Preparation Of Several Novel Sonocatalysts And Sonocatalytic Degradation Of Common Drugs In Aqueous Solution

Now,drugs are still a nightmare that people cannot escape.Although governments have been working hard to prohibit drugs,the areas of poisonous source continue to emerge,and the prosecution of precursor chemicals has continued unabated.Synthetic drugs have emerged in an endless stream,and the drug consumption market continues to expand.At present,the drug problem in our country presents a situation of total encirclement and infiltration everywhere.Smuggling and consumption co-exist and manufacturing and trafficking are common.Especially in recent years,the criminal activities of illegally producing and trafficking in new types of drugs such as methamphetamine,2-?methylamino?-1-phenyl-1-propanone,and “Kai” have been increasing.There are hundreds of cases of illegal drug production detected each year.As many as tens of tons of refined pharmaceuticals controlled by various countries have been seized,while semi-finished products of drugs,narcotics solutions,effluent containing drugs,and bodies of water contaminated with drugs are counted in 10,000 tons.For drugs,traditional incineration and landfilling seriously pollute the atmosphere,water bodies and soil,causing great harm to the environment.And that is incompatible with environmental protection laws.The harmless treatment of drugs has become a world problem,gradually attracting the attention of governments and environmental protection agencies in various countries.In recent years,the field of semiconductor photocatalysis developing rapidly has attracted extensive attention.And a large number of semiconductor photocatalytic materials with excellent performance have been prepared and applied in the fields of environment and energy.In addition,as an advanced oxidation technology,ultrasonic waves,because of their superior penetrability,are particularly suitable for the treatment of dark and opaque drug-containing liquids.The perfect combination of photocatalysis and ultrasonic degradation technology is promising for the harmless treatment of drugs.In recent years,our group has been engaged in the preparation of semiconductor sonocatalysts and the research of ultrasonic catalytic degradation of common drugs.We have found that the semiconductor material with wide band gap mixed with the narrow bandgap one or the up-converting agent,the ultrasonic catalytic activity was significantly improved.Based on this,we designed and prepared several semiconductor sonocatalysts to degrade common drugs.The main results are concluded as follows:1.We synthesized Nb₂O₅ nanopowders by hydrothermal method and X-ray powder diffraction?XRD?,energy dispersive X-ray spectroscopy?EDX?,scanning electron microscopy?SEM?and UV-visible absorption spectroscopy?UV-vis?were used for characterization.The catalyst was used to ultrasonically degrade ketamine in aqueous solution.The effects of ultrasonic power,calcining temperature,ultrasonic temperature and recycle times on the degradation were investigated.We also analyzed the degradation products of ketamine by GC-MS.It was showed that Nb₂O₅ nanomaterial calcined at 500 °C for 1.0 h showed good catalytic degradation effect.Moreover,Nb₂O₅ materials are stable in nature,insoluble in water,and can be recycled many times.2.Due to the wide bandgap of Nb₂O₅,the shorter wavelength ultraviolet light in sonoluminescence can only be selectively used.We synthesized the up-conversion luminescence agent Er³⁺:YAlO₃ by sol-gel method,and synthesized composite sonocatalysts Er³⁺:YAlO₃/Nb₂O₅ via hydrothermal and ultrasonic dispersion method.The methamphetamine was used as target degradation material to study the degradation activity of Er³⁺:YAlO₃/Nb₂O₅ catalysts.The catalytic activity of the composite catalysts was also investigated.The results showed that the composite catalyst calcined at 500 °C for 1.0 h,could degrade methamphetamine of 10.0 mg/L about 82.17 % for 5.0 h,under the condition of ultrasonic power of 700 W,frequency of 45 k Hz,and system temperature of 30 °C.Through GC-MS analysis,we found that methamphetamine was quickly decomposed into harmless substances.3.We synthesized a series of composite catalysts Er³⁺:YAlO₃/Ta_xNb_yO₅?x+y=2?by hydrothermal and ultrasonic dispersion method,and characterized the catalysts.We used the catalysts to degrade aqueous caffeine solution of 10.0 mg/L and examined the catalytic activity of the composite catalysts.The results showed that when the mass ratio of Er³⁺:YAlO₃ to Ta_xNb_yO₅?x+y=2?is 0.15:1 and the ratio of Ta2O5 to Nb₂O₅ is 0.5:1.5,and the catalyst was calcined at 500 °C for 1.0 h,the degradation of caffeine could reach 82.62 % after irradiation at 700 W and 45 KHz for 2.5 h at 35 °C.4.We synthesized the Er³⁺:YAlO₃/WO₃-Ta_xNb_yO₅?x+y=2?composite catalytic materials by hydrothermal and ultrasonic dispersion method,and characterized the catalysts.We used the catalysts to degrade the aqueous solution of pethidine hydrochloride.The results showed that Er³⁺:YAlO₃/WO₃-Ta_0.5Nb_1.5O₅ could degrade 86.64 % of pethidine hydrochloride after irradiation at 700 W and 45 KHz for 2.5 h at 35 °C.The above-mentioned sonocatalysis materials designed and synthesized are stable and environment-friendly,and can be reused.The established sonocatalysis method for degrading drugs is simple,and is promising to be used in the field of harmless treatment of drugs.