Fabrication of reduced graphene oxide/metal (Cu, Ni, Co) nanoparticle hybrid composites via a facile thermal reduction method

Abstract

A facile thermal reduction method has been proposed for the fabrication of reduced graphene oxide/metal (e.g., Cu, Co, Ni) nanoparticle hybrid composites at 500 o C for 90 minutes under flowing argon due to the release of reductive gas by thermolysis of graphene oxide. The loading amount and 10 dispersion of metal nanoparticles could be easily controlled via the mass ratio of graphene oxide/metal nitrate precursor and the calcination temperature. The results show that with the increase of graphene oxide/metal nitrate mass ratio, it is easier to obtain pure metallic nanoparticles with high 15 dispersion and small nanoparticle size.

Interface Engineering of Graphene-Supported Cu Nanoparticles Encapsulated by Mesoporous Silica for Size-Dependent Catalytic Oxidative Coupling of Aromatic Amines

“…PXRD patterns of the series of Cu–GO@m-SiO 2 - A , B , and C nanocomposites are shown in Figure S5, Supporting Information. Cu–GO@m-SiO 2 - A and B exhibited broad diffraction peaks in the range of 2θ = 15°–35°, which could be assigned to the graphene nanosheet-supported metal NPs tightly covered by mesoporous silica (m-SiO 2 ) layers. , One strong peak along with two very weak diffraction peaks appeared at 2θ = 43.3°, 50.4°, and 74.1° in Cu–GO@m-SiO 2 - A , B catalysts which could be nicely indexed to the (111), (200), and (220) crystalline reflection planes, respectively, corresponding to cubic Cu(0)-NPs (JCPDS card no. 04-0836). ,, In contrast, the Cu–GO@m-SiO 2 - C material exhibited three distinct peaks; in addition, other diffraction peaks were noticed at 2θ = 16.2°, 17.5°, 31°, 32.4°, 39.8°, 50.0°, 53.6°, and 57.3°, which could be readily assigned to (111), (003), (021), (113), (024), (033), (220), and (223) planes, respectively, of (Cu 2 Cl­(OH) 3 ) (JCPDS card no.…”

Optimum Preferential Oxidation Performance of CeO2–CuOx–RGO Composites through Interfacial Regulation

“…22−26 Wang and co-workers have obtained reduced graphene oxide (RGO)/metal (Cu, Ni, and Co) nanohybrid composites by a facile thermal reduction method. 27 For copper oxide/RGO nanocomposites, as reported by the Dolui group, 28 the integration of nanoparticles into the RGO leads to synergetic effects between the RGO nanosheets and the nanoparticles, which improves the catalytic activity for the reduction of 4-nitrophenol and the functionality of the nanocomposites. Having these literature data in mind, we proposed that (i) when decorating with a low content of RGO, one may develop a new facile path to increase the content of the active Cu + species with an enhanced synergetic effect in the CuO−CeO 2 system for the CO-PROX reaction and moreover (ii) during the interfacial regulation, the CuO species located at the interface of the CuO−CeO 2 system generally exhibit different types of coordination environments, leading to a promoted synergetic effect of the components.…”

“…Integrating the active Cu + sites on the CuO–CeO 2 -based catalysts could be achieved through interfacial regulation with the help of graphene; this is because graphene has unique characteristics such as high electronic mobility and tremendous specific surface area and most importantly because the presence of graphene is favorable for the reduction of metal oxide to generate more reductive species. − Wang and co-workers have obtained reduced graphene oxide (RGO)/metal (Cu, Ni, and Co) nanohybrid composites by a facile thermal reduction method . For copper oxide/RGO nanocomposites, as reported by the Dolui group, the integration of nanoparticles into the RGO leads to synergetic effects between the RGO nanosheets and the nanoparticles, which improves the catalytic activity for the reduction of 4-nitrophenol and the functionality of the nanocomposites.…”

Synthesis of oxygen functionalized carbon nanotubes and their application for selective catalytic reduction of NOx with NH3

“…Various carbon materials (graphene, graphene oxide, reduced graphene oxide, carbon nanotubes (CNTs), and activated carbon) have been used as support materials in various elds such as catalysis, 1 fuel cells, 2 and water purication 3 due to their high specic surface areas and chemical stability. 4,5 When carbon materials are applied as supports, they prevent aggregation of the catalyst material and increase the catalytic active sites, which result in enhanced catalytic activities at the temperatures below 200 C. 1,4 Although graphene oxide can improve the dispersion of active materials on the surface because of the abundant oxygen functional groups, they also accelerate the thermal decomposition at the temperatures above 150 C. 6 Reduced graphene oxide is relatively stable at high temperatures compared with graphene oxide because the surface oxygen functional groups have been reduced. However, reduced graphene oxide is prone to oxidation under long exposures to high-temperature oxygen atmospheres.…”