RGO@β-CaSiO3:Sm3+ nanocomposites for super capacitors, biosensor and w-LEDs applications

• Published in: Ceramics international Vol. 50; no. 22; pp. 47067 - 47088
• Main Authors: Nadar, Nandini Robin, Deepak, J., Sharma, S.C., Krushna, B.R. Radha, Pruthviraj, I.S., George, Augustine, Ponnazhagan, K., das, Chandan, Sargunam, B., Anand, D.G., Manjunatha, K., Yun Wu, Sheng, Nagabhushana, H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.11.2024
• Subjects: Biosensor; Electrochemical studies; Hydrothermal; Reduced graphene oxide; Structural characterization; Super capacitor; β-CaSiO3:Sm3; Electrochemical studies; Super capacitor; Structural characterization; Biosensor; β-CaSiO3:Sm3; Reduced graphene oxide; Hydrothermal
• ISSN: 0272-8842
• DOI: 10.1016/j.ceramint.2024.09.057

Sm3+ doped β-wollastonite (β-CaSiO3) nanoparticles (β-CSO:Sm3+ NPs) are effectively synthesized through agricultural waste. Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), photoluminescence (PL), and electrochemical analyses are utilized to validate the synthesis, structural, luminescence, and supercapacitor characteristics of the NPs. The diffraction analysis unveiled a monoclinic crystal structure nested within a rhombohedral lattice system in the synthesized samples. The excitation spectrum of β-CSO doped with 7 mol % of Sm3+ ions exhibited a prominent peak at 404 nm, while the emission spectrum revealed four distinct peaks. The most intense emission peak, observed at 645 nm, corresponds to the radiative transition from 4G5/2 to 6H9/2 states of Sm3+ ions. Analysis of emission spectra across different doping concentrations identified 7 mol % as the optimal optical doping concentration. The phenomenon of concentration quenching is attributed to dipole-dipole interactions. Exploration into energy storage and biosensor technologies is crucial for addressing societal challenges, expanding scientific understanding, and promoting sustainable progress across various domains including energy and healthcare. In this investigation, we successfully synthesized pristine RGO@β-CSO:Sm3+ nanocomposites (NCs) using a hydrothermal approach. Through cyclic voltammetry (CV) analysis, it is observed that these NCs exhibited markedly higher specific capacitance (Csp) of 152.15 F/g at a scan rate of 2 mV/s. Moreover, they demonstrated a notable energy density of 35.77 Wh/kg, alongside enhanced capacity retention of 82.27 % and exceptional Coulombic efficiency of 95.77 % compared to undoped RGO@β-CSO. Subsequently, these NCs are utilized to fabricate modified carbon paste electrodes (MCPE) for electrochemical dopamine (DA) detection at an optimal pH of 7.4. The modified electrodes demonstrated favorable current responses for DA voltammetry, achieving low limits of detection (LOD) and quantification (LOQ) values of 9.226 μM and 30.75 μM, respectively. Additionally, they showcased improved selectivity between dopamine and uric acid, with a deterioration rate of only 97.83 % over 20 cycles. These findings suggest that the developed electrode holds significant promise for applications in supercapacitors and dopamine detection, thereby contributing to advancements in energy storage technology and biosensor applications. [Display omitted] •Economically feasible, reduced graphene oxide based β-CaSiO3:Sm3+ nanocomposites are synthesized from agricultural and food waste materials.•Structural, morphological, luminescence and electrochemical studies are performed using XRD, FE-SEM, TEM, XPS, PL, IQE CH instruments.•Electrochemical studies of synthesized RGO@β-CaSiO3:Sm3+ nanocomposites were performed to evaluate parameters like specific capacitance, energy density, coulombic efficiency, capacity retention etc.•Biosensor studies of the synthesized materials, using dopamine and uric acid proves to be a boon for biomedical applications.•Reduced graphene oxide based β-CaSiO3:Sm3+ nanocomposite can be used for future technologies, particularly in wearable/integrated electronic devices, smart sensor opto-electronic devices.