2 ⁻) acted as the dominant reactive oxygen species driving the mineralisation process. The composite displayed excellent reusability, maintaining a 92.1% degradation efficiency after five consecutive cycles, demonstrating high stability. This study highlights the potential of AC-TiO 2 composites as an eco-friendly, cost-effective, and highly viable candidate for high-throughput industrial wastewater remediation.
Author: Sagar Kande
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7204597979