微波法合成磷掺杂石墨相氮化碳催化剂及n-π^(*)电子跃迁对其光催化固氮性能的影响  

The Effect of n-π^(*) Electronic Transitions on the N_(2) Photofixation Ability of Phosphorus Doped g-C_(3)N_(4) Synthesized by Microwave Treatment

作　　者：关元昊 白金[1] 胡绍争 王菲 赵艳锋[1] GUAN Yuan-hao;BAI Jin;HU Shao-zheng;WANG Fei;ZHAO Yan-feng(School of Chemical Engineering,Liaoning Petrochemical University,Fushun 113001,China)

机构地区：[1]辽宁石油化工大学石油化工学院,辽宁抚顺113001

出　　处：《分子催化》2022年第2期180-189,共10页Journal of Molecular Catalysis(China)

基　　金：辽宁省自然基金项目(201602467);辽宁省教育厅一般项目(L2014145)资助

摘　　要：通过微波处理制备了具有优异光催化固氮性能的磷掺杂石墨相氮化碳(g-C_(3)N_(4))催化剂.采用XRD、N_(2)吸附、UV-Vis、SEM、XPS、ESR、PL等测试手段对制备的催化剂进行了表征.结果表明,P掺杂与微波处理工艺相结合能破坏g-C_(3)N_(4)中平面对称性的结构单元,激发了n-π^(*)电子跃迁过程.制备催化剂的吸收边界从465移动至600 nm处,明显促进了对可见光的吸收.P掺杂和微波处理的协同效应也提高了催化剂的比表面积和电子空穴对的分离效率.制备的催化剂的NH_(4)^(+)产率最高达到6.5 mg·L^(-1)·g_(cat)^(-1),是纯g-C_(3)N_(4)的13.5倍以上,且具有良好的光催化稳定性,为拓宽催化剂的光响应范围提供了新的途径.In this work,phosphorus doped g-C_(3)N_(4)with outstanding N_(2)photofixation ability was prepared via microwave treatment.XRD,N_(2)adsorption,UV-Vis,SEM,XPS,ESR and PL were used to characterize the asprepared catalysts.Combining the P doping with microwave treatment,the planar and symmetric heptazine units in g-C_(3)N_(4)was destroyed.This causes that the n-ππ^(*)electronic transition becomes allowed.The remarkable red shift of absorption edge from 465 to near 600 nm was observed,leading to the obviously promoted visible light absorption.The synergy effect of P doping and microwave treatment also enhances the surface area and separation efficiency of electron-hole pairs.The as-prepared catalyst displays the highest NH4+concentration of 6.5 mg·L^(-1)·g_(cat)^(-1),over 13.5 times higher than that of neat g-C_(3)N_(4),as well as the excellent photocatalytic stability.This work provides a new way to expand the photoresponse range of the catalyst.

关 键 词：石墨相氮化碳 n-π^(*)电子激发 微波处理 光催化固氮 磷掺杂 

分 类 号：TQ426[化学工程]