Novel NiMgOH-rGO-Based Nanostructured Hybrids for Electrochemical Energy Storage Supercapacitor Applications: Effect of Reducing Agents

• Main Authors: Konda Shireesha, Thida Rakesh Kumar, Tumarada Rajani, Chidurala Shilpa Chakra, Murikinati Mamatha Kumari, Velpula Divya, Kakarla Raghava Reddy
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Crystals
• Subjects: NiMgOH; carbon nanomaterials; nanostructured hybrid electrodes; electrochemical properties; specific capacitance; energy storage supercapacitors
• Online Access: https://www.mdpi.com/2073-4352/11/9/1144

This paper describes the synthesis and characterization of NiMgOH-rGO nanocomposites made using a chemical co-precipitation technique with various reducing agents (e.g., NaOH and NH₄OH) and reduced graphene oxide at 0.5, 1, and 1.5 percent by weight. UV-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, a particle size analyzer, and cyclic voltammetry were used to characterize the composite materials. The formation of the NiMgOH-rGO nanocomposite with crystallite sizes in the range of 10–40 nm was inferred by X-ray diffraction patterns of materials, which suggested interlayers of Ni(OH)₂ and Mg(OH)₂. The interactions between the molecules were detected using Fourier-transform infrared spectroscopy, while optical properties were studied using UV-visible spectroscopy. A uniform average particle size distribution in the range of 1–100 nm was confirmed by the particle size analyzer. Using cyclic voltammetry and galvanostatic charge/discharge measurements in a 6 M KOH solution, the electrochemical execution of NiMgOH-rGO nanocomposites was investigated. At a 1 A/g current density, the NiMgOH-rGO nanocomposites prepared with NH₄OH as a reducing agent had a higher specific capacitance of 1977 F/g. The electrochemical studies confirmed that combining rGO with NiMgOH increased conductivity.