Activated carbons as green and effective catalysts for generation of reactive radicals in degradation of aqueous phenol

Abstract

Several activated carbons (ACs) were used as metal-free catalysts for degradation of a toxic organic compound, phenol, in the presence of different oxidants, H 2 O 2 , peroxydisulfate (PS) and peroxymonosulfate (PMS). It was found that ACs were effective in heterogeneous activation of PMS to produce sulfate radicals for degradation of phenol, much better than H 2 O 2 and PS. Particle size of AC significantly influenced AC activity, and powder AC was much more effective than granular AC. The complete phenol removal could be achieved in 15 min on powder activated carbon (PAC) under the conditions of [phenol] ¼ 25 mg L À1 , [PAC] ¼ 0.2 g L À1 , [PMS] ¼ 6.5 mmol L À1 , and T ¼ 25 C. It was also found that phenol degradation was significantly influenced by PMS loading, catalyst loading, phenol concentration and temperature. Surface activation of PMS and phenol adsorption played important roles in phenol degradation. Surface coverage by intermediate adsorption and structural change induced deactivation of AC and catalytic activity could be partially recovered by regeneration using calcination. † Electronic supplementary information (ESI) available: XRD, TGA of powder activated carbon, effect of phenol concentration and effect of catalyst loading and rate constant. See

Catalytic degradation of bisphenol A by CoMnAl mixed metal oxides catalyzed peroxymonosulfate: Performance and mechanism

“…8d) two strong peaks can be observed in the spectrum of used MMO both at acid and neutral pH. One is at 1040 cm À1 , which is corresponding to S-O stretching vibration [47,48], and the other one is assigned to aromatic ring C@C stretching vibration at 1500 cm À1 . In addition, several relatively weak bands at 2940, 1385, 1200 and 833 cm À1 are observed, which are due to C-H stretching vibration, C-O stretching vibration and C-H out-plane bending vibration, respectively.…”

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

“…Complete phenol removal was achieved in 40 min on 3D hexagonally-ordered mesoporous carbon (CMK-3), while the reaction time for complete phenol decomposition was 210 min on cubically ordered mesoporous carbon (CMK-8). It has been reported that an activated carbon shows a similar activity [53].…”

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].…”