Won-Chun Oh
Abstract
Due to its unique atom-thick 2D structure and remarkable physicochemical properties, graphene has been sparked a flurry of research into its optical, electronic, thermal, and mechanical properties. In particular, a great deal of recent attention has been attracted to explore graphene and graphene composites for photoelectrochemical applications. Recently, much works have been done on attempting to design and prepare novel graphene-based materials for a wide range of applications in photo-electrochemistry, ranging from photoelectrochemical solar cells, photocatalytic decomposition of organic pollutants, and H2 evolution. In this feature article, we summarize the state of research on graphene-based materials for photo-electrochemistry. The prospects and further developments in this exciting field of graphenebased materials are also discussed. Graphene—a one-atom-thick planar sheet of carbon atoms arranged during a honeycomb crystal lattice—continues to make one among the foremost active areas of condensed matter research. Its properties, including high mechanical stiffness and strength (when defect free, thus so far only over small distances like microns), including high electrical and thermal conductivity, make graphene an exciting prospect for a number of future applications in nanoelectronics, thermal management and energy storage devices. One key to optimizing this potential is that the ability to tune the properties of graphene through chemical functionalization. The aim of this focus issue of latest Journal of Physics is to supply a snapshot of a number of the newest state-of-the-art techniques now getting used to control and treat the fabric . Graphene oxide was prepared from natural crystalline graphite powder by Hummers method. Thus, 2 g of graphite powder, 1 g of NaNO3, and 46 ml of concentrated H2SO4 were mixed together during a flask placed into an ice bath and stirred for 30 min. Then, 6 mg of KMnO4 was added into the mixture by portions to stop the temperature rise above 20 °C and stirred for two h. Subsequently, the temperature of suspension was delivered to 35 °C and maintained at this level for an hour. Then, 92 ml of water was added at ambient temperature into the brownish gray paste, causing violent effervescence and a rise of temperature to 98 °C. The obtained diluted, brown color suspension was kept at this temperature for several minutes; during this point , the answer changed its color to bright yellow; and after this, the suspension was further diluted with 250 ml of warm water and treated with 20 ml of H2O2 to scale back the residual permanganate and manganese dioxide. While the suspension was still warm, it had been vacuum filtered to avoid precipitation of side products. The filter cake was washed with warm water and centrifuged on a Sigma 6-16 K centrifuge (SciQuip, USA). The obtained sediment was freeze-dried on a Gamma 1-16 LSC plus machine (Martin Christ Gefriertrocknungsanlagen GmbH). In chemistry, photocatalysis is that the acceleration of a photoreaction within the presence of a catalyst. In catalysed photolysis, light is absorbed by an adsorbed substrate. In photogenerated catalysis, the photocatalytic activity (PCA) depends on the power of the catalyst to make electron–hole pairs, which generate free radicals (e.g. hydroxyl radicals: •OH) ready to undergo secondary reactions. Its application was made possible by the invention of water electrolysis by means of titanium oxide (TiO2). Research in photocatalysis subsided for over 25 years thanks to lack of interest and absence of practical applications. However, in 1964, V.N. Filimonov investigated isopropanol photooxidation from ZnO and TiO2; at round the same time, Kato and Mashio, Doerffler and Hauffe, and Ikekawa et al. (1965) explored oxidation/photooxidation of CO2 and organic solvents from ZnO radiance. a couple of years later, in 1970, Formenti et al. and Tanaka and Blyholde observed the oxidation of varied alkenes and therefore the photocatalytic decay of laughing gas (N2O), respectively.