Electron, hole and radical competition mechanism of layered porous g-C3N4 for hydrogen generation and organic pollutant degradation
Electron, hole and radical competition mechanism of layered porous g-C3N4 for hydrogen generation and organic pollutant degradation
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DOI：
10.1016/j.jcat.2024.115332
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发表时间：
2024-02
影响因子：
7.3
通讯作者：
Mingyuan Guo;Yong-huan Ma;Zhanqing Liu;Donghua Wang;Yuhao Yang;Xiaolong Li;Enzhou Liu
中科院分区：
文献类型：
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作者：
Mingyuan Guo;Yong-huan Ma;Zhanqing Liu;Donghua Wang;Yuhao Yang;Xiaolong Li;Enzhou Liu
卤素掺杂是调控g-C3 N4电子结构、提高其光催化性能的有效途径。本文采用盐辅助的方法制备了层状多孔卤素掺杂的g-C3 N4。讨论了卤素电负性和孔形态的影响。高电负性的F掺杂g-C3 N4具有更小的孔径和更高的比表面积，对反应物的吸附性能增强。随着电负性的增加，层状多孔g-C3 N4的H2产率降低，RhB降解率显著增加，这与传统的卤代酸掺杂g-C3 N4和单层g-C3 N4制备的卤素掺杂g-C3 N4有显著不同。H2析出量的减少主要是由于H2对卤素离子的强吸附作用，卤素离子与H+之间的强相互作用难以解离。此外，随着电负性的增加，卤素掺杂g-C3 N4的RhB降解性能显著提高。F掺杂g-C3 N4降解RhB的主要活性物种为空穴（h+），与纯g-C3 N4和Cl/Br掺杂g-C3 N4的空穴（·O2-）完全不同.这一工作有助于我们更好地理解电负性和孔形态对层状多孔g-C3 N4的H2生成和RhB降解性能的作用和重要性。
Halogen doping is an effective approach to regulate the electronic structure and improve photocatalytic properties of g-C3N4. Here, a salt-assisted approach was employed to prepare layered porous halogen-doped g-C3N4. The effects of halogen electronegativity and pore morphology were discussed. Highly electronegative F-doped g-C3N4with smaller pore size and higher surface area displayed the enhanced absorption property on reactants. The H2production rate decreased and the RhB degradation significantly increased with increasing the electronegativity of layered porous g-C3N4, which was significantly different from the conventional halogen-doped g-C3N4prepared with halogenated acid and monolayer g-C3N4. The decreased H2evolution can be ascribed to the strong adsorption property, and the strong interactions between halide ions and H+were difficult to be disassociated. Additionally, the RhB degradation performance of halogen-doped g-C3N4significantly increased with increasing the electronegativity. The most active species that dominated the RhB degradation of F-doped g-C3N4are leaved holes (h+), which are totally different from that of the pristine g-C3N4and Cl/Br-doped g-C3N4(superoxide radicals,·O2–). This work helps us to well understand the role and importance of electronegativity and pore morphology on the H2generation and RhB degradation properties of layered porous g-C3N4.