Visible Photo-catalyst CdS:Preparation By Slow Precipitation-Water Thermosetting And Application For The Degradation Of Sulfameter

In today’s health care and animal husbandry,the use of antibiotics has brought people more convenience.However,at the same time,with the large discharge of antibiotic wastewater into aquatic and terrestrial ecosystems,it poses an incalculable hazard to the environment and human health.Antibiotic contamination has become an environmental issue that people are increasingly concerned about.Photochemical processes play an important role in the conversion and degradation of pollutants in water bodies.Visible light photocatalysis as a treatment of antibiotic contamination belongs to economic green technology and is one of the most promising approaches.In this project,the visible light catalyst cadmium sulfide(CdS)was prepared by a slow precipitation-water thermosetting method,and the effects of pyrolysis temperature,material ratio and calcination on the catalyst were discussed.XRD,TG and UV-vis absorption spectra were used to characterize the crystal shape,thermal stability and visible light spectral absorption area of the catalyst.Degradation of the antibiotic Sulfameter(SM)by photocatalytic degradation explored the operating conditions for this application.The degradation products of the antibiotic were deduced by high performance liquid chromatography-mass spectrometry(HPLC-MS)combined with chemical calculation,and the photodegradation pathway was analyzed.The research results in this work show that the visible light catalyst CdS prepared by the slow precipitation-water thermosetting method has higher visible light driving activity.In addition,the X-ray diffraction pattern indicates that the hydrothermal temperature and the calcination temperature affect the crystal form of the catalyst synthesis.When the hydrothermal temperature is 180℃ and calcination temperature is 300℃ the crystalline form of the catalyst is more stable and the catalytic efficiency is more stable.And it can be analyzed that the self-made catalyst CdS is a heterogeneous catalyst mainly composed of hexagonal crystal structure.According to the UV-vis absorption spectrum,it can be seen that the visible light absorption spectrum range of the homemade catalyst CdS is larger than that of the commercial CdS visible light region.In the application experiments,the photodegradation rate of self-made visible light catalyst CdS on Sulfameter is as high as 80%,while the commercial CdS degradation rate is only about 33%.In addition,based on HPLC/SI-MS analysis and density functional theory,the photodegradation pathway of Sulfameter was deduced,and the main reactions such as ring opening,ammoxidation,and hydroxylation occurred during the photodegradation of Sulfameter.In summary,this visible-light-driven catalyst CdS is effective for the degradation of antibiotic Sulfameter,and the results provide a scientific basis for assessing antibiotic transformation in water.