Looking at the overlooked hole oxidation: Photocatalytic transformation of organic contaminants on graphitic carbon nitride under visible light irradiation
Looking at the overlooked hole oxidation: Photocatalytic transformation of organic contaminants on graphitic carbon nitride under visible light irradiation
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审视被忽视的空穴氧化：可见光照射下石墨氮化碳上有机污染物的光催化转化
DOI：
10.1016/j.apcatb.2018.09.012
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Shuai, Danmeng
中科院分区：
文献类型：
--
作者：
Zheng, Qinmin;Xu, Enshi;Park, Eun;Chen, Hanning;Shuai, Danmeng
太阳能光催化是一种可持续的过程，通过攻击光生成的活性物质（如空穴、活性氧物质，如自由基dotOH、O2 -自由基dot/ ho2自由基dot、H2O2和1o2）来破坏持久性环境污染物。石墨氮化碳（g-C3N4）是一种很有前途的聚合物光催化剂，其高度可调的性质使其具有增强的光催化活性，可用于环境修复。在这项研究中，我们利用模拟和实验工具，系统地评估了未掺杂和碳(C)掺杂的g- c3n4样品的反应物质的产生，并确定了这些物质在模拟可见光照射（氙灯，λ > 400 nm）下对污染物氧化的作用。两种g- c3n4样品都产生了可以忽略不计的dotOH或三重激发态（3g-C3N4*），但与未掺杂的g- c3n4样品相比，掺杂c的g- c3n4样品产生了更多的1o2、O2−自由基点和h2o2。令人惊讶的是，所有这些氧化物种对污染物苯酚和阿特拉津的降解动力学没有实质性贡献，至少对母体化合物的初始氧化没有实质性贡献；此外，研究结果还突出了孔洞在污染物转化中的重要作用。通过分子动力学（MD）和密度泛函数理论（DFT）模拟研究了污染物表面介导的空穴氧化，包括污染物在光催化剂表面的吸附（用结合自由能量化）和污染物到受激发光催化剂的电子转移动力学（用协调质子耦合电子转移（CPCET）速率量化）。模拟结果表明，c掺杂有利于阿特拉津与g-C3N4的结合，而不利于苯酚的结合。c掺杂也显著降低了苯酚对g- c3n4的CPCET率，但对阿特拉津的CPCET率几乎没有影响。这些模拟和实验结果可以解释我们之前的研究中苯酚和阿特拉津在未掺杂和掺杂c的g- c3n4上的选择性氧化，也突出了之前很大程度上被忽视的孔在污染物转化中的主导作用。这项研究产生了光催化氧化的机理见解，并将为g- c3n4作为一种有效的可见光响应光催化剂的合理设计提供指导，包括污染物降解，化学合成等许多应用。
Solar-energy-enabled photocatalysis is a sustainable process to destruct persistent environmental pollutants via the attack of photogenerated reactive species (e.g., holes, reactive oxygen species such asradical dotOH, O2−radical dot/HO2radical dot, H2O2, and1O2). Graphitic carbon nitride (g-C3N4) has emerged as a promising polymeric photocatalyst, and its highly tunable properties allow the material with an enhanced photocatalytic activity for environmental remediation. In this study, by taking advantage of simulation and experimental tools, we systematically evaluated the production of reactive species of undoped and carbon (C)-doped g-C3N4samples, and identify the role of these species in contaminant oxidation under simulated visible sunlight irradiation (xenon lamp, λ > 400 nm). Both g-C3N4samples produced negligibleradical dotOH or triplet-excited states (3g-C3N4*), but the C-doped g-C3N4sample generated more1O2, O2−radical dot, and H2O2compared to the undoped counterpart. Surprisingly, all these oxidative species did not contribute substantially for the degradation kinetics of contaminant phenol and atrazine, at least for the initial oxidation of the parent compounds; and the results otherwise highlighted the important role of the holes for contaminant transformation. The surface-mediated hole oxidation of the contaminants, including the adsorption of the contaminants on the photocatalyst surface (quantified by the binding free energy) and electron transfer kinetics from the contaminants to the excited photocatalysts (quantified by the concerted proton-coupled electron transfer (CPCET) rate) were investigated by molecular dynamics (MD) and density functional theory (DFT) simulations. The simulation results indicated that C-doping could favor the binding of atrazine but not of phenol on g-C3N4. The C-doping also significantly decreased the CPCET rate of phenol on g-C3N4but could have little to no adverse impact for the CPCET rate of atrazine. These simulation and experimental results could explain the selective oxidation of phenol and atrazine on undoped and C-doped g-C3N4in our previous study, and the results also highlight the dominant role of the holes for contaminant transformation that was largely overlooked before. This study generates mechanistic insights of photocatalytic oxidation, and will provide guidelines for the rational design of g-C3N4as an effective visible-light-responsive photocatalyst for many applications, including contaminant degradation, chemical synthesis, and beyond.
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DOI：
--
发表时间：
2016
期刊：
影响因子：
--
作者：
M. Antoniou;Cen Zhao;K. O’Shea;Geshan Zhang;D. Dionysiou;Chun Zhao;Changseok Han;M. Nadagouda;Hyeok Choi;T. Fotiou;T. Triantis;A. Hiskia
通讯作者：
A. Hiskia
功能模式热电子转移理论
DOI：
--
发表时间：
2016
期刊：
影响因子：
--
作者：
J. Elenewski;J. Cai;Wei Jiang;Hanning Chen
通讯作者：
Hanning Chen
一种无金属聚合物光催化剂，用于可见光下从水中制氢
影响因子：
41.2
作者：
Wang, Xinchen;Maeda, Kazuhiko;Antonietti, Markus
通讯作者：
Antonietti, Markus
新兴研究者系列：石墨氮化碳作为可见光响应光催化剂用于可持续水净化的进展和挑战
DOI：
10.1039/c7ew00159b
发表时间：
2017
期刊：
Environ. Sci.: Water Res. Technol.
影响因子：
--
作者：
Zheng, Qinmin;Shen, Hongchen;Shuai, Danmeng
通讯作者：
Shuai, Danmeng
影响因子：
4.4
作者：
NOSE, S
通讯作者：
NOSE, S