LaNiO₃ Perovskite Catalyst Modified By Solid Phase Grinding And The Degradation Of Some Water Pollutants

Because of the advantages of low cost flexible structure and adjustable structure,perovskite metal oxides have bright application prospect in energy and related fields,and their application is also very valuable.However,the single perovskite material has large particle size and small specific surface area,so its activity in the catalytic reaction is limited to some extent,which hinders the development of this kind of material to some extent.Therefore,it is of great significance to improve the catalytic performance of perovskite materials by doping with organic and inorganic elements.In this paper,LaNi03 doped organic carbon and nitrogen composite perovskite catalyst(LNCN)was synthesized in situ by solid-phase grinding method and its catalytic performance for the degradation of humic acid wastewater was investigated.Secondly,the composite perovskite material(LNCN/Ag(2/1))was prepared by impregnation method on the surface of LNCN catalyst.The photocatalytic performance of this material against antibiotic wastewater was studied.Finally,LNCN materials were composite with four diferent metal oxides to compare the performance of the materials modified by different metal oxides in photocatalytic degradation of dyeing wastewater.The main findings are as follows:(1)The LNCN catalyst was synthesized by in-situ doping organic carbon and nitrogen-modified LaNiO3 perovskite by solid-phase grinding method.Through XRD,SEM,TEM,BET and other characterization analysis,it was found that the doped and modified The LNCN catalyst is irregularly shaped rod-shaped particles;LaNiO3,La2O2CO3 and NiO can be found in the composite material to form an obvious heterojunction structure;due to the doping of organic elements,the composite material has a larger specific surface area than the pure phase LaNiO3 material.Secondly,when treating humic acid wastewater,the modified LNCN material has better catalytic performance.The degradation of 30 mg/L humic acid wastewater can be completed within 45 minutes using 10 mg catalyst.The recycling experiment shows that the material has good stability,with 90%degradation effect after 4 times of use.At the same time,the light-dark contrast experiment proved that light is not the main driving force in the degradation process,and light only has the effect of accelerating and improving.(2)Using LNCN as the basic material,the LNCN/Ag(x)composite was synthesized by impregnation method,and the apparent influence of different loading of Ag on the catalyst and the influence on the photocatalytic degradation performance of chlortetracycline hydrochloride and doxycycline hydrochloride were explored.The experimental results show that the addition of elemental Ag increases the specific surface area of the catalyst and at the same time increases the photosensitivity,thereby improving the photocatalytic performance of the material.When m(Ag):m(LNCN)=1:2,the composite material prepared has optimal catalytic performance.The best photocatalytic degradation conditions are as follows:under 1000 W xenon lamp irradiation,40 mg of LNCN/Ag(2/1)catalyst can degrade 80 mL of antibiotic wastewater with a concentration of 40 mg/L,and the degradation rate of chlortetracycline hydrochloride and doxycycline hydrochloride Both can reach 99%.(3)Using titanium dioxide,aluminum oxide,copper oxide and metal salt Al(NO3)3·9H2O and LNCN catalyst respectively,in-situ solid-phase grinding and calcination in a muffle furnace to prepare four different metal oxide composite modified Perovskite materials.The photocatalytic performance of the composite material was tested by two printing and dyeing wastewaters,neutral red and malachite green dye.The experimental results showed that the LNCN/TiO2 composite material synthesized by loading TiO2 had the best photocatalytic degradation effect.The optimal conditions for degrading neutral red wastewater are:1000 W xenon lamp as the light source,80 mL of 30 mg/L neutral red solution as the degradation substrate,and the degradation rate can reach 90%within 120 min using 50 mg catalyst;malachite green wastewater The optimal degradation conditions are:40 mg of catalyst,using 1000 W xenon lamp for 120 min,the degradation rate of 80 mL malachite green wastewater with an initial concentration of 15 mg/L can reach 80%.The material characterization test shows that the composite of TiO2 increases the specific surface area of the material,and at the same time changes the band gap of the material,so it is more conducive to photocatalytic degradation.