Facile synthesis of nitrogen doped reduced graphene oxide as a superior metal-free catalyst for oxidation

Abstract

Nitrogen (5.61 at%) doped reduced graphene oxide synthesized via a facile method was demonstrated as a superior metal-free catalyst for activation of peroxymonosulfate. Codoping with boron would further enhance the catalytic activity and the stability, providing a promising green material for environmental remediation.

Nanocarbons in different structural dimensions (0–3D) for phenol adsorption and metal-free catalytic oxidation

“…GNP had a lower SSA than SWCNTs, while it showed a much better adsorption at around 40% phenol removal in 180 min. The phenol adsorption of GNP was much higher than reported rGO samples [11,22]. The bonds and flat structure of graphene might significantly contribute to the better adsorptive performance of GNP [13].…”

“…As GNP showed around 40% phenol removal in adsorption tests, the catalysis on GNP was not effective. The catalysis on GNP was not as good as rGO [4,11,20,22], which might be due to the different functional groups and defective structures. For the first time, this study observed the effective catalytic activation of PMS on CMK-3 and CMK-8.…”

“…XPS suggested that C O groups was increased from 0.35 at.% to 1.18 at.%. In previous studies [11,20,22], the C O was proposed to be one of the active sites for PMS activation. Yet such a case was not applied to C 60 , due to the much high oxygen species, which is similar to GO [11].…”

“…Physical CO 2 activation at a high temperature and chemical activation using ZnCl 2 were applied to improve the porous structure and surface features of rGO samples, and enhanced adsorption and catalysis were then achieved [4,20]. It was suggested that three important parameters such as specific surface area (SSA), porous structure and specific functional groups can enhance the performance of the green catalysts [4,13,[20][21][22].…”

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].…”