Preparation Of Zirconia-based Composites And Their Photocatalytic Properties

Printing and dyeing wastewater is one of the sources of polluting water resources,many scholars and experts use various methods to deal with printing and dyeing wastewater.As an efficient and environmentally friendly wastewater treatment technology,photocatalytic technology uses the photochemical process of materials to treatwastewater.Zr O₂is also a very useful semiconductor in photocatalysis.However,due to its wide band gap,low quantum catalyticefficiency and only response to UV light,factors that limit its use of solar energy,affected the photocatalytic performance of zirconia.In order to solve the problem described above,this paper mainly studies the composite of zirconia with g-C₃N_4,Reduced grapheneoxide（r GO）and Zn O respectively,and To explore the photocatalytic ability of Methylene blue（MB）solution by changing the contents of g-C₃N₄,Reduced graphene oxide（r GO）and Zn O in the composite.The specific experimental results are as follows:（1）ZrO₂/g-C₃N₄composite was prepared by the combination of precipitation method and heat treatment with zirconium oxychloride octahydrate and melamine as raw materials,and analyzed by X-ray diffraction（XRD）and other methods.The results of the photocatalytic degradation of MB showed that when the content of g-C₃N₄was 9%of the composite a solution of 10 mg/L MB couldbe completely decomposed under 60 minutes of light with the help of 0.5m L H₂O₂.In the subsequent degradation experiments of MB solution containing salt,it was found that when the content of g-C₃N₄was 1%,MB containing a small amount of Na Cl could be completely decomposed under certain conditions.The Zr O₂/g-C₃N₄composite still has good photocatalytic performance after five experimental periods.（2）ZrO₂/rGO composites were prepared by the combination of precipitation and heat treatment.Materials such as zirconium oxychloride octahydrate andreduced graphene oxide are used as raw materials.It was analyzed by various methods such as XRD.The results of photocatalytic degradation experiments on MB solution showed that when r GO is present in1%of the composite,a 10 mg/L MB solution decomposes completely under 60 minutes of light and with the aid of 0.5m L H₂O₂.However,when a small amount of Na Cl was added into MB solution,the degradation time was shortened to 40min.Moreover,MB solutions with different concentrations of Na Cl can be completely degraded within a certain period of time.Subsequently,it was found that when the p H value of the solution was 9 and the experimental time was 10min,the degradation rate of MB could reach 96.5%.On the basis of these results,five times of repeated experiments were conducted on Zr O₂/r GO,and it was found that its photocatalytic performance was still very good.（3）ZrO₂/ZnO composites were prepared by the combination of precipitation and heat treatment using zirconia octahydrate and zinc hydroxide as raw materials.XRD and other methods were used for analysis.The photocatalytic degradation of MB was studied.When the content of Zn O reached 2%of that of the composite,under the action of 0.5m L H₂O₂,the experimental time of 60min could completely degrade 10mg/L MB solution.However,at the same time,the addition of a small amount of Na Cl to the MB solution has an inhibitory effect The photocatalytic performance of samples with Zn O content reaching 1%of Zr O₂/Zn O composites was improved.,and MB solution was completely degraded within 40min.With the increase of salt content,the photocatalytic properties ofdifferent samples are affected.The photocatalytic property of the sample remained high after the experiments were repeated for 5times.In this paper,zirconia and its composites were prepared by precipitationmethod combined with heat treatment.It was found that the composite material had high photocatalytic degradation ability for MB solution or MB solution containing Na Cl.At the same time,Zr O₂/r GO composite also has excellent photocatalytic properties for MB solution with high p H.These experimental results provide a new inspiration for the treatment of printing and dyeing wastewater.