B和P共掺杂石墨相氮化碳的制备及其光催化性能研究

Preparation of B,P co-doped graphite phase carbon nitride and its photocatalytic properties

以尿素和二氰胺为前驱体,B_(2)O_(3)为B源,(NH_(4))_(2)HPO_(4)为P源,采用热缩聚法合成了B和P共掺杂石墨相氮化碳(g-C_(3)N_(4)),考察了硼磷掺杂对g-C_(3)N_(4)结构和光催化性能的影响。利用X射线衍射(XRD)、扫描电镜(SEM)、BET比表面积、X射线光电子能谱(XPS)、紫外-可见光(UV-Vis)等手段对样品进行了表征和分析,考察了其可见光下光催化降解亚甲基蓝染料的性能。结果表明:当B_(2)O_(3)掺入量为0.15g,(NH_(4))_(2)HPO_(4)掺入量为1%时,CNBP1%的光催化性能最优。这主要归因于B、P元素的电负性差异有助于强化氮化碳中内建电场强度进而促进光生电子和空穴的有效分离。相比纯CN,CNBP1%表现出松散的片状多孔结构,更窄的禁带宽度和更强的可见光吸收能力。

In this study,B,P co-doped graphitic phase carbon nitride(g-C_(3)N_(4))was synthesized by thermal condensation using urea and dicyandiamide as precursors,B_(2)O_(3)as B source and(NH_(4))_(2)HPO_(4)as P source,and the effects of boron and phosphorus doping on the structure and photocatalytic properties of g-C_(3)N_(4)were investigated.The samples were characterized and analyzed by XRD,SEM,BET,XPS,and UV-Vis to investigate their performance of photocatalytic degradation of methylene blue dye under visible light.The results showed that the photocatalytic performance of the sample CNBP1%was optimal when the doping amount of B_(2)O_(3)was 0.15g and the doping amount of(NH_(4))_(2)HPO_(4)was 1%.This was mainly attributed to the electronegativity difference of B and P elements,which helped to intensify the strength of the built-in electric field in carbon nitride,thereby promoting the effective separation of photogenerated electrons and holes.Compared with pure CN,CNBP1%exhibited a loose lamellar porous structure,a narrower forbidden bandwidth,and stronger visible light absorption.