Preparation Of FeOOH/g-C₃N₄ Visible Light Catalyst And The Study On The Degradation Of PNP And Carmine Wastewater

There are many kinds of organic pollutants in water,some of which are difficult to degrade,widely distributed and easy to be enriched,which have brought great harm to the environment and health of human.Semiconductor photocatalytic technology has shown great potential in the removal of organic pollutants due to it’s low energy consumption,strong redox ability and mild reaction conditions,and has become a research hotspot.In order to give full play to the advantages of this technology,the most important thing is to design and prepare photocatalyst with high performance.In this study,FeOOH/g-C3N4 photocatalyst was prepared by thermal polycondensation and coprecipitation method,and the photo-Fenton-like reaction system with PNP and carmine in water as the main target pollutants was established,and it’s visible light photocatalytic performance and mechanism of action were studied.The optimal preparation conditions of g-C3N4 prepared by thermal polycondensation method are as follows:calcination at 600℃ for 4 h;The optimum conditions for the preparation of FeOOH/g-C3N4by the coprecipitation method were 0.3 Fe source.The prepared g-C3N4 and FeOOH/g-C3N4 were characterized by XRD,SEM,EDS,BET and UV-Vis.The experimental results showed that FeOOH was successfully doped onto the surface of g-C3N4.The microstructure shows the ultrathin nanosheet with rough surface.The specific surface area is greatly increased and a suitable pore structure is formed.The visible light catalytic performance of FeOOH/g-C3N4 under optimized preparation conditions was studied.The results show that the degradation rate of PNP can reach 92%under the simulated visible light irradiation for 2 h,and the photocatalytic rate of the quasi-first order reaction kinetics is 0.02079 min-1,and it has good recycling and stability(the degradation rate is still nearly 80%after repeated 5 times).The degradation rate of carmine can reach 98%under simulated visible light irradiation for lh,and the photocatalytic reaction rate of quasifirst-order reaction kinetics is 0.03841 min-1,and it has good adaptability under acidic conditions.The mechanism of FeOOH/g-C3N4 visible light catalytic degradation of target pollutants was systematically investigated.According to the capture experiment of active species,the main active species of the photocatalytic system are ·OH and ·O2-.