TY - JOUR

T1 - Single sheet iron oxide

T2 - An efficient heterogeneous electro-Fenton catalyst at neutral pH

AU - Huang, Li-Zhi

AU - Zhu, Mingtao

AU - Liu, Zizheng

AU - Wang, Zongping

AU - Hansen, Hans Christian B.

PY - 2019/2/15

Y1 - 2019/2/15

N2 - In order to overcome the inefficiency of heterogeneous electro-Fenton process for water treatment at neutral pH, single sheet iron oxide (SSI) derived from layered Fe(II)-Fe(III) double hydroxides (green rusts) was fabricated on an indium tin oxide electrode via layer by layer assembly and used in an undivided electrolysis cell. Use of radical scavengers demonstrated the formation of oxygen radicals by electrochemical reduction of oxygen at the SSI electrode, and the key role of hydroxyl radicals ([rad]OH) and superoxide anion (O2 –) radicals in degradation of the azo dye orange II. Analysis of degradation products by UV–vis, LC–MS and GC–MS further demonstrated that direct reduction toke place in addition to indirect oxidation. The reactivity of SSI as a heterogeneous electro-Fenton catalyst is two order of magnitude higher than its homogenous counterparts. The SSI electrode was highly stable as the dye degradation did not decrease after use for 19 h with no Fe leaching. The high dye removal efficiency was maintained in a wide pH range from 7 to 10 and in different supporting electrolytes, demonstrating the application of this process under various conditions mimicking natural waters.

AB - In order to overcome the inefficiency of heterogeneous electro-Fenton process for water treatment at neutral pH, single sheet iron oxide (SSI) derived from layered Fe(II)-Fe(III) double hydroxides (green rusts) was fabricated on an indium tin oxide electrode via layer by layer assembly and used in an undivided electrolysis cell. Use of radical scavengers demonstrated the formation of oxygen radicals by electrochemical reduction of oxygen at the SSI electrode, and the key role of hydroxyl radicals ([rad]OH) and superoxide anion (O2 –) radicals in degradation of the azo dye orange II. Analysis of degradation products by UV–vis, LC–MS and GC–MS further demonstrated that direct reduction toke place in addition to indirect oxidation. The reactivity of SSI as a heterogeneous electro-Fenton catalyst is two order of magnitude higher than its homogenous counterparts. The SSI electrode was highly stable as the dye degradation did not decrease after use for 19 h with no Fe leaching. The high dye removal efficiency was maintained in a wide pH range from 7 to 10 and in different supporting electrolytes, demonstrating the application of this process under various conditions mimicking natural waters.

KW - Advanced oxidation processes

KW - Electro-Fenton

KW - Green rust

KW - Heterogeneous electro catalyst

KW - Single sheet iron oxide

UR - http://www.scopus.com/inward/record.url?scp=85054787036&partnerID=8YFLogxK

U2 - 10.1016/j.jhazmat.2018.10.026

DO - 10.1016/j.jhazmat.2018.10.026

M3 - Journal article

C2 - 30336334

AN - SCOPUS:85054787036

VL - 364

SP - 39

EP - 47

JO - Journal of Hazardous Materials

JF - Journal of Hazardous Materials

SN - 0304-3894

ER -