Porous graphitic materials obtained from carbonization of organic xerogels doped with transition metal salts

Abstract

Porous carbons with a well developed graphitic phase were obtained via the pyrolysis of FeCl 3-, NiCl 2-, and CoCl 2-doped organic xerogels. Doping was realized through salt solubilization in a water/methanol solution of resorcinol and furfural. Carbon xerogels with tailored particles, porous morphology and various degrees of graphitization were obtained depending of the water/methanol ratio and the salt content and type in the starting solution of substrates. When obtained via pyrolysis, carbon xerogels retain the overall open-celled structure exhibiting depleted microporosity and a well-developed mesoporic region that expands into macropores. The removal of metal leads to carbon xerogels with specific surface areas between 170 and 585 m 2 /g and pore volume up to 0•76 cm 3 /g. The possibility of enhancing the porosity of xerogels via templating with colloidal silica was also investigated. It was assumed that from the three investigated salts, FeCl 3 makes the best choice for graphitization catalyst precursor to obtain uniformly graphitized mesoporous carbon xerogels. The obtained carbon samples were characterized by means of SEM, TEM, X-ray diffraction, Raman spectroscopy, N 2 physisorption and thermogravimetric analysis.

Chitosan‐Derived NiO‐Mn2O3/C Nanocomposites as Non‐Precious Catalysts for Enhanced Oxygen Reduction Reaction

“…From Figure , it was observed that the XRD pattern of NiO‐Mn 2 O 3 /C matches with the combination of XRD of Mn 2 O 3 , NiO, and graphitic carbon. The diffraction peaks at 2 θ values of 26.84 o and 43.14 o corresponding to (002) and (101) reflection planes, respectively, indicated the formation of graphitic‐type carbon after pyrolysis . The diffraction peaks at 2 θ values of 32.94 o , 38.34 o , 45.21 o , 49.38 o , 55.36 o , and 66.24 o match with the diffraction pattern of standard Mn 2 O 3 , and correspond to (111), (200), (220), (311), (222), and (400) crystal planes of face‐centered‐cubic (fcc) Mn 2 O 3 , respectively .…”

Nanoporous carbon synthesized from grass for removal and recovery of hexavalent chromium

“…During pyrolysis metallic particles are produced due to carbothermal reduction of FeCl 3 salts. These particles help in formation of porous nanostructured carbon materials [12]. After removing Fe, the NPC was acid functionalized to introduce active oxygen containing groups on the surface.…”

Formation of 3D graphene foams on soft templated metal monoliths

“…However, the oxidation and exfoliating processes introduce defects into the graphene structure disrupting the delocalized sp 2 network, adversely affecting its physical and electrical properties and decreasing its chemical stability. 25,26 By contrast, the 'hard' template approach typically involves chemical vapor deposition (CVD) onto commercially available nickel foams with an average pore size in excess of 50 µm. 17,27,28,12 The template CVD graphene produced typically has much higher electrical conductivity than that of graphene derived from graphite oxide however, yields are much lower than those found in graphene oxide self-assembly routes.…”