Preparation And Application Of Ag₃PO₄/g-C₃N₄/GO Photocatalyst

“Green water and green mountains are golden mountains and silver mountains".As an indispensable resource for production and life,water is undering various environmental problems because of economic development.Water pollution is the focus of the current world environmental pollution control.China is a big country in printing and dyeing and textiles.The chromaticity of printing and dyeing wastewater is high,and COD of the content of organic matter is high.Photocatalytic technology has high degradation efficiency,less pollution in the degradation process,and low energy consumption.It is used by researchers to catalyze the degradation of organic pollutants in water,atmospheric catalytic oxidation,photocatalytic hydrolysis to produce hydrogen,and photocatalytic reduction of CO2.However,further studies have found that most photo-generated electron-hole pairs of catalysts have a problem of low separation rate.Therefore,further studies have found that most catalysts have low separation rates for e-and h-.Therefore,researchers are committed to modifying the semiconductor photocatalyst to expand its light response range so that it can absorb more Light reduces the recombination rate of e-and h+,and the photocatalytic performance is improved.Both Ag₃PO₄ and g-C₃N₄ have the ability to remove organic pollutants in water under visible light.However,g-C₃N₄ prepared by ordinary methods has the disadvantages of large specific surface area,weak visible light response,and low separation rate of photogenerated e-and h+.However,Ag₃PO₄ is prone to agglomeration and its own electrons are easily captured by Ag+.In response to these problems,this article developed a method for preparing g-C₃N₄ with high specific surface area,and formed Ag₃PO₄/g-C₃N₄ by forming a heterojunction with Ag₃PO₄.At the same time,GO was used as a carrier to prepare Ag₃PO₄/GO and Ag₃PO₄/g-C₃N₄/GO composite photocatalysts.Also through various means such as characterization,the morphology and light absorption properties of the composite materials were analyzed,and organic dyes were used as simulated printing and dyeing wastewater.Discuss its photocatalytic degradation activity and mechanism,as follows:1.Ag₃PO₄/GO composite was prepared via loading with Ag₃PO₄ nanoparticles on GO matrix by in situ precipitation method and was characterized by SEM and XRD.The results showed that Ag₃PO₄ nanoparticles were spherical and distributed uniformly on the GO thin films.The photocatalytic degradation of RhB by Ag₃PO₄/GO composite showed a degradation rate of 95.7%,60 min under visible light irradiation.The degradation rate of RhB still reach 80.7%after four-time reuse of the same catalyst,indicating an excellent stability.The degradation mechanism study shows that h+ is the main active substance.2.Successfully prepared g-C₃N₄ with high specific surface area by pyrolysis method.After characterization,it is found that the prepared g-C₃N₄ has a great improvement in morphology and structure.Detailed characterization techniques show that it has a better nanosheet structure and a thinner thickness.In MB degradation experiments,it is shown that g-C₃N₄ with high specific surface area significantly improves the photocatalytic degradation performance,and the increase in specific surface area greatly increases the utilization rate of g-C₃N₄ light source.At the same time,the medicine required by the preparation method is cheap and easy to obtain,the preparation process does not require secondary treatment,the operation is simple,and it is suitable for practical applications.3.The prepared Ag₃PO₄/g-C₃N₄ binary composite photocatalyst was prepared by the in-situ precipitation method with g-C₃N₄ with high specific surface area.After XRD,SEM,TEM,UV-Vis DRS and PL,it was found that pure Ag₃PO₄ presents a spherical nano-particle structure and is prone to agglomeration,while g-C₃N₄ is a single-layer flake-like structure,and Ag₃PO₄ and g-C₃N₄ are organically combined to disperse the spherical Ag₃PO₄ nanoparticles.The specific surface area of the catalyst is greatly increased,The number of active sites also increases.When the amount ratio of Ag₃PO₄/g-C₃N₄ is 1.0:0.7,the photocatalytic activity of Ag₃PO₄/g-C₃N₄ composite is the best.30 min under visible light,the degradation rate of MB reaches 100%.The catalyst has good stability by repeatability tests,and the degradation rate of MB still reaches 85.24%after repeated use for four times.The capture agent experiment shows that the main active substances that degrade MB are h+and e-,and the Z-type reaction mechanism is proposed.After HPLC and COD experiments,it is proposed that MB may be degraded into CO2 and H2O.4.The Ag₃PO₄/g-C₃N₄/GO ternary composite material was prepared by in-situ precipitation method by adjusting the amount of GO added.It was found through XRD,SEM,UV-Vis DRS and PL characterization,and the addition of GO was adjusted.It greatly improves the dispersion of spherical Ag₃PO₄ nanoparticles,and the resulting ternary composite material also has better visible light response,thus exhibiting good photocatalytic activity.The photocatalytic degradation rate of MB reached more than 85%after 10 min under visible light.The Ag₃PO₄/g-C₃N₄/GO ternary photocatalyst has good stability.Repeatability tests show that the degradation rate still reaches 91.23%after repeated use for four times.The capture agent experiment shows that the main active substances that degrade MB are h+and e-,and the addition of GO does not change the Z-type response mechanism.The experiment of degrading the actual printing and dyeing wastewater showed that the COD removal rate reached 89.51% after 60 min under visible light.