Nitrogen Vacancy Structure Driven Photoeletrocatalytic Degradation of 4-Chlorophenol Using Porous Graphitic Carbon Nitride Nanosheets
Nitrogen Vacancy Structure Driven Photoeletrocatalytic Degradation of 4-Chlorophenol Using Porous Graphitic Carbon Nitride Nanosheets
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DOI：
10.1021/acssuschemeng.8b00279
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发表时间：
2018-05-01
影响因子：
8.4
通讯作者：
Chen, Junhong
中科院分区：
文献类型：
--
作者：
Hou, Yang;Yang, Jian;Chen, Junhong
加入空位已被证明是改变光催化剂催化性能的重要途径。本文通过在H-2气氛下对本体石墨氮化碳（GCN）进行热处理，合成了一种具有可调氮空位的新型多孔石墨氮化碳纳米片。所得多孔纳米片厚度约为25纳米，横向尺寸为数百纳米，表面积高达114 m(2) g（-1）。系统表征结果表明，H-2处理引起了GCN的结构畸变，产生了氮空位。结果表明，制备的纳米片具有显著增强的光电催化性能。模拟阳光照射180 min后，有机碳总量仅剩19.5%，4-氯酚被完全消除。这种活性的增强主要是由于比表面积的增加、光吸收的改善以及光生成电荷载流子的有效分离和转移，这一点得到了光电化学测量结果的证实。自由基捕获研究表明，(OH)- o中心点自由基和空穴是降解4-氯酚的主要氧活性物质。我们的发现为设计和开发用于环境净化的高效光催化剂提供了新的见解。
Incorporating vacancies has been demonstrated as an important approach to alter the catalytic properties of photocatalysts. Herein, a novel porous graphitic carbon nitride (GCN) nanosheet with tunable nitrogen vacancies was synthesized through the thermal treatment of the bulk GCN under an H-2 atmosphere. The resulting porous nanosheets possessed similar to 25 nm in thickness, several hundred nanometers in lateral size, and a high surface area of 114 m(2) g(-1). The systematic characterization results revealed that the H-2 treatment induced the structure distortion of GCN with the creation of nitrogen vacancies. As a result, as prepared nanosheets exhibited considerably enhanced photoelectrocatalytic performances. After 180 min of simulated sunlight irradiation, only 19.5% of the total organic carbon still remained, while 4-chlorophenol was completely eliminated. This enhanced activity was mainly attributed to the increased specific surface area, improved light absorption, and the effective separation and transfer of photo generated charge carriers, which was confirmed by the photoelectrochemical measurement results. Radical trapping studies revealed that (OH)-O-center dot radicals and holes were involved as the major oxygen active species for the degradation of 4-chlorophenol. Our findings offer new insights into designing and developing highly efficient photocatalysts for environmental purification.