Deciphering co-catalytic mechanisms of potassium doped g-C3N4 in Fenton process.
Deciphering co-catalytic mechanisms of potassium doped g-C3N4 in Fenton process.
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DOI：
10.1016/j.jhazmat.2020.122472
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发表时间：
2020-03
影响因子：
13.6
通讯作者：
Wei Yan;Ru Zhang;Feng Ji;C. Jing
中科院分区：
文献类型：
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作者：
Wei Yan;Ru Zhang;Feng Ji;C. Jing
传统的芬顿反应由于Fe（III）/Fe（II）循环效率低，H2 O2分解不完全，限制了其去除污染物的能力。本研究对g-C3 N4共催化芬顿氧化过程以及钾离子掺杂在其中的作用机制进行了系统的研究。在g-CN-3. 9% K/Fe（III）/H2 O2体系中，恩诺沙星（ENR）的降解率是传统芬顿反应的204倍。这种显著的增强归因于Fe（III）和K掺杂的g-C3 N4之间容易形成的络合物。K掺杂促进了光激发的e−从g-CN-3.9%K表面转移到Fe（III），导致加速Fe（III）还原为Fe（II）。此外，该配合物被H2 O2配位并氧化，导致形成Fe（V），从而快速降解ENR。而在无K掺杂的情况下，g-CN/Fe（III）/H_2O_2体系中，由于Fe（III）没有络合，只有自由基dotO_2对ENR的降解起主导作用。该研究为调控g-C3 N4/芬顿偶联催化体系中K掺杂光激发e-的传递方向提供了新的视角。
Conventional Fenton reaction for the pollutant removal is restricted by incomplete H2O2decomposition due to the low efficient Fe(III)/Fe(II) cycle. In this study, the co-catalytic Fenton processes with g-C3N4and the roles of potassium doping in the diverse mechanisms were comprehensively investigated. The degradation rate of enrofloxacin (ENR) in g-CN-3.9 %K/Fe(III)/H2O2was 204 times higher than that in conventional Fenton reaction. This significant enhancement was ascribed to the readily formed complex between Fe(III) and K doped g-C3N4.The K doping facilitated the transfer of photoexcited e−from g-CN-3.9 %K surface to Fe(III), leading to an accelerated Fe(III) reduction to Fe(II). In addition, this complex was coordinated and oxidized by H2O2, resulting in the formation of Fe(V) which quickly degraded ENR. Without K doping, on the other hand, onlyradical dotO2dominated the degradation of ENR in g-CN/Fe(III)/H2O2due to the lack of Fe(III) complexation. This study provides a new perspective for regulating the transfer directions of the photoexcited e−with K doping in g-C3N4/Fenton coupled catalytic system for water purification.