The Preparation of Alumina Particles Wrapped in Few-layer Graphene Sheets and Their Application to Dye-sensitized Solar Cells

Abstract

Alumina particles wrapped in few-layer graphene sheets were prepared by calcining aluminum nitride powders under a mixed gas flow of carbon monoxide and argon. The graphene sheets were characterized by powder Xray diffraction (XRD), Raman spectroscopy, electron energy loss spectroscopy, and high-resolution transmission electron microscopy. The few-layer graphene sheets, which wrapped around the alumina particles, did not exhibit any diffraction peaks in the XRD patterns but did show three characteristic bands (D, G, and 2D bands) in the Raman spectra. The dye-sensitized solar cell (DSSC) with the alumina particles wrapped in fewlayer graphene sheets exhibited significantly improved overall energy-conversion efficiency, compared to conventional DSSC, due to longer electron lifetime.

Graphene-wrapped hierarchical TiO2 nanoflower composites with enhanced photocatalytic performance

“…19,20,22 Graphene-wrapping of other materials is a more recent method for hybridizing graphene to form composites, and has found use in Li-ion batteries, 23,24 supercapacitors, 25,26 fuel cells, 27 and solar cells. 28 This method of hybridization allows for an increased amount of contact between graphene and the photocatalyst, thus improving charge transport characteristics. 29,30 Unfortunately, graphene wrapping of metal oxides oen involves additional functionalization of the material surface which is an undesirable intermediate step.…”

Water flattens graphene wrinkles: laser shock wrapping of graphene onto substrate-supported crystalline plasmonic nanoparticle arrays

“…17,18 The graphene coating on metallic nanowires was also reported to have increased thermal and electrical conductivities for better thermal management and higher speed in future electronic devices. 19 Strategies for integration of graphene with various nanomaterials include in situ wrapping of graphene while nanostructures are being formed by chemical reactions [20][21][22][23][24][25][26][27][28][29] or post-growth ex situ graphene wrapping of nanostructures. 30,31 Ex situ graphene integration techniques, [32][33][34][35] such as wet chemical transfer, are the most commonly employed approaches, due to their flexibility of transferring graphene deterministically onto various target surfaces with controlled graphene thickness and integrity.…”