Highly efficient g-C3N5/Bi2MoO6 heterojunction for aflatoxin B1 photocatalytic degradation

Aflatoxin B1 (AFB1) poses a significant threat due to its highly toxic, carcinogenic, and teratogenic characteristics, thus seeking efficient photocatalysts for AFB1 degradation is extremely urgent. Among the promising photocatalysts, bismuth molybdate (Bi2MoO6) has garnered attention for its application in photodegradation of organic pollutants. However, its inefficiency in responding to visible light, inclination to aggregate, and low effectiveness in separating photogenerated carriers have hindered its widespread utilization. In order to enhance the separation and migration efficiency of photogenerated carriers in Bi2MoO6, the g-C3N5/Bi2MoO6 (CN/BMO) heterojunction was engineered by combining Bi2MoO6 with g-C3N5. This integration also improved the visible light response of CN/BMO composite due to the narrow band gap of g-C3N5. Under visible light irradiation, the degradation rate of AFB1 (1 mu g/mL) by CN/BMO-2 composite can reach 92 % within 75 min. After 4 cycles, the CN/BMO-2 composite still exhibited a good photocatalytic stability. Additionally, center dot O-2(-) was identified as the main active species in the photocatalytic process. The deactivation mechanism of AFB1 during photodegradation was also investigated through high-resolution mass spectrometry (HRMS). The active species has been confirmed to firstly attack the cyclopentanone at the end of the furan ring of AFB1 to achieve detoxification. This research offers a theoretical framework to enhance comprehension of the deactivation process of AFB1.