Amine-Functionalized Mesoporous Silica @ Reduced Graphene Sandwichlike Structure Composites for CO₂ Adsorption

Abstract

Amine-functionalized mesoporous silica @ reduced graphene (denoted as mSiO 2 @rGO-NH 2 ) sandwichlike structure materials are synthesized via an oil−water stratification method and the self-assembled monolayers on mesoporous support (SAMMS) technique. The resulting mSiO 2 @rGO-NH 2 materials exhibit excellent performance for physical and chemical synergetic adsorption of CO 2 gas. Among them, with optimal contents of −NH 2 , the corresponding mSiO 2 @rGO-NH 2 -0.6 material is able to exhibit the high CO 2 adsorption capacity of 3.64 mmol g −1 (0 °C, 1 bar), high CO 2 /N 2 selectivity up to 47.6 (0 °C, 1 bar), moderate heat of adsorption, as well as good stability. Such improved adsorption performance is due to the reasonably design of sandwichlike structure containing multilevel pores (macro-/meso-/micropores), highly dispersed −NH 2 groups, as well as the graphene sheets with good thermal conductivity, which enable the mSiO 2 @rGO-NH 2 -0.6 material to shorten the diffusion path of CO 2 , offer plenty of accessible amino sites, as well as transport adsorption heat effectively. Thus, the mSiO 2 @rGO-NH 2 sandwichlike structure materials can selectively adsorb acid gas CO 2 and have great application prospects in CO 2 adsorption.

Comparison between Linear and Branched Polyethylenimine and Reduced Graphene Oxide Coatings as a Capture Layer for Micro Resonant CO2 Gas Concentration Sensors

“…However, at higher concentration values, the proportion of adsorption capacity is progressively reduced until it reaches its saturation point [49,50]. In the case of the rGO with linear PEI, a higher adsorption capacity of 8.10 mmol/g of CO2 at 273 K and low pressure has been reported [30,40]. Due to this, the results obtained show a higher adsorption ratio from 0.05 % to 0.15 %, followed by a progressive reduction in the frequency deviation.…”

“…Figure 4 shows the SEM micrographs of the quartz crystal's surface for the three coatings investigated. This method is widely used to allow for the observation of the quality of the deposited material, and for the verification of the area of the quartz crystal that has been coated [40,41]. The uniformity is similar between the deposited PEI coatings, which is a critical factor to be able to make an equitable comparison and to maintain the high Q factor of the crystals.…”

One-pot synthesis of organic polymer functionalized mesoporous silicas

“…[63] The maximum separation factor of this hybrid zeolite membrane for CO2/CH4 was 5.72 at 313 K and at 1.5 bar. Liu et al have obtained remarkable selectivity in the separation of CO2/N2 gas mixture using amine-functionalized mesoporous silica @ reduced graphene sandwichlike structure materials [64]. The CO2/N2 separation factor of 47.6 at 0°C and at 1 bar was found for these systems.…”

Dual Stimuli-Responsive Copper Nanoparticles Decorated SBA-15: A Highly Efficient Catalyst for the Oxidation of Alcohols in Water

“…To ensure better incorporation of metal nanoparticles, functional groups are often decorated onto the mesoporous silica surface through a surface modification process [ 17 , 18 , 19 ]. The grafted functional groups such as amine, thiol, cyano, vinyl, alkyl, and phenyl can act as anchors to enhance the interaction between the silica wall and the metal precursor [ 20 , 21 , 22 , 23 ]. Here, we used trimethoxy silyl propyl methacrylate (TMSPM) for the surface functionalization of SBA-15.…”