مائده حسين زاده

Persistent organic pollutants pose a serious challenge to water resources due to their toxicity an‎d long-term environmental impacts. In this study, a BiVO₄/TiO₂ composite photocatalyst was synthesized via the solution combustion method using urea as fuel, aiming to develop an efficient visible-light-driven photocatalyst. Initially, TiO₂ was synthesized using different fuels (urea, glycine, an‎d citric acid) an‎d comparatively eva‎luated; the urea-derived TiO₂ exhibited superior photocatalytic performance along with more favorable optical an‎d structural properties an‎d was therefore selec‎ted as the composite support. Subsequently, BiVO₄/TiO₂ composites with various BiVO₄ weight ratios (10–50 wt%) were prepared. XRD an‎d FESEM analyses confirmed the successful formation of the dual-phase structure an‎d a stable heterojunction between TiO₂ an‎d BiVO₄. UV–Vis DRS an‎d PL results revealed that the incorporation of BiVO₄ extended light absorption into the visible region an‎d reduced the ban‎dgap energy to approximately 2/4 eV This ban‎dgap narrowing was intentionally achieved to enhance visible-light utilization, promote effective charge carrier generation, an‎d improve photocatalytic activity. Photocatalytic experiments under visible-light irradiation demonstrated that the 30 wt% BiVO₄/TiO₂ composite exhibited the highest performance, achieving approximately 95% degradation of methylene blue under alkaline conditions an‎d about 70% under acidic conditions, which is attributed to efficient charge separation an‎d interfacial charge transfer. The antibacterial properties were eva‎luated using the viable cell counting method against both Gram-positive an‎d Gram-negative bacteria. The results indicated that urea-derived TiO₂ an‎d the 30 wt% BiVO₄/TiO₂ composite showed the highest antibacterial activity, achieving approximately 99/99% bacterial growth inhibition at a concentration of 5000 ppm. This activity is attributed to the generation of reactive oxygen species an‎d subsequent disruption of bacterial cell walls. Overall, solution combustion synthesis using urea is demonstrated to be a rapid, cost-effective, an‎d efficient approach for producing BiVO₄/TiO₂ composites with high photocatalytic an‎d antibacterial performance for pollutant remediation.

سنتز احتراقي , تيتانيم دي اكسيد , بيسموت وانادات , كامپوزيت , فتوكاتاليست

Combustion synthesis, Titanium dioxide, Bismuth vanadate, Composite, Photocatalyst

Maedeh Hosseinzadeh

Dr. Seyyed Morteza Masoudpanah Dr. Amirmahmoud Bakhshayesh