| The chemical pesticide has made availability contributions for provisionment of mankind and prevention and cure of deleterious biology since they came out the 1930s of the last century. At the same time they also led to some negative effects. With the development of science and technology, more and more measures can be adopted to control pests, while more and more severe negative effects were brought out. Thereby, now scientists focus on the investigation of the green pesticides and furmulation which mostly deals with study of super highly-active,lowly poisonous, lowly residual and noncontaminated chemical pesticide.Thereinto studies on green nano-pesticides with photocatalytic degradation activity attract increasingly attentions. In this article, the carriers of photodegradation sources have been prepared, and were modified to enhance photocatalytic activity, their surfaces were changed by organic compound for highly absorption capability to pesticides. The research also involved on furmulation of nano-pesticide, its activity of biology and the residual toxicity of nano-pesticide, and so on. The pertinent investigative works have been carried out as follows:Nanosized TiO2 particles were prepared by direct hydrolysis of Ti(SO4)2 at a certain temperature, colloidal sol, addition of crystal seeds and ageing. The particles were of good single dispersedness and thermal stability with about 22 nm diameter and above 80 m2·g-1 ratio surface. The concentration of Ti(SO4)2, hydrolysis time, addition of crystal seeds, calcination temperature and time had a large influence on particle diameter and reunite. The nanometer TiO2 were modified by alkaline-earth metal oxides, and the optimal mole percentages of Mg, Ca, Sr and Ba were 0.5%, 1.0%, 1.5% and 1.5%, respectively which gave highly photocatalytic activity. The photocatalystic activity was considerably dependent on pH and the concentration of the oxides. The parameter of TiO2 crystal lattices decreased with addition of alkaline-earth metal oxides under optimal mole percentages, whichaggreed with the photocatalytic activity of composite catalysts in sunlight. The results of UV-light and sunlight degradation experiments showed that the efficiency of composite catalysts were increased about 10% than that of pure TiO2 for methyl orange degradation.Nanometer TiO2 depositeded with Ag was prepared through H2 reduction . Results showed that Ag was distributed uniformly on TiO2 surface and the Einstein shift was observed clearly on the UV-vis absorption spectrum. The optimized depositing amount of Ag was 0.25% (molar ratio of Ag to TiO2) which was far less than other methods. The optimum concentration of photocatalyst was 1.25g-L'in the UV light degradation reaction. Compared with pure TiO2, photocatalytic activity Ag/TiO2 was increased doublely under methyl orange degradation in sunlight. The methyl orange degradation reaction coincided well with the dynamics principle of the apparent first-order reaction for the different catalyst. TiO2's external property and electro-property were affected by deposited Ag, also its photocatalytic activity was improved.Photocatalysts of TiO2/B2O3 was prepared via sol-gel method, and its photocatalytic activity was evaluated by degradation of xylenol orange solution. The photocatalyst showed the highest photocatalytic activity when B2O3:TiO2was 2.5% and roasted at 700°C for lh, the activity was higher 12% than that of pure TiO2. There was higher changed temperature of crystal and lower reunited degree for TiO2/B2C>3 than that of TiO2. The increasement of photocatalytic activity was probably ascribed to the scanty electron property of boron through analyzing seized manner of produced electron-hole by light and adsorption action of organic compound on photodegradation source.The photocatalytic degradation of dimethomorph and chlorfenapyr in a suspension with Ag/TiO2 as catalyst was carried out by radiation of UV-light and sunlight. A pseudo-first-order kinetic model was used to describe the results. The results showed that the decomposed ratio of DMM was 94%, when the usage of catalyst was 1.25g-L"', the concentration of DMM was lOOmg-L"1, pH of solution was 7, thequantity through air was 1.5 L-min"1, and it was irradated 5h by UV-light. When it was irradiated by sun-light under the same condition, the decomposed ratio of DMM was 48%. The photocatalytic degradation was processed for Chlorfenapyr, and the decomposed ratio of chlorfenapyr was 85% by UV-light and 42% by sun-light, when the dosage of catalyst was 1.00 g-L"1, and the other conditions were similar. The simulant nano-pesticide furmulation of dimethomorph and chlorfenapyr were prepared by modified photocatalytic degradation, and irradiated experiments were progressed. The results showed that the photocatalytical adsorption for pesticide and photodegradation activity had markedly effect. According the quantum chemistry account, the most atoms were of negative charge in the molecules of dimethomorph and chlorfenapyr and projecting in space. This helps to absorb catalysts and form hydrogen bonds under the acid condition. Hence, the degradative activity was improved. The mechanism of dimethomorph's decomposition was discussed based on the data by analysis of LC-MS.The absorption behaviors of the polar and non-polar organic compound on the surface of the nano-TiO2 and the modified nano-TiO2 were investigated by technology of Quartz Crystal Microbalance. The results showed that the adsorption ability of TiO2 particles were advanced to modified with Ag+, silicon oil, stearic acid and sodium dodecyl sulfonic. The most adsorptive quantity was increased one time in comparing with the original TiC>2. When nano-TiO2 particles was modified with stearic acid and silicon oil. The adsorption of methyl parathion on the surface of nano-TiO2 modified with stearic acid was also studied. The result showed that the amount of the adsorption of methyl parathion on the surface of nano-TiO2 was advanced 3 times. The work has not been reported in any other literatures.Several projects have been adopted to produce the furmulation of nano- pesticide which is practically friendly to the environment. Comparing to the different furmulations, there were higher photodegradation activity for the furmulations of nano-pesticide byUV-light and sunlight. The results of experiments both indoors and outdoors showed that the addition of the photodegradation source in pesticides can not decrease the toxicity of pesticide. On the contrary it even can increase the pesticide's biology toxicity (above 1.5 times). Their ti/2 for chlorfenapyr nano- formulation and chlorfenapyr suspension concentrate were 3.91 day and 8.64 day respectively in the soil. Their t1/2 for chlorfenapyr nano-formulation and chlorfenapyr SC were 1.27 day and 3.27 day respectively in the cabbages in clear up dynamic test. In conclusion, photodegradation source can preferably decrease the residual of pesticide both in the body of plant and in the soil. The very high estimate and attention were obtained by craft brother experts and interrelated branches.
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