Fabrication of Nanocomposites based-Reduced Graphene Oxide for Supercapacitors

Nanotechnology drives various growing fields of science and technology that engage with manipulating matter on an incredibly small scale (less than 100 nanometers), including the energy storage, energy production, and consumer electronics. Development of energy storage such as supercapacitors and batteries, needs materials with a diversity of electrical, chemical, and mechanical properties. Graphene, as both the lightest and strongest material known to exist, also has remarkable physical and chemical properties, including a large surface area, high electrical and thermal conductivities, optically transparent, excellent mechanical strength, flexibility, and impermeable to gas [1], [2], [3], [4]. Reduced Graphene Oxide (rGO) has been used as an electrode material in supercapacitors [5], [6], showing a promising increase in energy density while maintaining long cycle life [7] and open the opportunity for self-charging supercapacitors [8]. rGO-based supercapacitors are capable of storing twice as much energy as traditional capacitors and can be charged-discharged hundreds of thousands without significant performance degradation [9]. Ceramics are also considered an ideal material for supercapacitors due to their chemical stability because they have a longer cycle life, higher power densities, and lower equivalent series resistance (ESR). Magnesium titanate (MgTiO3) as one of the popular dielectric ceramics, has been implemented in the industry for resonator dielectrics and filter applications in communication and radar systems [10], [11], due to its relatively high permittivity, high-quality factor, and suitable density [12].

By incorporating other ceramics materials into rGO, novel properties are attractive to combine, and the resulting composite can be used to increase rGO’s performance as a supercapacitor. Combining graphene and ceramic materials has the potential to become a powerful energy storage device [13] with excellent electrical and thermal conductivity, creating an ideal supercapacitor energy storage [14], such as high power density, long service life, excellent temperature stability, and high corrosion resistance, are essential features.

Inspired by research results on graphene/ceramic as supercapacitors, we develop a new electrode material, rGO/(Mg1-xZnx)TiO3 nanocomposite, for supercapacitor applications. In previous research by Sriramraj et al [15], they synthesized rGO/MgTiO3 without doping ion Zn2+ and produced the specific capacitance 117.8 F/g. In this work, we showed the preparation of (Mg1-xZnx)TiO3 from the MgTiO3 compound as a nanocomposite electrode material with rGO and its application for supercapacitor electrodes, which so far has been no report on its use. We synthesized the rGO for the nanocomposite using a green reductor of ascorbic acid. Green reduction of GO forms rGO and assists in removing oxygen functional groups within a relatively short time, delivering elements with a high C/O ratio [16], [17].