Smart photocatalytic removal of ammonia through molecular recognition of zinc ferrite/reduced graphene oxide hybrid catalyst under visible-light irradiation
Smart photocatalytic removal of ammonia through molecular recognition of zinc ferrite/reduced graphene oxide hybrid catalyst under visible-light irradiation
复制标题
可见光照射下通过铁酸锌/还原氧化石墨烯杂化催化剂的分子识别智能光催化去除氨
DOI：
10.1039/c7cy00797c
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发表时间：
2017-08-07
影响因子：
5
通讯作者：
Qian, Jun-Chao
中科院分区：
文献类型：
--
作者：
Liu, Shou-Qing;Zhu, Xiao-Lei;Qian, Jun-Chao
采用一点法制备了还原氧化石墨烯负载铁酸锌（ZnFe 2 O 4/rGO）和铁酸锌（ZnFe 2 O 4）催化剂。采用X射线衍射、透射电子显微镜、傅里叶变换红外光谱、拉曼光谱、紫外-可见漫反射光谱、表面光电压谱和X射线光电子能谱对催化剂进行了表征。结果表明，所合成的ZnFe 2 O 4/rGO和ZnFe 2 O 4粒子均为立方晶系尖晶石型ZnFe 2 O 4，空间群为Fd 3 m，平均粒径分别为7.4和7.0 nm。结果表明，ZnFe 2 O 4/rGO复合催化剂在可见光照射下具有比单一ZnFe 2 O 4组分更高的光催化活性。更重要的是，ZnFe 2 O 4/rGO催化剂能够识别有机污染物-氨混合溶液中的氨，并基于ZnFe 2 O 4上的Zn阳离子与溶液中氨的配位识别，选择性地降解氨和氮气。傅里叶变换红外光谱、拉曼光谱和X射线光电子能谱证实了氨在ZnFe 2 O 4颗粒上的选择性吸附。Zn 2 p3/2和Zn 2 p1/2结合能的移动证实了Zn阳离子与氨的配位作用。表面光电压谱显示，光生空穴移动到ZnFe 2 O 4粒子的表面后，入射可见光照射，并降解氨吸附在催化剂表面上。这些发现将鼓励更多基于协调识别的光催化研究。
Zinc ferrite loaded with reduced graphene oxide (ZnFe2O4/rGO) and zinc ferrite (ZnFe2O4) catalysts were synthesized via a one-spot method. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, surface photovoltage spectroscopy and X-ray photoelectron spectroscopy. Results revealed that the as-synthesized ZnFe2O4/rGO and ZnFe2O4 particles were cubic spinel-type ZnFe2O4 with space group number of Fd3m, and that their average diameters were 7.4 and 7.0 nm, respectively. The photocatalytic results indicated that the ZnFe2O4/rGO hybrid catalyst possesses higher activity than that of the single ZnFe2O4 component under visible-light irradiation. More importantly, the ZnFe2O4/rGO catalyst could recognize ammonia from an organic pollutant-ammonia mixed solution and selectively degrade ammonia and nitrogen gas based on the coordination recognition between Zn cations on ZnFe2O4 and ammonia in solution. Fourier-transform infrared, Raman and X-ray photoelectron spectra confirmed that ammonia was selectively adsorbed on ZnFe2O4 particles. The shifts of Zn 2p3/2 and Zn 2p1/2 binding energies confirmed the coordination between Zn cations and ammonia. The surface photovoltage spectra revealed that the photo-generated holes moved to the surface of ZnFe2O4 particles upon incident visible-light irradiation, and degraded ammonia adsorbed on the catalyst surface. These findings will encourage more investigations of photocatalysis based on coordination recognition.