Study On Performance Of Inorganic Micro-Nano Hollow Spheres By Hydrothermal Method

Inorganic oxide functional materials have been widely used in many fields.It is very important to improve the properties of inorganic oxide materials through constructing inorganic oxide as a hollow sphere structure with low density and high specific surface area.At present,all kinds of inorganic micro-nano hollow spheres have been widely applied in the many fieldssuch as photocatalyst,battery electrodes,gas sensors and other related fields.Single elementinorganic micro-nano hollow spheres such as ZnO,NiO cannot achieve the ideal performance due to its internal energy band or crystal structure limitations,but metallic elements doping inorganic micro-nano hollow spheres can enhance the correlation properties even extend its application in other fields.Zinc oxide?ZnO?hollow spheres and nickel oxide?NiO?hollow spheres and zinc?Zn?-doped nickel oxide?NiO?hollow spheres were prepared via a facile one-step hydrothermal method in this paper.Samples were characterized by Fourier transform infrared spectroscopy?FT-IR?,X ray diffraction?XRD?,UV-Vis diffuse reflectance?UV-DRS?analysis,luminescence spectroscopy?PL?,X-ray photoelectron spectroscopy?XPS?,scanning electron microscopy?SEM?,transmission electron microscopy?TEM?.The effects of the amounts of polyvinylpyrrolidone on the morphology of the hollow spheres were investigated.In the same time,research the visible light photocatalytic degradation of organic dye performance of ZnO hollow spheres and the electrochemical performance of ZnO hollow spheres and NiO hollow spheres and Zn doped NiO hollow spheres.The main research results are as follows:?1?ZnO hollow spheres with diameter of 2?m and shell thickness around 50nm were prepared via a facile one-step hydrothermal method by using zinc nitrate hexahydrate as raw materials,considering ures as precipitating agent and regarding polyvinylpyrrolidone as surface active agent through subsequent calcination process?calcination temperature 500??.The effects of the amounts of polyvinylpyrrolidone on the morphology of the hollow spheres were investigated.The results indicate that when the amount of polyvinylpyrrolidone is 0.13g,the morphology of hollow spheres is appropriate.H₂O₂ is regarded as promoter.The photocatalytic activities of 5mL H₂O₂,ZnO powder,5mL H₂O₂+ZnO powder?5mL H₂O₂+ZnO hollow spheres were estimated by the degradation process of dye methyl orange?MO?under irradiation of visible light,results show that the degradation effect of ZnO hollow spheres>ZnO powder.The ZnO hollow spheres degradation ratio of MO achieved a maximum?99%?after irradiation for160 min and the ZnO powder only achieved a maximum?45%?after irradiation for 225min.Used cyclic voltammetry?CV?,constant current charge discharge test?GCD?and AC impedance test?EIS?electrochemical test methods characterized the electrochemical performance of ZnO powders and the different amount of PVP ZnO hollow spheres.The results indicate that when the amount of polyvinylpyrrolidone is 0.13g,the electrochemical activity of hollow spheres is highest.The results of CV shown that in the5mV/s scan rate,capacity of ZnO hollow spheres without PVP was 68.92F/g,higher than37.32F/g of ZnO powder.Subsequently,ZnO hollow spheres of different doped amount of PVP for electrochemical test,the results of CV shown that ZnO hollow spheres with0.13g PVP in 5mV/s scan ratecan achieved the maximum capacity of 241.6F/g,the GCD test can also be obtained in charge discharge current density of 0.5A/g,the capacity of ZnO hollow spheres with 0.13g PVP was 137.467F/g,and the 1000 charge/discharge cycles after the capacitance retention rate was 70%.?2?NiO hollow spheres with diameter of 2?m and shell thickness around 50nm were prepared via a facile one-step hydrothermal method by using nickel sulfate hexahydrate as raw materials,considering urea as precipitating agent and regarding polyvinylpyrrolidone as surface active agent through subsequent calcination process?calcination temperature 500??.The effects of the amounts of polyvinylpyrrolidone on the morphology of the hollow spheres were investigated.The results indicate that when the amount of polyvinylpyrrolidone is 0.13g,the morphology of hollow spheres is appropriate.Used cyclic voltammetry?CV?,constant current charge discharge test?GCD?and AC impedance test?EIS?electrochemical test methods characterized the electrochemical performance of NiO powders and the different amount of PVP NiO hollow spheres.The results indicate that when the amount of polyvinylpyrrolidone is0.13g,the electrochemical activity of hollow spheres is highest.The results of CV shown that in the 5mV/s scan rate,capacity of NiO hollow spheres without PVP was 62.4F/g,higher than 41.44F/g of NiO powder.Subsequently,NiO hollow spheres of different amount of PVP for electrochemical test,the results of CV shown that NiO hollow spheres with 0.13g PVP in 5mV/s scan ratecan achieved the maximum capacity of294.32F/g,the GCD test can also be obtained in charge discharge current density of0.5A/g,the capacity of NiO hollow spheres with 0.13g PVP was 204.68F/g,and the 1000charge/discharge cycles after the capacitance retention rate was 80%.?3?NiO hollow spheres of different doped amount of Zn?Zn:Ni=1%,2%,4%?with diameter of 2?m and shell thickness around 50nm were prepared via a facile one-step hydrothermal method by using nickel sulfate hexahydrate as raw materials,considering urea as precipitating agent and regarding polyvinylpyrrolidone as surface active agent through subsequent calcination process?calcination temperature 500??.The results indicate that when the amount of Zn is 2%,the morphology of hollow spheres is appropriate.Used cyclic voltammetry?CV?,constant current charge discharge test?GCD?and AC impedance test?EIS?electrochemical test methods characterized the electrochemical performance of the different amount of Zn droped NiO hollow spheres.The results of CV shown that 2%Zn-NiO hollow spheres in 5mV/s scan ratecan achieved the maximum capacity of 357.08F/g,the GCD test can also be obtained in charge discharge current density of 0.5A/g,the capacity of 2%Zn-NiO hollow spheres was255.28F/g,and the 1000 charge/discharge cycles after the capacitance retention rate was80%.