摘要
光催化剂在工业废水处理中发挥着重要作用.本工作以室温下一步合成的片状铁基金属有机凝胶(Fe-based Metal-organic gel,Fe-MOG)为前驱体,在不同温度下煅烧得到了片状(300-Fe_(2)O_(3)和400-Fe_(2)O_(3))和球形(500-Fe_(2)O_(3)和600-Fe_(2)O_(3))两种形貌的衍生三氧化二铁(Fe_(2)O_(3)).通过一系列测试手段对衍生Fe_(2)O_(3)的晶体结构和光电性能进行了表征.其中,具有碳骨架结构的400-Fe_(2)O_(3)因其优良的电子传输性能和较高的光生电荷分离效率表现出优异的光催化活性,可在中性条件下60 min内光降解97.5%的罗丹明B(Rh B),并且在连续五次循环实验后其降解效率仍能达到85.3%.本工作为开发和设计具有优异催化活性的半导体光催化剂提供了新的思路.
Photocatalysts play an important role in industrial wastewater treatment.So far,the photocatalysts of photoFenton degradation of water pollutants include metal-organic frameworks,two-dimensional layered hydroxides,and transition metal oxides.Among them,transition metal oxides have become a research hotspot because of their easy availability of metal ions,stability and non-toxicity during degradation.In particular,ferric oxide(Fe_(2)O_(3))has the advantages of wide visible light absorption range,good optical response and high thermodynamic stability,which is considered to be a promising semiconductor photocatalyst.Herein,in this work,Fe_(2)O_(3)of two morphologies,flakes(namely 300-Fe_(2)O_(3)and 400-Fe_(2)O_(3))and spheres(namely 500-Fe_(2)O_(3)and 600-Fe_(2)O_(3))were obtained by calcinating sheet-like iron-based metal-organic gel(Fe-MOG)synthesized with Fe^(3+)and 1,10-phenanthroline-2,9-dicarboxylic acid in one step at room temperature,and were used for photo-Fenton degradation of rhodamine B(Rh B).The crystal structure and optoelectronic properties of the as-prepared Fe_(2)O_(3)were characterized by powder X-ray diffraction(PXRD),X-ray photoelectron spectroscopy(XPS),energy-dispersive X-ray spectroscopy elemental mapping(EDS),the UV-Vis diffuse reflectance spectra(UV-Vis DRS)and electrochemical impedance spectroscopy(EIS).Among them,400-Fe_(2)O_(3)with carbon skeleton structure exhibited excellent electron transport performance and high photogenerated charge separation efficiency,endowing it with remarkable catalytic activity.In addition,the existence of oxygen vacancy in 400-Fe_(2)O_(3)promoted the formation of Fe^(2+),which was the key factor to enhance the photo-Fenton activity.400-Fe_(2)O_(3)could photocatalytically degrade 97.5%Rh B within 60 min under neutral conditions,and the degradation efficiency was retained 85.3%after five consecutive cycles.Under visible light irradiation,a part of the photogenic electron(e-)generated by 400-Fe_(2)O_(3)reacted with O_(2)to generate superoxide anion radical(·O_(2)-),the other part of ereduced Fe^(3+)to Fe^(2+)in situ.Subsequently,Fe^(2+)can catalyze the decomposition of H2O_(2)into hydroxyl radicals(·OH),and participated in the photodegradation of Rh B together with·O_(2)-.This work provides a new idea for the development and design of semiconductor photocatalysts with excellent catalytic activity.
作者
郭湾
胡聪意
甄淑君
黄承志
李原芳
Guo Wan;Hu Congyi;Zhen Shujun;Huang Chengzhi;Li Yuanfang(Key Laboratory of Luminescence Analysis and Molecular Sensing,Ministry of Education,College of Chemistry and Chemical Engineering,Southwest University,Chongqing 400715,China;Key Laboratory of Luminescence and Real-Time Analysis System,College of Pharmaceutical Sciences,Southwest University,Chongqing 400715,China)
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2022年第12期1583-1591,共9页
Acta Chimica Sinica
基金
国家自然科学基金(No.21874109)资助
