摘要
As one of the most promising metal-free photocatalysts for renewable H_(2) evolution,graphitic carbon nitride(g-C_(3)N_(4))has attracted notable attention.Regulating its morphology and electronic structure is crucial for enhancing its performance.In this work,aromatic small molecules and melamine were hydrothermally cotreated to form a novel supramolecular precur-sor,which was subsequently calcined to obtain aπ-πconjugated structure of g-C_(3)N_(4) photocatalyst.The introduction of benzene-ring structures expanded the conjugated system and promoted the excitation ofπelectrons,thereby broadening the light-absorption range of g-C_(3)N_(4).The synergism of bromine and chlorine provided abundant active sites for g-C_(3)N_(4),greatly promoted the migration of photogenerated charge carriers,and reduced the recombination probability,thus improving in photocatalytic performance.Therefore,the g-C_(3)N_(4) photocatalyst obtained from 2-bromo-5-chlorobenzoic acid-derived supramolecular precursor exhibited a visible-light(λ≥400 nm)photocatalytic H_(2) evolution activity of 839.8μmol/(h g),which was about three times that of the unmodifi ed g-C_(3)N_(4).This work off ers a novel perspective for g-C_(3)N_(4) application in the fi eld of photocatalysis and expands the utilization of aromatic small molecules in photocatalysts modifi cation.
基金
supported by the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.52488201)
the National Natural Science Foundation of China(Nos.52276213,52206276 and 52376209)
the Key Research and Development Program of Shaanxi Province(No.2024GX-YBXM-459)
the Fundamental Research Funds for the Central Universities.
