Ag_2CO_3/Ag/g-C_3N_4 Z-型异质结的制备及可见光催化降解RhB  

Preparation of Ag_2CO_3/Ag/g-C_3N_4 Z-scheme Heterostructure and Photocatalytic Degradation of Rhodamine B Under Visible Light

作　　者：王娟 王国宏 孙玲玲 WANG Juan;WANG Guo-hong;SUN Ling-ling(Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Hubei Normal University,Huangshi 435002,Hubei,China;College of Chemistry and Chemical Engineering,Hubei Normal University, Huangshi 435002,Hubei,China;Institute for Advanced Materials, Hubei Normal University,Huangshi 435002,Hubei,China)

机构地区：[1]湖北师范大学污染物分析与资源化技术湖北省重点实验室,湖北黄石435002 [2]湖北师范大学化学化工学院,湖北黄石435002 [3]湖北师范大学先进材料研究院,湖北黄石435002

出　　处：《材料工程》2018年第9期39-45,共7页Journal of Materials Engineering

基　　金：湖北省自然科学基金项目(2016CKC776);污染物分析与资源化技术湖北省重点实验室开放基金(PA20170210)

摘　　要：通过煅烧处理和沉淀反应合成以Ag纳米粒子为电子媒介的Z-型光催化剂Ag_2CO_3/Ag/g-C_3N_4。在可见光照射下,降解RhB评价Ag_2CO_3/Ag/g-C_3N_4复合物的光催化活性。结果表明:Ag2CO3/Ag/g-C3N4样品显示出比纯Ag_2CO_3和g-C_3N_4更强的光催化活性,当g-C3N4与Ag_2CO_3/Ag质量比为20%时,复合物呈现出最好的光催化性能,这归因于在Ag_2CO_3和g-C_3N_4间形成的Z-型异质结构,其有效促进电子转移速率和光生电子-空穴的分离。Z-型异质结构扩展了可见光吸收波长范围(从450nm到670nm),这是由于Ag纳米粒子表面离子共振的结果。捕获实验证实,在光催化降解RhB反应中,·O_2^-和空穴h^+是主要活性物质,·OH是次要活性物质,并提出了增强光催化活性的机理。The highly efficient Z-scheme photocatalyst Ag 2CO 3/Ag/g-C 3N 4 with Ag nanoparticles,as an electron mediator,was fabricated by a simple calcinations-precipitation reaction.Photocatalytic experiments of the as-prepared samples were tested by the photocatalytic oxidation degradation of RhB aqueous solution.The results show that Ag 2CO 3/Ag/g-C 3N 4 composites exhibit enhanced photocatalytic activity,compared with Ag 2CO 3 and g-C 3N 4.The composites exhibit the highest photocatalytic performance,when the mass ratio of g-C 3N 4 to Ag 2CO 3/Ag is 20%,which is attributed to the formation of Z-scheme heterojunction structure between Ag 2CO 3 and g-C 3N 4,thus accelerating electron transfer rate and separating efficiently the photo-generated electron-hole pairs.Meanwhile,the Z-scheme heterojunction structures extend the wavelength range of visible light absorption(from 450nm to 670nm)due to the surface plasma resonance(SPR)of Ag nanoparticles.The trapping experiment results confirm that·O-2 and h+are main active species,·OH plays a relatively minor role in the decomposition of RhB.A possible mechanism for enhanced photocatalytic activity of Ag 2CO 3/Ag/g-C 3N 4 heterojunction photocatalyst is proposed.

关 键 词：Ag2CO3/Ag/g-C3N4 Z-型光催化剂 可见光 光催化活性 

分 类 号：O643[理学—物理化学]