Hydrothermal synthesis, characterization, and KOH activation of carbon spheres from glucose

Deactivation of sulfonated hydrothermal carbons in the presence of alcohols: Evidences for sulfonic esters formation

“…Sulfonated hydrothermal carbons, either prepared in two steps [18] or in one-pot synthetic method 3 [19], have been also used as acid catalysts for esterification reactions. Furthermore, hydrothermal carbon synthesis is a very versatile method to prepare materials with different porous structures [20][21][22][23][24] and shapes, such as hollow capsules [25][26][27], nanowires [28] or nanotubes [29]. Recently, it has been demonstrated by our group that HT carbon films can be also coated on a structured macroscopic support such as graphite felt [30].…”

Diamond-Like Carbon Nanofoam from Low-Temperature Hydrothermal Carbonization of a Sucrose/Naphthalene Precursor Solution

“…For example, the hydrothermal carbonization was performed for cellulose in the 220-250 °C range [40], for glucose between 170 and 500 °C [19,[41][42][43][44], for sucrose at 190 °C [45] and for starch at 600 °C [46]. Process times were typically between 4 and 12 h. For some of the materials, the graphitic nature has been improved by annealing the sample after synthesis.…”

A Review of Hydrothermal Carbonization of Carbohydrates for Carbon Spheres Preparation

“…The size of carbon spheres increased with the elevated concentration of glucose solution within a certain concentration range [30]. When the concentration of glucose increased from 0.5 to 1 mol/L, the diameters grew from 1.2 to 1.4 μm, if HTC experiments were carried out at a constant temperature of 190ºC and dwell time of 4.5 h [31].…”

“…For instance, when HTC experiments were carried out at a constant concentration of 0.5 mol/L glucose and 160°C, as the residence time increased from 2 to 4, 6, 8, and 10 h, the diameters grew from 0.2 to 0.5, 0.8, 1.1, and 1.5 μm [42]. However, if the reaction time was too long, the produced carbon spheres fused, giving rise to particles with irregular shapes [30].…”

“…This process was called carbonization [31]. When the growth stopped, carbon materials formed from glucose had a condensed furanic system consisting of a hydrophobic core and a hydrophilic shell embedded with levulinic acid [30].…”