Exceptional visible-light photoelectrocatalytic activity of In2O3/In2S3/CdS ternary stereoscopic porous heterostructure film for the degradation of persistent 4-fluoro-3-methylphenol
Exceptional visible-light photoelectrocatalytic activity of In2O3/In2S3/CdS ternary stereoscopic porous heterostructure film for the degradation of persistent 4-fluoro-3-methylphenol
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DOI：
10.1016/j.apcatb.2017.12.015
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
Yuting Xiao;Guohui Tian;Yajie Chen;Xin Zhang;H. Fu;H. Fu
中科院分区：
文献类型：
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作者：
Yuting Xiao;Guohui Tian;Yajie Chen;Xin Zhang;H. Fu;H. Fu
本工作采用连续原位离子交换反应成功制备了In 2 O3/In 2S 3/CdS三元立体多孔异质结构薄膜，利用光电催化降解难降解有机污染物4-氟-3-甲基苯酚。优化后的In 2 O3/In 2S 3/CdS三元立体多孔异质结构薄膜电极比In 2 O3和In 2 O3/In 2S 3薄膜具有更高的光电催化效率。所得的降解反应常数分别比In_2 O_3和In_2 O_3/In_2S_3二元薄膜高3倍和2倍。In_2O_3/In_2S_3/CdS复合膜电极具有极高的降解和矿化效率，这是由于其立体多孔异质结构中三元组分的协同作用。在三元异质结构中，具有纳米界面的双II型能带排列的存在可以显着改善电荷传输和电子空穴分离。这种立体多孔结构可以极大地提高可见光利用率和超亲水性，同时有利于物质传输和活性中心的可及性。采用离子色谱、气相色谱-质谱联用、总有机碳分析、活性物种捕集实验以及电子自旋共振技术研究了4-氟-3-甲基苯酚的降解和矿化过程。提出了一种统一的光电催化降解途径和机理，解释了降解和矿化过程。产生的超氧离子和空穴促进脱附过程，并有利于随后的苯环断裂和低分子量片段（如羧酸）的矿化。本研究为利用高效可见光光电催化降解持久性有机污染物，实现水体污染物的高效净化提供了一条途径。
In this work, In2O3/In2S3/CdS ternary stereoscopic porous heterostructure films were successfully fabricated via consecutive in situ ionic exchange reactions to degrade persistent 4-Fluoro-3-methylphenol through photoelectrocatalytic process. The optimized In2O3/In2S3/CdS ternary stereoscopic porous heterostructure film electrode showed much higher photoelectrocatalytic efficiency than the In2O3and In2O3/In2S3films. The resulting degradation reaction constant is about 3 and 2 times higher than that on In2O3and binary In2O3/In2S3films, respectively. The extraordinary higher degradation and mineralization efficiencies of the In2O3/In2S3/CdS composite film electrode come from the synergy of ternary components in the stereoscopic porous heterostructure. The existence of double type-II band alignment with nanosized interfaces in the ternary heterostructure can significantly improve charge transport and electron-hole separation. The stereoscopic porous architechture can greatly enhance visible light utilization and superhydrophilicity, and meanwhile facilitate the mass transport and accessibility of active sites. Ion chromatography, gas chromatography–mass spectrometry, total organic carbon analysis, active species trapping experiment as well as electron spin resonance techniques were employed to probe the degradation and the mineralization processes of 4-Fluoro-3-methylphenol. A unifying photoeletrocatalytic degradation route and mechanism is provided to explain the degradation and the mineralization processes. The generated more superoxide ions and holes promoted the defluorination process and favored the subsequent benzene ring cleavage and mineralization of low molecular weight fragments (e.g. carboxylic acids). This work provides a route to degrade persistent organic pollutants and realize efficient water contamination purification via efficient visible light photoelectrocatalytic process.