Key role of activated carbon fibers in enhanced decomposition of pollutants using heterogeneous cobalt/peroxymonosulfate system

Abstract

BACKGROUND The development of effective and green peroxymonosulfate (PMS) activation processes has attracted considerable attention and still remains a great challenge in the environmental field. Herein, the cobalt catalyst was innovatively supported onto activated carbon fibers (ACFs) to construct an outstanding heterogeneous catalyst, Co@ACFs, for PMS activation. RESULTS Co@ACFs could effectively activate PMS to decompose dyes with about 100% removal rate in 35 min. Co@ACFs maintained its catalytic ability without detectable Co leaching during repeated batch experiments. More importantly, the catalyst presented an enhanced decomposition performance over most reported heterogeneous Co catalysts due to the significant role of ACFs: (i) high adsorption capacity in favor of the enhanced catalytic activity; (ii) ACFs as an electron donor to accelerate CoII/CoIII cycle thereby speeding up degradation. Combining electron paramagnetic resonance (EPR) with radical scavengers, it was found that both sulfate and hydroxyl radicals (SO4•‐, •OH) were responsible for the degradation of dyes. Unexpectedly, •OH was the dominant radical, different from the reported mechanism in typical Co/PMS. CONCLUSION This study not only paves the way to further develop highly efficient and green PMS activation processes, but also provides a new practical method for application to wastewater remediation. © 2015 Society of Chemical Industry

Activation of peroxymonosulfate with magnetic and recyclable Fe3 O4 @C/MnCo2 O4 nanocomposites for the decolorization of Acid Orange II

“…The concentrations of Mn, Co and Fe in the reaction mixture of the ‘Fe 3 O 4 @C/MnCo 2 O 4 + PSM’ system were determined by ICP as 0.07, 0.12 and 0.01 mg L −1 , respectively, which contributed to the metal leaching from Fe 3 O 4 @C/MnCo 2 O 4 . The levels of these ions in aqueous solution were comparable or lower than those leached from relevant oxides as reported in the literature . In order to investigate the possible contribution of the metal ions leached from the Fe 3 O 4 @C/MnCo 2 O 4 catalyst, the catalyst Fe 3 O 4 @C/MnCo 2 O 4 was separated when the reaction was finished and the remaining solution was used again to activate PMS for the removal of AO II.…”

“…Therefore, it is highly desirable to develop novel and recoverable heterogeneous catalysts to minimize heavy metal leaching while maintaining high performance PMS activation . For this purpose, investigations have been reported using cobalt oxides, manganese oxides, supported cobalt compounds, supported manganese compounds, and supported bimetallic catalysts such as Co‐Fe/SBA‐15 etc. as heterogeneous catalysts for the activation of PMS.…”

Magnetic carbon-supported cobalt prepared from one-step carbonization of hexacyanocobaltate as an efficient and recyclable catalyst for activating Oxone

“…Huang et al reported that using activated carbon fiber as a cobalt support could facilitate electron transfer to improve catalytic activity of cobalt[48].Shi et al …”

“…thereby accelerating the degradation kinetics[48]. Considering that Co 2+ ion is a benchmark catalyst to activate Oxone, Co 2+ ion of an equivalent amount to cobalt present in MCC was also tested and the corresponding degradation in shown inFig.…”

CoMoO4 as a novel heterogeneous catalyst of peroxymonosulfate activation for the degradation of organic dyes

“…[7][8][9] Recently, sulfate radicals (cSO 4 À ) have received intensive research interests as another powerful reactive radicals, because they can not only compensate some critical inadequacies of cOH, but also provide higher standard reduction potential (2.5-3.1 V) under neutral conditions than cOH (1.8-2.7 V). 10 It is well known that cSO 4 À can be released from peroxymonosulfate (PMS) or persulfate (PS) by heating, UV irradiation, ultrasonication, and catalytic activation, where catalytic activation has its own advantages without the assistance of necessary equipment and high-energy input.…”