Development of Graphitic Carbon Nitride-Encapsulated SrFe2O4 Spinel Nanocomposite Electrode for Enhancing Supercapacitor and Oxygen Evolution Applications Silambarasan Kuppusamy, Dinesh Selvakumaran, Kumaresan Lakshmanan, Mohd Khairul Bin Ahmad Energy and Fuels, 2024 In the past few years, there has been a notable upswing in the excitement surrounding bifunctional materials, primarily due to their versatility in accommodating energy storage and conversion needs. One class of materials that garnered considerable attention is strontium ferrite nanoparticles (NPs), which are known for their remarkable electrochemical properties stemming from their exceptional physical and chemical characteristics. In this study, we have synthesized a novel, cost-effective, and highly efficient composite electrode designed for dual functionality in supercapacitor (SC) and oxygen evolution reaction (OER) applications in alkaline environments. Herein, we prepared SrFe2O4@g-C3N4 composite through a coprecipitation and pyrolysis method, resulting in featuring a porous g-C3N4 matrix and strontium (Sr) spinel structure. The composite materials were thoroughly characterized using techniques such as powder X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy. The SrFe2O4@g-C3N4 electrode exhibited outstanding pseudocapacitive behavior and delivered a specific capacitance of 1055 F/g at a current density of 1 A/g. Remarkably, it displayed a capacitance retention of 93% even after 5000 galvanostatic charge–discharge (GCD) cycles. Furthermore, in comparative assessments with bare SrFe2O4 or g-C3N4 electrodes, the SrFe2O4@g-C3N4 composite electrode displayed superior and stable electrocatalytic performance. It required minimal overpotentials (only 170 mV) to achieve a current density of 10 mA cm–2 during the OER. These results emphasize the substantial potential of Sr-based nanocomposites as auspicious materials for applications in supercapacitors and as stable electrocatalysts.
Plasmon Effect of Ag Nanoparticles on TiO2/rGO Nanostructures for Enhanced Energy Harvesting and Environmental Remediation Seenidurai Athithya, Valparai Surangani Manikandan, Santhana Krishnan Harish, Kuppusamy Silambarasan, Shanmugam Gopalakrishnan, Hiroya Ikeda, Mani Navaneethan, Jayaram Archana Nanomaterials, 2023 We report Ag nanoparticles infused with mesosphere TiO2/reduced graphene oxide (rGO) nanosheet (TiO2/rGO/Ag) hybrid nanostructures have been successfully fabricated using a series of solution process synthesis routes and an in-situ growth method. The prepared hybrid nanostructure is utilized for the fabrication of photovoltaic cells and the photocatalytic degradation of pollutants. The photovoltaic characteristics of a dye-sensitized solar cell (DSSC) device with plasmonic hybrid nanostructure (TiO2/rGO/Ag) photoanode achieved a highest short-circuit current density (JSC) of 16.05 mA/cm2, an open circuit voltage (VOC) of 0.74 V and a fill factor (FF) of 62.5%. The fabricated plasmonic DSSC device exhibited a maximum power conversion efficiency (PCE) of 7.27%, which is almost 1.7 times higher than the TiO2-based DSSC (4.10%). For the photocatalytic degradation of pollutants, the prepared TiO2/rGO/Ag photocatalyst exhibited superior photodegradation of methylene blue (MB) dye molecules at around 93% and the mineralization of total organic compounds (TOC) by 80% in aqueous solution after 160 min under continuous irradiation with natural sunlight. Moreover, the enhanced performance of the DSSC device and the MB dye degradation exhibited by the hybrid nanostructures are more associated with their high surface area. Therefore, the proposed plasmonic hybrid nanostructure system is a further development for photovoltaics and environmental remediation applications.
