Differences effect of dominant charge dynamics between fullerene and non-fullerene photocatalysts on the degradation for neonicotinoid insecticides

Neonicotinoid insecticides used for agricultural pest control pose severe threats to non-target organisms and ecosystems due to their high water solubility, environmental persistence, and bioaccumulation. To address the water pollution caused by such insecticides, this work effectively removed neonicotinoid insecticides by loading the PTQ10:Y6 and PTQ10:PC71BM onto coconut shell charcoal and investigated the dominant charge dynamics differences between the non-fullerene Y6 and the fullerene derivative PC71BM system photocatalysts. Compared with the fullerene derivative PC71BM, the non-fullerene Y6 system photocatalyst exhibited lower charge recombination, higher carrier mobility, and stronger transient photocurrent response. As a result, when 100 mg of PTQ10:Y6 photocatalyst is used to treat 50 ml imidacloprid (10 mg l−1), the PTQ10:Y6 catalyst achieved a degradation efficiency of over 96% within 30 min and maintained an efficiency of 92% after 15 consecutive cycles. Moreover, two possible degradation pathways and products are inferred through the Fukui function and liquid chromatography–mass spectrometry. Toxicological analysis indicated that the toxicity of almost all the intermediate products is very low. More importantly, the Y6 photocatalyst can also widely degrade solutions such as thiacloprid and thiamethoxam with a concentration of 10 mg l−1 within 30 min. This work reveals that due to the superior charge dynamics characteristics, the Y6 heterojunction photocatalyst system is expected to be applied in the remediation of pesticide pollution.