Interface-Engineered Palmyra Palm-Derived Activated Carbon/BiVO₄ Nanohybrids for Enhanced Degradation of Carcinogenic Dye under Dark and Light Conditions

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发表日期：

2026年6月10日

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K. Sumi,
R. C. Aashika,
K. S. Supraja,
M. Arivanandhan

摘要

Tailoring the bandgap in heterogeneous photocatalysts presents a powerful approach to boost redox reaction efficiency by facilitating better charge separation and mobility. In the present study, activated carbon (AC)-modified bismuth vanadate (BiVO₄) nanocomposites (ABV) were synthesized via a hydrothermal technique. These composites were studied for their ability to degrade Rhodamine B (RhB) dye in water, both in the absence of light (dark conditions) and under visible light illumination. Comprehensive characterizations of the ABV materials were conducted using X-Ray Diffraction (XRD), UV-visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Brunauer-Emmett-Teller (BET) surface area analysis, and Photoluminescence (PL) spectroscopy. The results demonstrated that AC significantly enhanced the adsorption capacity in the dark, while BiVO₄ exhibited strong photocatalytic activity under visible light. The synergistic coupling between AC and BiVO₄ narrows the bandgap, thereby enhancing visible-light absorption, and effectively suppresses electron-hole recombination due to interfacial charge transfer and defect-state formation, thereby improving photocatalytic efficiency. The optimized ABV-6 composite achieved an impressive RhB degradation efficiency of 93.3% in 60 min in the dark, and nearly complete removal of 99.6% in just 35 min under visible-light exposure. Under visible light illumination, the observed degradation rate constant was 0.1648 min^-1, corresponding to a half-life of approximately 4.2 min. In the dark, the rate constant was 0.0465 min^-1, with a half-life of 14.9 min, emphasizing the role of light in accelerating photocatalytic activity. The exceptional stability and reusability of the ABV-6 nanocomposites highlight their potential as sustainable photocatalysts for wastewater treatment applications.