Biofabrication of a bismuth vanadate/bacterial nanocellulose adsorbent: a photocatalytic mesoporous composite for efficient removal of a fluorochrome pollutant

The current work concentrated on a novel biofabrication method that employs bismuth vanadate (BiVO₄) nanoparticles and bacterial nanocellulose (BNC) to develop a bionanocomposite. The developed bionanocomposite was evaluated for its prowess in adsorption and degradation using the acridine orange (AO) dye. Comprehensive textural analyses were performed using FTIR, XRD, XPS, BET, FESEM, EDX, TEM, and TGA. Results revealed a dense nanofibrous network with enhanced thermal stability up to 600 °C. The N₂ adsorption–desorption isotherm showed its mesoporous nature, exhibiting a type IV structure. Adsorption data for AO adhered well to the Langmuir adsorption isotherm and 2nd pseudo-order kinetics, while thermodynamic analysis revealed a spontaneous, endothermic adsorption process. Remarkably, the bionanocomposite demonstrated regeneration capacity for up to five cycles. The photocatalytic prowess of the bionanocomposite was evaluated for AO degradation under visible light. Results illustrated BNC's role as a support, establishing an interface with BiVO₄ to reduce electron–hole recombination and heighten catalyst photodegradation efficiency. Photoluminescence analysis further validated this interaction by confirming suppressed electron–hole recombination in the composite. Findings highlight the bionanocomposite's efficacy in both adsorption and photocatalysis. Furthermore, the cytotoxicity assessment of the bionanocomposite on hepatocyte cells verified its non-toxic nature. This study illuminates the potential of a designed bionanocomposite model, offering a cost-effective, operationally simple, highly efficient, and environmentally benign solution to address dye pollution challenges.