Strategies for enhancing hole utilization on organic-POM hybrid materials and photocatalytic degradation of neonicotinoid insecticides

Ammonium phosphotungstate/pyromrllitic diimide (NH4PW/PMDI) composite photocatalysts were prepared using organic amines and ammonium respectively. The characterization results showed that although the chemical structure and chemical environment of each element were the same, the NH4PW/PMDI composite photocatalysts showed differences in photoelectric properties, which was caused by their different morphologies. The source of organic amines and ammonium may influence the distribution of NH4PW in the NH4PW/PMDI. The NH4PW on the surface can improve the light absorption ability, while the NH4PW on the inside can inhibit the recombination of electron and hole. And imidacloprid can be adsorbed at the surface of NH4PW through hydrogen bonding between nitrogen atoms and ammonium, which increases the electron density of nitrogen atoms that is conducive to the attack of photogenerated holes. The degradation rate constants of 15UNPWPI-325 for imidacloprid, thiamethoxam and acetamiprid were 2.8488, 1.4784, and 0.9372 h-1, respectively.