Graphene Oxide−Periodic Mesoporous Silica Sandwich Nanocomposites with Vertically Oriented Channels

Abstract

This paper describes the synthesis and characterization of single-layer graphene oxide-periodic mesoporous silica sandwich nanocomposites. Through a comprehensive exploration of the synthesis conditions, it has proven possible to create the first example of a graphene oxide-periodic mesoporous silica nanocomposite in which hexagonal symmetry PMS film grows on both sides of the graphene oxide sheets with the mesoporous channels vertically aligned with respect to the graphene oxide surface. The formation of this novel architecture is found to be very sensitive to pH, the ratio of surfactant template to graphene oxide, the amount of silica precursor, and the temperature of the synthesis. On the basis of the collected data of a multi-technique analysis, it is proposed that the mode of formation of the nanocomposite involves the co-assembly of silicate-surfactant admicelles on opposite sides of graphene oxide platelets acting thereby as a template for growth of vertical mesopores off the platelet surface. These composites showed semiconductive behavior with electrical conductivity sensitively responding to analyte vapor exposure. The discovery of graphene oxide-periodic mesoporous silica sandwich nanocomposites will provide new opportunities for research that exploits the synergism of the graphene oxide and periodic mesoporous silica parts.

NIR‐Triggered Synergic Photo‐chemothermal Therapy Delivered by Reduced Graphene Oxide/Carbon/Mesoporous Silica Nanocookies

“…MSN with pore channels was next grown by controlled hydrolysis of tetraethylorthosilicate (TEOS) via a micelle mechanism that involved CTAB as a surfactant. [ 19 ] To incorporate carbon into the composite, we fi rst simultaneously formed polystyrene by polymerizing (using an initiator, n -octane,2,2′-azobis(2-amidinopropane) dihydrochloride (AIBA)) styrene monomers inside the pore channels during MSN formation. We next sulfonated and then pyrolyzed polystyrene in high temperature argon to form carbon deposit on the channel wall.…”

Green Synthesis and Characterization of Graphite Oxide by Orthogonal Experiment

“…Generally, the degree of remaining conjugation in GO sheets could be determined by the λ max of UV-Vis spectrum. The more conjugated π→π* transitions, the less energy needs to be used for the electronic transition, which results in a higher λ max [37]. As shown in Figure 5, two absorption bands around 227.5 nm and 292.5 nm were observed for both the IGO and HGO.…”

Synthesis of an efficient white-light photocatalyst composite of graphene and ZnO nanoparticles: Application to methylene blue dye decomposition

“…Conductivity (S/m) Graphene/Al2O3 [64] 1000 CNT-Fe/Co-MgAl2O3 [65] 150-180 CNT-Fe-Al2O3 [65] 40-80 Graphene/SiO2 [66] 45 CNT-Co-MgO [65] 20 ZnO/C core-shell nanorods [45] 1.6-63 Graphene/SiO2 [67] 4 Graphene/Mn2O3 [68] 10 −5 -10 −6 GZN composite (our work) ∼54000 conductivity is higher than those of other composite materials [45,[64][65][66][67][68] (Table 1). High electrical conducting composite materials of semiconducting ZnO nanoparticles and graphene are useful for various types of applications such as solar and fuel cells and photocatalysis.…”