二维Ta2C助催化剂用于增强光催化H2O2合成及有机污染物降解OA

Hydrogen peroxide(H2O2)serves as an environmentally benign oxidant,and its photocatalytic synthesis coupled with environmental remediation is an extremely attractive strategy.To address sluggish charge dynamics and surface reaction in conventional photocatalysts,two-dimensional tantalum carbide(Ta2C)MXene was explored as an effective cocatalyst to engineer the interfacial electronic structure of graphitic carbon nitride(g-C3N4),enabling highly efficient H2O2 production and simultaneous tetracycline hydrochloride(TCH)degradation.Systematic characterization and theoretical calculations revealed that the significant work function difference between the two components induces Fermi level equilibration and facilitates built-in electric field formation,which drives directional photogenerated electron migration from g-C3N4 to Ta2C,accelerating charge separation and suppressing charge recombination.The optimized g-C3N4/Ta2C-6(CT-6)composite achieved an H2O2 production rate of 4584.7 μmol g-1 h-1,together with 86.56%of TCH degradation within 1 h,markedly outperforming pristine g-C3N4.Mechanistic studies show that H2O2 is mainly produced through a two-step one-electron oxygen reduction pathway,and the reactive oxygen species generated in the reaction play a key role in TCH degradation.This study demonstrates the potential of Ta2C as a non-noble-metal cocatalyst and establishes a clear correlation between interfacial electronic structure,charge transfer dynamics and photocatalytic reaction pathways in MXene-based heterojunctions,offering atomic-level insights and theoretical basis for the design of high-performance,multifunctional photocatalysts.