| Abstract: | The rational construction of a high-efficiency step-scheme heterojunctions is an effective strategy to accelerate the pho-tocatalytic H2.Unfortunately,the variant energy-level matching be-tween two different semiconductor confers limited the photocatalytic performance.Herein,a newfangled graphitic-carbon nitride (g-C3N4)based isotype step-scheme heterojunction,which consists of sul-fur-doped and defective active sites in one microstructural unit,is successfully developed by in-situ polymerizing N,N-dimethyl-formamide (DMF) and urea,accompanied by sulfur (S) powder.Therein,the polymerization between the amino groups of DMF and the amide group of urea endows the formation of rich defects.The propul-sive integration of S-dopants contributes to the excellent fluffiness and dispersibility of lamellar g-C3N4.Moreover,the developed heterojunc-tion exhibits a significantly enlarged surface area,thus leading to the more exposed catalytically active sites.Most importantly,the simultane-ous introduction of S-doping and defects in the units of g-C3N4 also results in a significant improvement in the separation,transfer and recom-bination efficiency of photo-excited electron-hole pairs.Therefore,the resulting isotype step-scheme heterojunction possesses a superior photocatalytic H2 evolution activity in comparison with pristine g-C3N4.The newly afforded metal-free isotype step-scheme heterojunction in this work will supply a new insight into coupling strategies of heteroatoms doping and defect engineering for various photocatalytic systems. |
