Reduced Graphene Oxide for Catalytic Oxidation of Aqueous Organic Pollutants

Abstract

We discovered that chemically reduced graphene oxide, with an I(D)/I(G) >1.4 (defective to graphite) can effectively activate peroxymonosulfate (PMS) to produce active sulfate radicals. The produced sulfate radicals (SO(4)(•-)) are powerful oxidizing species with a high oxidative potential (2.5-3.1 vs 2.7 V of hydroxyl radicals), and can effectively decompose various aqueous contaminants. Graphene demonstrated a higher activity than several carbon allotropes, such as activated carbon (AC), graphite powder (GP), graphene oxide (GO), and multiwall carbon nanotube (MWCNT). Kinetic study of graphene catalyzed activation of PMS was carried out. It was shown that graphene catalysis is superior to that on transition metal oxide (Co(3)O(4)) in degradation of phenol, 2,4-dichlorophenol (DCP) and a dye (methylene blue, MB) in water, therefore providing a novel strategy for environmental remediation.

Heterogeneous degradation of refractory pollutants by peroxymonosulfate activated by CoOx-doped ordered mesoporous carbon

“…It was worth noticing that the activation of persulfate by various carbonaceous materials, such as activated carbon [18], reduced graphene oxide (rGO) [19][20][21][22][23], carbon nanotubes (CNTs) [24][25][26][27][28], ordered mesoporous carbon (OMC) [29] and nanodiamond [30,31], had attracted much attention because of their environmental-friendly and high efficiency. Due to its high surface area, accessible mesopores and large pore volume, OMC had been applied in many areas such as adsorbents [32], catalysts and supports [33,34], and electrode materials [35].…”

Synthesis of Magnetic Carbon Supported Manganese Catalysts for Phenol Oxidation by Activation of Peroxymonosulfate

“…They found that α-Mn2O3 cubic possessed the best catalytic activity and for 25 ppm phenol, 100% decomposition achieved within 60 min when catalyst usage of 0.4 g/L. Liang et al [15] reported mesoporous MnO2 supported Co3O4 nanoparticles synthesized by impregnation and their performances in heterogeneous activation of peroxymonosulfate (PMS) for phenol degradation. They found that when Co3O4 loading rate is 3 wt %, MnO2 supported Co3O4 catalysts could achieve 100% phenol removal at phenol concentration of 25 ppm within 120 min.…”

“…Cobalt oxides are proven to be the effective heterogeneous catalysts for PMS activation [12,13]. Nevertheless, due to the metal leaching, employment of cobalt based catalysts would result in the secondary pollution caused by the toxicity of cobalt ions [14,15]. Moreover, improper recycling of these nanosized particles would also bring contaminant to the environment.…”

The Changes of Absorption and Catalytic Capacity on Reduced Graphene Oxide After Electron Beam Irradiation

“…It was reported that the reduction GO could be used as catalysts in some organic reactions, such as hydrogenation of nitrobenzene and oxidation of organic pollutants, [35][36][37][38] for the zigzag edge, defects and surface area of reduction GO could act as catalytic active sites to facilitate the activation of reactant molecules. 35,36,39 Actually, because of the di®erent -electron structure and extra electronic state, the sp 2 carbon atoms in the presence of open edges were di®erent from that of located in a hexagonal cell as a -conjugated system for a basal plane in perfect graphene, 40 which made graphene nanoribbon very active for bonding with heteroatomic groups such as H, OH, CH 3 and halogen.…”

“…35,36,39 Actually, because of the di®erent -electron structure and extra electronic state, the sp 2 carbon atoms in the presence of open edges were di®erent from that of located in a hexagonal cell as a -conjugated system for a basal plane in perfect graphene, 40 which made graphene nanoribbon very active for bonding with heteroatomic groups such as H, OH, CH 3 and halogen. 41 Therefore, the unique electronic structure of zigzag edges and defects on the R-GO/or R-RGO, to their high active catalyst for 4-NP.…”