Polyaniline integration and interrogation on carbon nano-onions empowered supercapacitors

Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy

Nanocarbons are emerging at the forefront of nanoscience, with diverse carbon nanoforms emerging over the past two decades. Early cancer diagnosis and therapy, driven by advanced chemistry techniques, play a pivotal role in mitigating mortality rates associated with cancer. Nanocarbons, with an attractive combination of well-defined architectures, biocompatibility, and nanoscale dimension, offer an incredibly versatile platform for cancer imaging and therapy. This paper aims to review the underlying principles regarding the controllable synthesis, fluorescence origins, cellular toxicity, and surface functionalization routes of several classes of nanocarbons: carbon nanodots, nanodiamonds, carbon nanoonions, and carbon nanohorns. This review also highlights recent breakthroughs regarding the green synthesis of different nanocarbons from renewable sources. It also presents a comprehensive and unified overview of the latest cancer-related applications of nanocarbons and how they can be designed to interface with biological systems and work as cancer diagnostics and therapeutic tools. The commercial status for large-scale manufacturing of nanocarbons is also presented. Finally, it proposes future research opportunities aimed at engendering modifiable and high-performance nanocarbons for emerging applications across medical industries. This work is envisioned as a cornerstone to guide interdisciplinary teams in crafting fluorescent nanocarbons with tailored attributes that can revolutionize cancer diagnostics and therapy.

Strategic Way of Synthesizing Heteroatom-Doped Carbon Nano-onions Using Waste Chicken Fat Oil for Energy Storage Devices

An easy way of synthesizing low-cost carbon nanomaterials without the need for high-temperature processing approach is critical for energy storage applications because the demand has increased for affordable, long-term, and environmentally friendly synthesized carbon-based materials. Herein, we synthesized multilayered graphitic carbon nano-onions (CNOs) using an oil-wick flame pyrolysis approach, employing biowaste (chicken fat) oil as a cost-effective precursor. The prepared CNOs can provide enhanced ion movement and less resistance for electron transport by interconnecting CNO particles with one another. Furthermore, heteroatom (S,N)-doped CNOs (h-CNOs) were synthesized to optimize the hydrophilic and conductive properties of carbon materials, which eventually exalted the capacitive charge transfer kinetics. The h-CNOs demonstrated superior, highest specific capacitance of 261 F/g, while the undoped CNOs showed a capacitance of 180.6 F/g at a current density of 1 A/g. In addition to capacitance, the h-CNOs also demonstrated a rate capability of 69% and a good cycling stability of 97.5% under high current densities. An asymmetric supercapacitor was fabricated using the h-CNOs as the negative and MnCo2S4 (MCS) as the positive electrode. The device showed high energy and power performance of 32.8 Wh/kg and 7350 W/kg, respectively, with a capacitance retention of 97% over 5000 cycles. Considering the facile strategic way to produce novel carbonaceous materials derived from biowaste oil (chicken fat oil), this could be considered a potential advantage for commercial energy storage devices and may open the door to producing inexpensive, industrially revolutionizing energy storage devices.

Effect of Electrolyte Concentration on the Electrochemical Performance of Spray Deposited LiFePO4

LiFePO₄ is a common electrode cathode material that still needs some improvements regarding its electronic conductivity and the synthesis process in order to be easily scalable. In this work, a simple, multiple-pass deposition technique was utilized in which the spray-gun was moved across the substrate creating a "wet film", in which-after thermal annealing at very mild temperatures (i.e., 65 °C)-a LiFePO₄ cathode was formed on graphite. The growth of the LiFePO₄ layer was confirmed via X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. The layer was thick, consisting of agglomerated non-uniform flake-like particles with an average diameter of 1.5 to 3 μm. The cathode was tested in different LiOH concentrations of 0.5 M, 1 M, and 2 M, indicating an quasi-rectangular and nearly symmetric shape ascribed to non-faradaic charging processes, with the highest ion transfer for 2 M LiOH (i.e., 6.2 × 10^-9 cm²/cm). Nevertheless, the 1 M aqueous LiOH electrolyte presented both satisfactory ion storage and stability. In particular, the diffusion coefficient was estimated to be 5.46 × 10^-9 cm²/s, with 12 mAh/g and a 99% capacity retention rate after 100 cycles.

Semi-Polycrystalline Polyaniline-Activated Carbon Composite for Supercapacitor Application

We report on the synthesis of activated carbon-semi-polycrystalline polyaniline (SPani-AC) composite material using in-situ oxidative polymerization of aniline on the carbon surface in an aqueous HCl medium at an elevated temperature of 60 °C. The electroactive polymeric composite material exhibits a uniformly distributed spindle-shaped morphology in scanning electron microscopy (SEM) and well-defined crystallographic lattices in the high-resolution transmission electron microscopy (TEM) images. The X-ray diffraction (XRD) spectrum reveals sharp peaks characteristic of crystalline polyaniline. The characteristic chemical properties of polyaniline are recorded using laser Raman spectroscopy. The cyclic voltammetry curves exhibit features of surface-redox pseudocapacitance. The specific capacitance calculated for the material is 507 F g^-1 at the scan rate of 10 mV s^-1. The symmetrical two-electrodes device exhibits a specific capacitance of 45 F g^-1 at a current density of 5 A g^-1. The capacitive retention calculated was found to be 96% up to 4500 continuous charge-discharge cycles and observed to be gradually declining at the end of 10,000 cycles. On the other hand, Coulombic efficiency was observed to be retained up to 85% until 4500 continuous charge-discharge cycles which declines up to 72% at the end of 10,000 cycles. The article also presents a detailed description of material synthesis, the formation of polyaniline (Pani) chains, and the role of material architecture in the performance as surface redox supercapacitor electrode.

Semi-Polycrystalline–Polyaniline Empowered Electrochemical Capacitor

We report on the formation of semi-polycrystalline polyaniline, a novel electroactive polymeric material synthesized by a modified surfactant-free chemical route and its enhanced electrochemical capacitive behavior. The material exhibits uniformly arranged spindle-shaped morphology in scanning electron microscopy and well-defined crystallographic lattices in the high-resolution transmission electron microscopy images. The X-ray diffraction spectrum reveals sharp peaks characteristic of a crystalline material. The characteristic chemical properties of polyaniline are recorded using Fourier transform infrared technology and laser Raman spectroscopies. The cyclic voltammetry curves exhibit features of surface-redox pseudocapacitance. The specific capacitance calculated for the material is 551 F g−1 at a scan rate of 10 mV s−1. The cycle stability and the coulombic efficiency recorded at a current density of 12 A g−1 exhibited good stability (90.3% and 99.5%, respectively) over 3000 cycles.

Synergistically modified WS2@PANI binary nanocomposite-based all-solid-state symmetric supercapacitor with high energy density

WS2@PANI nanocomposite prepared by hydrothermal and physical blending method shows remarkably high specific capacitance and energy density while retaining excellent cyclic stability.