Numerous approaches have been used to modify graphitic carbon nitride(g-C3N4)for improving its pho-tocatalytic activity.In this study,we demonstrated a facial post-calcination method for modified graphitic carbon nitride(g-C3N4-Ar/Air)to direct tuning band structure,i.e.,bandgap and positions of conduc-tion band(CB)/valence band(VB),through the control of atmospheric condition without involving any additional elements or metals or semiconductors.The synthesized g-C3N4-Ar/Air could efficiently de-grade sulfamethazine(SMT)under simulated solar light,i.e.,99.0％removal of SMT with rate constant k,=2.696 h-1 within 1.5 h(4.9 times than pristine g-C3N4).Material characterizations indicated that the damaged/partial-collapsed structure and decreased nanosheet-interlayer distance for g-C3N4-Ar/Air resulted in the shift of band structure due to the denser stacking of pristine g-C3N4 through oxidative exfoliation and planarization by air calcination.In addition,the bandgap of g-C3N4-Ar/Air was slightly shrunk from 2.82 eV(pristine g-C3N4)to 2.79 eV,and the CB was significantly upshifted from-0.44 eV(pristine g-C3N4)to-0.81 eV,suggesting the powerful ability for donating the electrons for O2 to form·O2-.Fukui index(f-)based on theoretical calculation indicated that the sites of SMT molecule with high values,i.e.,N9,C4 and C6,preferred to be attacked by·O2-and·OH,which is confirmed by the intermediates'analysis.The tuning method for graphitic carbon nitride provides a simple approach to regulate the charge carrier lifetime then facilitate the utilization efficiency of solar light,which exhibits great potential in efficient removal of emerging organic contaminants from wastewater.

Yue Liu;Long Chen;Xiaona Liu;Tianwei Qian;Meng Yao;Wen Liu;Haodong Ji

College of Environmental Science and Engineering,Taiyuan University of Technology,Jinzhong 030600,China;The Key Laboratory of Water and Sediment Science,Ministry of Education;College of Environment Science and Engineering,Peking University,Beijing 100871,China

中国化学快报（英文版）

[1]Yue Liu;Long Chen;Xiaona Liu;Tianwei Qian;Meng Yao;Wen Liu;Haodong Ji-.Tuning band structure of graphitic carbon nitride for efficient degradation of sulfamethazine:Atmospheric condition and theoretical calculation)[J].中国化学快报（英文版）,2022(03):1385-1389

Tuning,structure,graphitic,carbon,nitride,degradation,sulfamethazine,Atmospheric,condition,theoretical,calculation,Numerous,approaches,have,been,used,modify,C3N4,improving,pho,tocatalytic,activity,In,this,study,demonstrated,facial,post,calcination,method,modified,Ar,Air,direct,tuning,bandgap,positions,CB,valence,VB,through,control,atmospheric,without,involving,any,additional,elements,metals,semiconductors,synthesized,could,efficiently,grade,SMT,under,simulated,solar,removal,constant,within,times,than,pristine,Material,characterizations,indicated,that,damaged,partial,collapsed,decreased,nanosheet,interlayer,distance,resulted,due,denser,stacking,oxidative,exfoliation,planarization,by,air,slightly,shrunk,from,eV,significantly,upshifted,suggesting,powerful,ability,donating,electrons,O2,form,Fukui,sites,molecule,high,values,N9,C4,C6,preferred,attacked,which,confirmed,intermediates,analysis,provides,simple,regulate,charge,carrier,lifetime,then,facilitate,utilization,efficiency,exhibits,great,potential,emerging,organic,contaminants,wastewater

0.568471