Preparation of mesoporous ammonium phosphotungstate/silica catalyst and study on the degradation performance of chlorothalonil

Abstract

Chlorothalonil is widely used to control fungal diseases and it is usually detected in the environment. The phototransformation is an important process to remove Chlorothalonil from the aquatic environment. The mesoporous ammonium phosphotungstate/silica catalyst (NH4PW/SiO2) was synthesized from cetyl trimethyl ammonium bromide (CTAB) and tetraethoxysilane (TEOS) as raw materials by adding insoluble ammonium phosphotungstate into the alkaline alcohol-water system by sol-gel method. The structure of NH4PW/SiO2 was characterized by X-Ray Diffractomer (XRD), Brunauer-Emmett-Teller (BET) and Fourier Transform infrared spectroscopy (FT-IR). The photocatalytic activity of NH4PW/SiO2 was evaluated by using the organic pesticide chlorothalonil as a model reactant. The result indicated that when the dosage of NH4PW/SiO2 is 0.02 g, the illumination is 180 min, the concentration of chlorothalonil is 5 mg/L, pH = 5, the degradation effect is better, and the degradation rate reaches 83.23%. The results contributed to understanding of chlorothalonil phototransformation and the potential of mesoporous SiO2 to effectively enhance the photocatalytic activity of NH4PW (64.16%) to reduce aquatic toxicity and pollution of chlorothalonil.

Preparation and Properties of Fomesafen@SiO2-Starch Microspheres for Herbicide-Controlled Release

“…The porosity of core–shell nanoparticles will affect the retention of drugs in the mesoporous channels of nanoparticles, which reduces the possibility of drug sudden release and can better sustain the effect on plants. Therefore, it is meaningful to use silica nanocarriers with high porosity and uniform size for drug delivery. − Plant mesophyll cells contain α-amylase, which can catalyze the starch in plant leaves to form hexose phosphate, which is the key substance of cell synthesis . Thus, using the property of continuous secretion of α-amylase by plants, the pesticide can be made to have an α-amylase responsive exterior coating of starch, which not only facilitates the release of the pesticide but also reduces the effects of UV radiation and decreases the potential for crop leaf scorch .…”