Photocatalytic Degradation Of Toluene By Modified Graphite Phase Carbonitride

The non-metallic material g-C3N4 has a special electro-optical structure,good chemical stability,and can degrade toluene in the indoor environment under photocatalytic conditions,and has potential application prospects in improving indoor air quality.However,pure g-C3N4 has a small specific surface area,more lattice defects,and photogenerated electron-hole pairs are easy to recombine,resulting in low efficiency of photocatalytic degradation of toluene,which limits its practical application.In this study,the g-C3N4 material was modified by metal doping and semiconductor compounding to obtain a photocatalytic material capable of efficiently degrading toluene.The main research contents are as follows:The modified g-C₃N₄ photocatalytic material was prepared by doping Fe（NO₃）₃ with g-C3N4.The prepared samples were characterized by XRD,SEM,TEM and photocatalytic degradation of toluene.The results of analysis and characterization show that the introduction of Fe（NO3）3 reduces the band gap energy of g-C3N4 and makes the absorption range of visible light wider.Analysis of experimental data shows that Fe-doped samples have better photocatalytic degradation of toluene than pure g-C₃N₄,and the optimum doping amount of Fe is 15%,and the degradation effect is up to 65%.The photocatalytic material of Bi₂WO₆-CN was synthesized by hydrothermal method to prepare Bi₂WO₆ and ball-milled.The composite samples were characterized by XRD,SEM,TEM and photocatalytic degradation of toluene.The analysis and characterization results show that the composite has a larger specific surface area and a stronger adsorption capacity,and the newly formed heterojunction significantly broadens the visible light absorption range.Analysis of the experimental data shows that the best photocatalytic degradation of toluene can reach 72%when the composite amount of Bi2WO6 is 60%,and the photocatalytic degradation rate after compounding is obviously improved.The FeCN-Bi2WO6 photocatalytic material was synthesized by the addition of15%-FeCN in the preparation of Bi2WO6 by hydrothermal method.The ternary composite samples were characterized by XRD,SEM,TEM and photocatalytic degradation of toluene.The analysis and characterization results show that the ternary composite has a specific surface area of 64.479 m²/g,and the adsorption capacity is the best.The layer g-C₃N₄ and the spherical Bi₂WO₆ are tightly combined,the visible light absorption range is the widest,and the band gap is the narrowest,which greatly improves the catalysis.active.Analysis of experimental data shows that when the FeCN composite ratio is 60%,the efficiency of photocatalytic degradation of toluene can reach 86%,which is higher than other modified materials.On the basis of the photocatalytic activity research,the results show that·O_2-plays an important role in promoting the photocatalytic efficiency,and the type II carrier transfer mechanism is proposed.The photocatalytic repeated experiments show that the composite has good stability.And recyclability.