One-Step Combustion Synthesis of Carbon-Doped BiVO4 Yellow Pigments with Enhanced Visible-Light Photocatalytic Antibacterial Performance

To integrate high chromaticity with visible-light-driven antibacterial functionality in yellow inorganic pigments, carbon-doped BiVO4 (C-BiVO4) pigments were synthesized via a one-step self-propagating combustion synthesis (SCS) using citric acid as a fuel and carbon source. The effects of citric acid dosage on phase composition, morphology, chromatic performance, and antibacterial activity were systematically investigated. The results indicate that carbon doping induces lattice expansion and oxygen vacancy formation, modulates the electronic band structure, and significantly suppresses photogenerated electron-hole recombination. At an optimal citric acid to BiVO4 molar ratio of 1.2, the pigment exhibits excellent yellow chromaticity (b* = 79.71). Under visible-light irradiation, C-BiVO4 achieves a methylene blue photodegradation rate of 96.63% and an E. coli inactivation efficiency of 99.99%, substantially outperforming undoped BiVO4. Moreover, the C-BiVO4 yellow pigment shows good dispersibility and thermal stability in PMMA and glass matrices and passes acute skin irritation and dermal toxicity tests, confirming its low toxicity and non-irritating nature. This work provides a new strategy for developing environmentally friendly inorganic pigments that combine high chromaticity with photocatalytic antibacterial functionality.