Synthesis and application of tuneable carbon–silica composites from the microwave pyrolysis of waste paper for selective recovery of gold from acidic solutions

Abstract

<p>Microwave pyrolysis bio-oil from waste paper and K60 silica gel have been utilised to synthesise mesoporous carbon–silica composites with uniquely tuneable surface properties for the selective recovery of gold from acidic solutions.</p>

Graphitic mesoporous carbon-silica composites from low-value sugarcane by-products for the removal of toxic dyes from wastewaters

“…By contrast, at 800°C, the contribution of aliphatic carbon is greatly diminished and the material is dominated by C-O (C-O-C, C-O-H). In all cases, oxygen is the bridge between the carbon layer and the silica, leading to the observed C–O–Si bonds (288.8 eV), and this is consistent with observations of the CSC materials [ 49 ]. XPS demonstrated that the proportion of C=C sp 2 (284.2 eV) on the surface of all molasses-based CSC materials was low and this is in contrast with CSC materials produced from bio-oil [ 49 ].…”

“…In all cases, oxygen is the bridge between the carbon layer and the silica, leading to the observed C-O-Si bonds (288.8 eV), and this is consistent with observations of the CSC materials [49]. XPS demonstrated that the proportion of C=C sp 2 (284.2 eV) on the surface of all molasses-based CSC materials was low and this is in contrast with CSC materials produced from bio-oil [49]. XPS for O1S and Si2P of CSC400, CSC600 and CSC800 are available in the electronic supplementary material.…”

“…Importantly, the unique range of functional groups present in carbon matrix of molasses-based CSC such as C-O-C, C–OH, C=O and COO- could also play a vital role in the adsorption mechanism of the dye [ 63 ]. The proportions of these functionalities clearly demonstrate significant differences over other CSC materials in the literature [ 49 ]. This is especially true for CSC600 and CSC800, where XPS demonstrates the formation of C=O at 600°C, while C-O-C functional groups are dominated at 800°C.…”

“…XPS C1S demonstrates contributions from C=C, C-C, C-O, C=O and C-O-Si groups on the surface of CSC at 284.2, 284.9, 286.2, 287.2 and 288.8 eV binding energies, respectively [32,49]. XPS results also indicate that CSC400 carbon surface is still dominated by aliphatic carbon functionalities (C-C sp3, 284.9 eV).…”

Advances in Microwave Synthesis of Nanoporous Materials

“…[ 241–243 ] This review is focused on the microwave‐assisted synthesis of the selected groups of nanomaterials. However, many papers devoted to porous composites prepared by means of MW method, e.g., graphene/TiO 2 , [ 244 ] graphene/Co 3 O 4 , [ 245 ] ZnO/graphene, [ 246 ] CoSe 2 /reduced graphene oxide (rGO), [ 247 ] rGO/MOF, [ 248 ] BiOI/g‐C 3 N 4 , [ 249 ] MCM‐41/Cu‐MOF, [ 250 ] carbon/SiO 2 [ 251,252 ] composites have been also published. There are still great opportunities in the design and microwave‐assisted synthesis of various composite materials, especially those combining 1D and 2D nanomaterials into 3D porous nanostructures.…”