Selective Electrocatalytic Reduction of Oxygen to Hydroxyl Radicals via 3‐Electron Pathway with FeCo Alloy Encapsulated Carbon Aerogel for Fast and Complete Removing Pollutants. (22nd March 2021)

• Record Type: Journal Article
• Authors: Xiao, Fan; Wang, Zining; Fan, Jiaqi; Majima, Tetsuro; Zhao, Hongying; Zhao, Guohua
• Is Part Of: Angewandte Chemie. Volume 133:Number 18(2021)
• Page Start: 10463
• Page End: 10471
• Publication Date: 2021-03-22
• Subjects: carbon aerogel -- FeCo alloy -- hydroxyl radical -- oxygen reduction reaction -- water purification; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202101804
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: We reported the selective electrochemical reduction of oxygen (O2 ) to hydroxyl radicals ( . OH) via 3‐electron pathway with FeCo alloy encapsulated by carbon aerogel (FeCoC). The graphite shell with exposed ‐COOH is conducive to the 2‐electron reduction pathway for H2 O2 generation stepped by 1‐electron reduction towards to . OH. The electrocatalytic activity can be regulated by tuning the local electronic environment of carbon shell with the electrons coming from the inner FeCo alloy. The new strategy of . OH generation from electrocatalytic reduction O2 overcomes the rate‐limiting step over electron transfer initiated by reduction‐/oxidation‐state cycle in Fenton process. Fast and complete removal of ciprofloxacin was achieved within 5 min in this proposed system, the apparent rate constant ( k obs ) was up to 1.44±0.04 min −1, which is comparable with the state‐of‐the‐art advanced oxidation processes. The degradation rate almost remains the same after 50 successive runs, suggesting the satisfactory stability for practical applications. Abstract : Hydroxyl radicals are efficiently and continuously generated from selective electrochemical O2 reduction via 3‐electron pathway with FeCoC electrode, overcoming the rate‐limiting step of electron transfer initiated by reduction‐/oxidation‐state cycle. Fast and complete removal of organics with the apparent rate constant of 1.44±0.04 min −1 represents high potential for practical water purification.