| Industrial development and progress not only bring convenience to human beings,but also destroy the balance of the natural environment.In order to solve the sewage problem,many scientists have put forward a variety of solutions,but all of them have some drawbacks.As the technology evolved,researchers discovered that the photocatalysis of semiconductors could be used to degrade wastewater,that is,to clean it up without producing the rest of the waste,but only by consuming sunlight.The optical properties of TiO2 are the current research hotspot,but pure TiO2 can only absorb ultraviolet light,the utilization efficiency of sunlight is only one twentieth,the photocatalytic efficiency is very low.Studies have shown that doping TiO2 with metal elements can broaden its absorption spectrum and improve the utilization of visible light.To this end,this subject studied the modification of Au doped TiO2,and combined with image processing and FPGA technology,designed a sewage detection system.For the study on the properties of Au doped anatase TiO2,Material Studio8.0 was used to establish the til-maumo2 Material calculation model,the first-principles calculation based on the HSE06 framework of the exchange association functional theory was adopted,and the CASTEP module was used for calculation.The main research contents of this paper are:1)energy band gap:from the microscopic perspective,the mechanism of photocatalysis is analyzed,and the property changes of crystals are studied;2)density of state:by analyzing the density of state of Au doped anatase TiO2,the contribution of each element to the crystal band structure and the change of electron distribution were studied.3)lattice structure:the influence of optical properties of anatase TiO2 crystals was studied by analyzing the changes of doping lattice structure;4)doping concentration:the optimal optical properties of anatase TiO2 crystal can be obtained by studying the appropriate doping concentration and selecting the appropriate Au doping concentration.It is found that the change of lattice structure has an effect on the photocatalytic performance,but it is not the main reason.Au doping can reduce the band gap width of the crystal and cause red shift of the light absorption coefficient of TiO2.When the doping concentration is low,the absorption range of visible light is obviously increased,while when the doping concentration is high,the absorption range of visible light is not only increased,but also the absorption intensity is enhanced,and the redshift phenomenon is more obvious,which has certain guiding significance for improving the application in the degradation of polluted water and light.In order to detect the final sewage treatment effect,an image processing wastewater detection system based on FPGA is designed theoretically.Using FPGA as the main processor,the sewage image collected by the waterproof camera was digitized for a series of processing.According to the different reflection characteristics of water and pollution particles to light,the collected sewage image was processed by the algorithm,and the concentration value of suspended particles in sewage was calculated.Then,the calculated results are reported to the operator,so as to control the automatic treatment of sewage.Through the calculation and analysis of Au doped TiO2 light absorption characteristics,it is concluded that Au doped TiO2 can improve the light absorption spectrum width and greatly improve the light utilization efficiency.Therefore,the photodegradation capacity of TiO2 on sewage can be improved by doping Au.At the same time,in order to facilitate the real-time detection of sewage treatment effect,the image processing method based on FPGA is used to realize detection and control under the condition of no contact with sewage,which provides a certain reference for sewage treatment and detection. |
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