Photocatalytic degradation of aflatoxin B₁ by porous carbon nitrides under visible light

Porous graphitic carbon nitride (g-C₃N₄), which exhibits a sensitive response to visible light, was prepared through a simple thermal condensation process. It was then used to investigated its efficiency in degrading aflatoxin B₁ (AFB₁). The factors affecting the degradation efficiency of AFB₁, including precursors of g-C₃N₄, visible light sources, pH value, and irradiation time were investigated. The porous g-C₃N₄ prepared using melamine as the precursor, exhibits improved crystallization performance and higher photocatalytic activity. The degradation rate of AFB₁ reached 98% under the visible light of a metal halide lamp for 90 min, and the degradation process was fitted with the pseudo-first-order kinetic model. In addition, superoxide radicals (^·O₂⁻) and holes (h⁺) play important roles in reducing AFB₁. The five degradation products primarily result from damage to the lactone and furan ring structure, which initially demonstrate a decrease in AFB₁ toxicity. This study provides an effective, environmentally-friendly, and practical approach for reducing AFB₁.