Scholarlink

<p>Photocatalytic reduction of highly toxic Cr(VI) is fundamentally limited by inefficient charge separation and nonselective carrier recombination in conventional heterojunctions. Here we introduce a cascade CdS/C<sub>3</sub>N<sub>4</sub>/COF architecture in which charge recombination is deliberately engineered rather than suppressed. As inferred from bond structure analysis and PL spectroscopy, a triazine-based nanoporous COF is employed as an electronic mediator that facilitates preferential recombination of low-energy charge carriers, while preserving high-energy electrons in g-C<sub>3</sub>N<sub>4</sub> for reductive reactions. Structural and electrochemical analyses reveal strong interfacial coupling and Fermi-level equilibration across the ternary interfaces, giving rise to a COF-mediated S-scheme charge-transfer pathway. Under visible-light irradiation, the optimized heterostructure achieves rapid and efficient Cr(VI) removal (≈92% within 90&#xa0;min at pH 3), markedly exceeding the performance of binary analogues. Kinetic and scavenger studies confirm that the reaction is governed by direct electron transfer rather than adsorption or radical-driven pathways. This work establishes charge-preferential recombination as a powerful design principle for constructing high-performance photocatalysts and highlights the unique role of covalent organic frameworks as programmable electronic mediators in cascade heterostructures.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Rational design of a cascade CdS/C3N4/COF heterostructure for high-performance Cr(VI) photoreduction

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年2月11日

查看全文
  • H. Babaie,
  • Sh. Sohrabnezhad,
  • R. Foulady-Dehaghi

摘要

Photocatalytic reduction of highly toxic Cr(VI) is fundamentally limited by inefficient charge separation and nonselective carrier recombination in conventional heterojunctions. Here we introduce a cascade CdS/C3N4/COF architecture in which charge recombination is deliberately engineered rather than suppressed. As inferred from bond structure analysis and PL spectroscopy, a triazine-based nanoporous COF is employed as an electronic mediator that facilitates preferential recombination of low-energy charge carriers, while preserving high-energy electrons in g-C3N4 for reductive reactions. Structural and electrochemical analyses reveal strong interfacial coupling and Fermi-level equilibration across the ternary interfaces, giving rise to a COF-mediated S-scheme charge-transfer pathway. Under visible-light irradiation, the optimized heterostructure achieves rapid and efficient Cr(VI) removal (≈92% within 90 min at pH 3), markedly exceeding the performance of binary analogues. Kinetic and scavenger studies confirm that the reaction is governed by direct electron transfer rather than adsorption or radical-driven pathways. This work establishes charge-preferential recombination as a powerful design principle for constructing high-performance photocatalysts and highlights the unique role of covalent organic frameworks as programmable electronic mediators in cascade heterostructures.