热剥离处理对氮化碳2D纳米片结构和光催化性能的影响  

Effect of thermal exfoliation treatment on the structure and photocatalytic performance of carbon nitride 2D nanosheets

作　　者：肖柯 李伟超 周烈兴[2] 解林坤 柴希娟 XIAO Ke;LI Weichao;ZHOU Liexing;XIE Linkun;CHAI Xijuan(School of Materials Science and Engineering, Southwest Forestry University, Kunming 650224, China;Analysis and Testing Research Center, Kunming University of Science and Technology,Kunming 650093 ,China)

机构地区：[1]西南林业大学材料科学与工程学院,昆明650224 [2]昆明理工大学分析与测试研究中心,昆明650093

出　　处：《功能材料》2022年第1期1090-1096,共7页Journal of Functional Materials

基　　金：国家自然科学基金项目(31960297,31660179,31760184)。

摘　　要：石墨相氮化碳(g-C_(3)N_(4))因制备成本低、无毒无害、物化性能稳定等优点而备受关注,然而,不同前驱体制得的g-C_(3)N_(4)的产率和光催化活性也不同。分别以尿素、二氰胺、三聚氰胺为前驱体,采用热剥离法制备了氮化碳2D纳米片。系统考察了不同前驱体及热剥离温度对氮化碳结构和光催化性能的影响。结果表明,以尿素为前驱体不经热剥离可以直接制得光催化性能优异的g-C_(3)N_(4)2D纳米片,其对亚甲基蓝的降解率最高,为60%,但其产率极低,约2%~3%。以二氰胺和三聚氰胺为前驱体制得的氮化碳再经热剥离处理可得到结构疏松、光催化性能优异的2D g-C_(3)N_(4)纳米薄片,其产率可分别高达32.5%和36.8%。其中,以双氰胺为前驱体在580℃处理4 h后制得的2D纳米薄片g-C_(3)N_(4)光催化活性最优,其对亚甲基蓝的降解效率可达91.1%,较未剥离样品提高了40%。经4次循环使用后,其降解率仍可保持在90%,表现出良好的稳定性和重复实用性。Graphite carbon nitride(g-C_(3)N_(4))has attracted much attention due to its advantages such as low preparation cost,non-toxic and harmless,and stable physicochemical properties.However,the yield and photocatalytic activity of g-C_(3)N_(4) obtained from different precursor systems are also different.In this study,urea,dicyanamide,and melamine were used as precursors to prepare carbon nitride 2D nanosheets by thermal stripping method,respectively.The effects of different precursors and thermal exfoliation temperature on the structure and photocatalytic performance of carbon nitride were systematically investigated.The results show that g-C_(3)N_(4)2D nanosheets with excellent photocatalytic performance can be directly prepared with urea as the precursor without thermal exfoliation,and the degradation rate of methylene blue is the highest,which is 60%.But its yield is extremely low,about 2%-3%.Carbon nitride prepared with dicyandiamide and melamine as precursors can be subjected to thermal exfoliation treatment to obtain 2D g-C_(3)N_(4) nanosheets with a loose structure and excellent photocatalytic performance.The yields can be as high as 32.5%and 36.8%,respectively.Among them,the 2D nanosheets g-C_(3)N_(4) prepared with dicyandiamide as a precursor treated at 580℃for 4 hours exhibited the best photocatalytic activity,and its degradation efficiency of methylene blue can reach 91.1%,which is 40%higher than that of the unexfoliated sample.After 4 cycles of use,the degradation rate can still be maintained at 90%,showing good stability and repeatability.

关 键 词：氮化碳 热剥离 不同前驱体 光催化性能 

分 类 号：TB34[一般工业技术—材料科学与工程]