No abstract

No abstract

No abstract

No abstract

Activation of reduced graphene oxide (RGO) using CO 2 to obtain highly porous and metal-free carbonaceous materials for adsorption and catalysis was investigated. The facile one-pot thermal process can simultaneously reduce graphene oxide and produce activated RGO without introducing any solid or aqueous activation agent. This process can significantly increase the specific surface area (SSA) of RGO from 200 to higher than 1200 m 2 /g, and the obtained materials were proven to be highly effective for adsorptive removal of both anionic (phenol) and cationic (methylene blue, MB) organics from water. Moreover, the activated RGO materials exhibited much better activity in effective activation of peroxymonosulfate (PMS) to produce sulfate radicals for oxidative degradation of MB.

No abstract

This paper reports the synthesis of magnetic CoFe 2 O 4 −reduced graphene oxide (rGO) hybrids and the catalytic performance in heterogeneous activation of peroxymonosulfate (PMS) for decomposition of phenol. The surface morphologies and structures of the CoFe 2 O 4 −rGO hybrids were investigated by field emission scanning electron microscopy (SEM), energydispersive X-ray spectrometer (EDS), transmission electron microscopies(TEM), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption−desorption isotherm, and thermogravimetric analysis (TGA). Through an in situ chemical deposition and reduction, CoFe 2 O 4 −rGO hybrids with CoFe 2 O 4 nanoparticles of 23.8 nm were produced. Catalytic testing showed CoFe 2 O 4 −rGO hybrids exhibited much better catalytic activity than CoFe 2 O 4 , which suggests rGO plays an important role in CoFe 2 O 4 −rGO hybrids for the decomposition of phenol. Moreover, the hybrid catalyst presents good magnetism and could be separated from solution by a magnet.

This paper reports the synthesis of Co 3 O 4 −reduced graphene oxide (rGO) hybrids and the catalytic performance in heterogeneous activation of peroxymonosulfate (PMS) for the decomposition of phenol. The surface morphologies and structures of the Co 3 O 4 −rGO hybrids were investigated by field emission scanning electron microscopy (SEM), energydispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Through an in situ chemical deposition and reduction, Co 3 O 4 −rGO hybrids with Co 3 O 4 nanoparticles at an average size of 33 nm were produced. Catalytic testing showed that 20 mg/L of phenol could be completely oxidized in 20 min at 25 °C on Co 3 O 4 −rGO hybrids, which is mostly attributed to the generation of sulfate radicals through Co 3 O 4 -mediated activation of PMS. Phenol oxidation was fitted by a pseudo-zero-order kinetic model. The rate constant was found to increase with increasing temperature and PMS dosage, but to decrease with increasing initial phenol concentration. The combination of Co 3 O 4 nanoparticles with graphene sheets leads to much higher catalytic activity than pure Co 3 O 4 . rGO plays an important role in Co 3 O 4 dispersion and decomposition of phenol.