Facet-dependent activation of oxalic acid over hematite nanocrystals under the irradiation of visible light for efficient degradation of pollutants  

作　　者：Zhixiong Yang Yuan Li Xiaotian Wang Jiaming Li Jiquan Wang Gaoke Zhang 

机构地区：[1]Hubei Key Laboratory of Mineral Resources Processing and Environment,State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China [2]Hubei Engineering Consulting Co.,Ltd.,Wuhan 430071,China

出　　处：《Journal of Environmental Sciences》2024年第8期204-214,共11页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.22176151)。

摘　　要：Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity.However,its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it constitutes.Thus,we constructed a photochemical system composed of hematite with{001}facet of high activity facet and low-cost and non-toxic oxalic acid(OA)for the removal of various types of pollutants.The removal rate for the degradation of metronidazole,tetracycline hydrochloride,Rhodamine B,and hexavalent chromium by hematite nanoplate with the exposed{001}facet activating OA under visible light irradiation was 4.75,2.25,2.33,and 2.74 times than that by the exposed{110}facet,respectively.Density functional theory(DFT)calculation proved that the OA molecule was more easily adsorbed on the{001}facet of hematite than that on the{110}facet,which would favor the formation of the more Fe(Ⅲ)-OA complex and reactive species.In addition,the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals,and the possible degradation pathway for metronidazole included carbon chain fracture,hydroxyethyl-cleavage,denitrogenation,and hydroxylation.Thus,this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.

关 键 词：HEMATITE Facet exposure Oxalic acid activation Fenton-like system Pollutant removal 

分 类 号：P579[天文地球—矿物学] X505[天文地球—地质学]