Preliminary evaluation of resorcinol-formaldehyde carbon gels for water pollutants removal

Abstract

The present work was aimed to evaluate the suitability of resorcinol-formaldehyde carbon gels as adsorbent for water pollutants removal. The carbon gels were characterized using N2 adsorption-desorption isotherm for specific surface area, and Fourier transform infrared (FTIR) for surface functional groups. Methylene blue and cesium were employed as model water pollutants. Results show that the un-oxidized carbon gel, despite its lower specific surface area (333 m2/g) displayed a 118 mg/g removal of methylene blue, that is higher than 35 mg/g by the oxidized carbon gel (418 m2/g). The evaluation of adsorption kinetics revealed a lower pseudo-first order rate constant of 0.088 h-1 for 10 mg/L methylene blue adsorption. A positive effect of surface oxidation was demonstrated for cesium adsorption. On molar basis, however, the oxidized carbon gel exhibits a selective removal towards methylene blue compared to cesium. Carbon gel is a promising candidate for water pollutants removal, and further treatment needs to be sought to boost its performance.

Clarification of the Effects of Oxygen Containing Functional Groups on the Pore Filling Behavior of Discharge Deposits in Lithium–Air Battery Cathodes Using Surface-Modified Carbon Gels

“…In this study, CGs were employed as the porous carbon material for cathodes because they have a highly tunable and stable pore structure, which is practically an aggregation of carbon nanoparticles connected by chemical bonds. Their surfaces can be easily modified because they have numerous edge sites within their structure. , CGs were used as a model porous carbon material for the investigation of the effect of heat treatment in the range of 1000–2200 °C on their structure and their cycle performance as a LAB cathode . However, the effects of the OCFGs and edge H within them on their discharge–charge behavior was not investigated in detail because most OCFGs in the CGs were removed by heat treatment above 1000 °C, and their surface properties were measured only by a TPD analysis conducted up to a maximum temperature of 1000 °C.…”

Resorcinol-Formaldehyde Carbon Gels Adsorption: A Commentary

“…The physical oxidation in air forms phenolic and carbonyl groups, while chemical oxidation with nitric acid establishes carboxylic group on the carbon surface. 18 The physical oxidation is usually held at a higher temperature than chemical oxidation, but the former does not require a washing post-treatment. 19 Figure 3 illustrates the synthesis of carbon gel.…”

“…[21][22] The post-treatment using HNO 3 increases the mesoporosity of carbon gel at the expense of slight decrease in surface area. 18,21,23 Xiao and co-workers 21 Table 2. Adsorption properties of carbon gels.…”