Facile Synthesis and Characterization of Few-Layer Multifunctional Graphene from Sustainable Precursors by Controlled Pyrolysis, Understanding of the Graphitization Pathway, and Its Potential Application in Polymer Nanocomposites

Abstract

The key feature of the present work is the dexterous utilization of an apparently destructive process, pyrolysis, for the synthesis of the most esteemed nanomaterial, graphene. This work is an attempt to synthesize graphene from nonconventional sources such as tannic acid, alginic acid, and green tea by a controlled pyrolysis technique. The precursors used in this work are not petroleum-derived and hence are green. A set of pyrolysis experiments was carried out at different temperatures, followed by a thorough step-by-step analysis of the product morphology, enabling the optimization of the graphitization conditions. A time-dependent morphological analysis was also carried out along with isothermal thermogravimetric studies to optimize the ideal pyrolysis time for graphitization. The specific capacitance of the graphene obtained from alginic acid was 315 F/g, which makes it fairly suitable for application as green supercapacitors. The same graphene was also used to fabricate a rubber-latex-based flexible supercapacitor film with 137 F/g specific capacitance. The graphene and graphene-based latex film exhibited room-temperature magnetic hysteresis, indicating their ferromagnetic nature, which also supports their spintronic applications.

Amorphous FeOOH Anchored on Boron and Nitrogen Codoped Carbon Nanotubes for Fenton-like Oxidation of Sulfamethoxazole

“…46 The results suggest a strong bonding network of B−N into the structure at a high temperature. Figure 3e 40,47 Furthermore, the resulting spectrum of Fe 2p deconvolution reveals two peaks for Fe 3+ (710.43 and 724.23 eV) along with two additional shake-up satellites at 718.8 and 732.2 eV and are in agreement with the reported literature. 48−50 Thermal gravimetric analysis (TGA/DTG) curves of all FeOOH-1∼6@BNG samples were acquired in the air atmosphere to evaluate the phase changing and reactions of FeOOH QDs under the influence of varied thermal conditions (Figure S3).…”

“…Figure e depicts the deconvoluted spectra of O 1s, which can be fitted by three components at binding energies of 529.05, 530.43, and 530.68 eV. These component fittings can be assigned to the oxygenated species (Fe–O/CO/B–O), hydroxylated species (Fe–OH/C–OH/B–OH), and carbon-bonded species (C–O) respectively. , Furthermore, the resulting spectrum of Fe 2p deconvolution reveals two peaks for Fe 3+ (710.43 and 724.23 eV) along with two additional shake-up satellites at 718.8 and 732.2 eV and are in agreement with the reported literature. − …”

Low-temperature green synthesis of few-layered graphene sheets from pomegranate peels for supercapacitor applications

“…For the 2D band, three peaks are observed at ~ 2834.42, 3087.70 and 3199.02 . The splitting of the 2D band into these three peaks results due to the double-resonance Raman process which involves phonon-electron scattering 21 . Also, the observed 2D band at 2834.42 cm –1 is blue-shifted due to the strain and vibrational phonons related to impurities 32 .…”

“…Also, rice husk was combusted at 1123 K and chemically treated to obtain graphene sheets 20 . Furthermore, green tea-synthesized graphene sheets using a high-temperature pyrolysis technique have also been reported 21 . In all these works, graphene was obtained at elevated temperatures, and the synthesis process includes several steps, including chemical treatment.…”

Fabrication of ternary polyaniline‐titanium dioxide‐polypyrrole (PANI‐TiO2‐PPy) nanocomposite as an efficient polymer electrode for supercapacitors

“…In addition, synthesis methods play a very crucial role in improving the electrochemical performance of polymer nanocomposite based electrode materials. Most widely used synthesis methods for hybrid nanocomposite are in‐situ polymerization, 50 ex‐situ polymerization, 51 photo electrochemical route, 52 modified Hummers method, 53 template synthesis, 54 chemical precipitation, 55 sol–gel processing, 56 mechanical milling, 57 spray pyrolysis, 58 thermal evaporation, 59 hydrothermal method, 60 and combustion method 61 . Among these, in‐situ chemical oxidative polymerization is most extensively used route for preparation of polymer nanocomposite as the method allows uniform dispersion of metal oxide fillers in the polymer matrix, therefore providing strong interactions between the (TiO 2 ) filler and polymer (PANI‐PPy) matrix and resulting in a composite material with improved electrochemical properties 62 .…”