摘要
采用原位沉淀法将高温煅烧制得的TiO_(2)/g-C_(3)N_(4)复合物负载到Ag_(3)PO_(4)上,制备出三元异质结TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)复合光催化剂,并用于降解罗丹明B(RhB)。通过X射线衍射(XRD)、扫描电镜(SEM)、紫外-可见漫反射光谱(UV-vis DRS)等测试方法对该异质结的组成、微观结构和理化性质等进行表征与分析。研究结果表明,在TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)复合光催化剂中,粒径约为100 nm的TiO_(2)纳米颗粒均匀地负载于g-C_(3)N_(4)和Ag_(3)PO_(4)表面,材料的吸收带边发生红移。以RhB为模拟污染物,在可见光照射下TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)异质结表现出优异的光催化活性。可见光照射7 min后,TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)复合光催化剂对RhB的降解率可达99%,明显优于纯g-C_(3)N_(4)、TiO_(2)、Ag_(3)PO_(4)及二元复合物,并且在重复使用5次后其光催化降解率仍保持在92%以上,表明TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)异质结具有较强的光催化活性和稳定性。通过捕获实验探究其光催化机理,三元异质结中具有π共轭结构的g-C_(3)N_(4)有助于电荷转移,在可见光照射下,异质结中的光生电子积累在g-C_(3)N_(4)导带,光生空穴积累在Ag_(3)PO_(4)和TiO_(2)价带,从而促使e^(-)-h^(+)对分离,提高了光生载流子的分离效率,此复合光催化剂的主要反应活性物种为光生空穴(h^(+))和超氧自由基(·O_(2)^(-)),而电子(e^(-))的作用相对较小。
Ternary heterojunction TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)photocatalyst,loading the calcinated TiO_(2)/g-C_(3)N_(4)composite on the surface of Ag_(3)PO_(4),was successfully prepared by insitu precipitation for the degradation of Rhodamine B(RhB)dye.The composition,microstructure and physicochemical properties of the samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),ultraviolet visible diffuse reflectance spectroscopy(UV-vis DRS).The results showed that TiO_(2)nanoparticles with the particle size of about 100 nm were uniformly supported on the surface of g-C_(3)N_(4)and Ag_(3)PO_(4)in TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)photocatalyst,and the absorption edge of the heterojunction underwent a red shift.Excellent photocatalytic activity of TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)under visible light irradiation was demonstrated by degrading RhB dye.After exposure to visible light for 7 min,the degradation rate of RhB by TiO_(2)/g-C_(3)N_(4)/Ag_(3)PO_(4)photocatalyst could reach 99%,which was obviously higher than that of pure g-C_(3)N_(4),TiO_(2),Ag_(3)PO_(4)and binary complex,and its photocatalytic degradation rate remained above 92%after repeated use for 5 times,indicating its strong photocatalytic activity and excellent stability.Moreover,the photocatalytic degradation mechanism was explored through the capture experiments.In this ternary heterojunction,g-C_(3)N_(4)withπ-conjugate structure facilitated charge transfer.Under the irradiation of visible light,the photogenerated electrons accumulated in the conduction band of g-C_(3)N_(4),and the photogenerated holes accumulated in the valence band of Ag_(3)PO_(4)and TiO_(2),thus e--h^(+)pairs were separated effectively to improve the separation efficiency of photogenerated carriers.The primary active species of photocatalyst were photogenerated holes(h^(+))and superoxide free radicals(·O_(2)^(-)),while e-basically had no effect.
作者
朱建君
刘佩婷
韩雯博
王晶
ZHU Jianjun;LIU Peiting;HAN Wenbo;WANG Jing(College of Chemistry and Chemical Engineering,Xinyang Normal Univeristry,Xinyang 464000,China)
出处
《无机盐工业》
北大核心
2025年第5期116-124,共9页
Inorganic Chemicals Industry
基金
河南省高等学校重点科研项目(24B150034)。
关键词
磷酸银
异质结
光催化
罗丹明B
Ag_(3)PO_(4)
heterojunction
photocatalysis
Rhodamine B
作者简介
朱建君(1979-),女,博士,副教授,主要研究方向为光催化材料及应用,E-mail:chemzhujj@126.com。
