TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals

TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals

The use of heterogeneous catalysts to improve the Electro-Fenton (EF) process has attracted significant attention. However, complex redox reactions and multiple mass transfer steps during the EF process result in limited current efficiency with only a low rate of generation of hydroxyl radicals (·OH...

Full description

Bibliographic Details
Main Authors: Fei Miao, Mingming Gao, Xin Yu, Pengwei Xiao, Mei Wang, Yunkun Wang, Shuguang Wang, Xinhua Wang
Format: Article
Language:English
Published: Elsevier 2020-04-01
Series:Electrochemistry Communications
Online Access:http://www.sciencedirect.com/science/article/pii/S1388248120300382
id doaj-acbf76fda60a427985660559dd6ed114
record_format Article
spelling doaj-acbf76fda60a427985660559dd6ed1142020-11-25T03:03:27ZengElsevierElectrochemistry Communications1388-24812020-04-01113TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicalsFei Miao0Mingming Gao1Xin Yu2Pengwei Xiao3Mei Wang4Yunkun Wang5Shuguang Wang6Xinhua Wang7Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266200, ChinaShandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266200, China; Corresponding authors.Institute for Advanced Interdisciplinary Research (IAIR), University of Jinan, Jinan 250022, ChinaShandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266200, ChinaKey Laboratory of Plant Cell Engineering, Ministry of Education, School of Life Science, Shandong University, Qingdao 266200, ChinaShandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266200, ChinaShandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266200, ChinaShandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266200, China; Corresponding authors.The use of heterogeneous catalysts to improve the Electro-Fenton (EF) process has attracted significant attention. However, complex redox reactions and multiple mass transfer steps during the EF process result in limited current efficiency with only a low rate of generation of hydroxyl radicals (·OH). Herein, we establish a three-electron oxygen reduction reaction (ORR) process coupling adsorbed H2O2 (H2O2ad) generation with an in situ EF-like reaction on TiO2 during cathodic electrolysis. Anatase TiO2 was composited with graphite, enabling the electrochemical reduction of Ti4+ to Ti3+. H2O2ad was formed during the ORR, electrocatalyzed by TiO2, then the H2O2ad was reduced in situ to ·OH without desorption. The generation and decomposition of Ti-OH during the electrochemical reduction were directly observed by in situ Raman spectroscopy. This result was further confirmed by density functional theory (DFT) calculations. Based on this three-electron ORR mechanism, the ·OH yield reached 2.69 μg cm−2 min−1 and the current efficiency approached 92.8% at a current density of −0.80 mA cm−2 within 2 h during ORR on the TiO2/graphite (TiO2/C) cathode. Keywords: TiO2, Oxygen reduction reaction, Electrocatalysis, Hydroxyl radicalshttp://www.sciencedirect.com/science/article/pii/S1388248120300382
collection DOAJ
language English
format Article
sources DOAJ
author Fei Miao
Mingming Gao
Xin Yu
Pengwei Xiao
Mei Wang
Yunkun Wang
Shuguang Wang
Xinhua Wang
spellingShingle Fei Miao
Mingming Gao
Xin Yu
Pengwei Xiao
Mei Wang
Yunkun Wang
Shuguang Wang
Xinhua Wang
TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals
Electrochemistry Communications
author_facet Fei Miao
Mingming Gao
Xin Yu
Pengwei Xiao
Mei Wang
Yunkun Wang
Shuguang Wang
Xinhua Wang
author_sort Fei Miao
title TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals
title_short TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals
title_full TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals
title_fullStr TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals
title_full_unstemmed TiO2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals
title_sort tio2 electrocatalysis via three-electron oxygen reduction for highly efficient generation of hydroxyl radicals
publisher Elsevier
series Electrochemistry Communications
issn 1388-2481
publishDate 2020-04-01
description The use of heterogeneous catalysts to improve the Electro-Fenton (EF) process has attracted significant attention. However, complex redox reactions and multiple mass transfer steps during the EF process result in limited current efficiency with only a low rate of generation of hydroxyl radicals (·OH). Herein, we establish a three-electron oxygen reduction reaction (ORR) process coupling adsorbed H2O2 (H2O2ad) generation with an in situ EF-like reaction on TiO2 during cathodic electrolysis. Anatase TiO2 was composited with graphite, enabling the electrochemical reduction of Ti4+ to Ti3+. H2O2ad was formed during the ORR, electrocatalyzed by TiO2, then the H2O2ad was reduced in situ to ·OH without desorption. The generation and decomposition of Ti-OH during the electrochemical reduction were directly observed by in situ Raman spectroscopy. This result was further confirmed by density functional theory (DFT) calculations. Based on this three-electron ORR mechanism, the ·OH yield reached 2.69 μg cm−2 min−1 and the current efficiency approached 92.8% at a current density of −0.80 mA cm−2 within 2 h during ORR on the TiO2/graphite (TiO2/C) cathode. Keywords: TiO2, Oxygen reduction reaction, Electrocatalysis, Hydroxyl radicals
url http://www.sciencedirect.com/science/article/pii/S1388248120300382
work_keys_str_mv AT feimiao tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
AT mingminggao tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
AT xinyu tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
AT pengweixiao tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
AT meiwang tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
AT yunkunwang tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
AT shuguangwang tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
AT xinhuawang tio2electrocatalysisviathreeelectronoxygenreductionforhighlyefficientgenerationofhydroxylradicals
_version_ 1724685663039651840

Similar Items