Supercapacitors also known as electrochemical capacitors, that store energy via either Faradaic or non-Faradaic processes, have recently grown popularity mainly because they complement, and can even replace, conventional energy storage systems in variety of applications. Supercapacitor performance can be improved significantly by developing new nanocomposite electrodes which utilizes both the energy storage processes simultaneously. Here we report, fabrication of the freestanding hybrid electrodes, by incorporating graphene and carbon nanotubes (CNT) in pyrrole monomer via its in-situ polymerization. At the scan rate of 5 mV s(-1), the specific capacitance of the polypyrrole-CNT-graphene (PCG) electrode film was 453 F g(-1) with ultrahigh energy and power density of 62.96 W h kg(-1) and 566.66 W kg(-1) respectively, as shown in the Ragone plot. A nanofibrous membrane was electrospun and effectively used as a separator in the supercapacitor. Four supercapacitors were assembled in series to demonstrate the device performance by lighting a 2.2 V LED.
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http://dx.doi.org/10.1038/srep14445 | DOI Listing |
Electromagn Biol Med
January 2025
Department of Mathematics, University of Gour Banga, Malda, India.
In cardiovascular research, electromagnetic fields generated by Riga plates are utilized to study or manipulate blood flow dynamics, which is particularly crucial in developing treatments for conditions such as arterial plaque deposition and understanding blood behavior under varied flow conditions. This research predicts the flow patterns of blood enhanced with gold and maghemite nanoparticles (gold-maghemite/blood) in an electromagnetic microchannel influenced by Riga plates with a temperature gradient that decays exponentially, under sudden changes in pressure gradient. The flow modeling includes key physical influences like radiation heat emission and Darcy drag forces in porous media, with the flow mathematically represented through unsteady partial differential equations solved using the Laplace transform (LT) method.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Environmental Engineering, Kwangwoon University, Seoul 01897, Republic of Korea.
The advancement of highly efficient and cost-effective electrocatalysts for electrochemical water splitting, along with the development of triboelectric nanogenerators (TENGs), is crucial for sustainable energy generation and harvesting. In this study, a novel hybrid composite by integrating graphitic carbon nitride (GCN) with an earth-abundant FeMg-layered double hydroxide (LDH) (GCN@FeMg-LDH) was synthesized by the hydrothermal approach. Under controlled conditions, with optimized concentrations of metal ions and GCN, the fabricated electrode, GCN@FeMg-LDH demonstrated remarkably low overpotentials of 0.
View Article and Find Full Text PDFHigh-speed silicon traveling-wave Mach-Zehnder modulators (MZMs) are key components to support optical fiber communication. However, one major challenge with all-silicon MZMs is to achieve efficient high-speed electro-optic (EO) modulation. The reported 3 dB bandwidth of silicon MZMs are generally below 70 GHz, with half-wave voltage ( ) around 5 V or larger, which can not support future 200 Gbaud data transmission.
View Article and Find Full Text PDFBioelectrochemistry
January 2025
School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China; Laboratory for Clinical Medicine, Capital Medical University, Beijing 100069, China. Electronic address:
A ratiometric electrochemical aptasensor was developed for ultra-sensitive detection of cortisol using aptamer (Apt) as recognition element, methylene blue (MB) as signal probe, and zirconium metal-organic framework (Zr-MOF) as carrier loaded with abundant MB for signal amplification. The carboxylated multi-walled carbon nanotubes (cMWCNTs)-modified Au electrode showed excellent electrochemical performance to immobilize complementary DNA (cDNA) for hybridizing with MB@Zr-MOF-Apt via amide bonds. In the presence of cortisol, it would compete with cDNA for binding the Apt, resulting in the detachment of MB@Zr-MOF-Apt complex from the electrode surface, and the electrochemical signal of MB was decreased, while that of [Fe(CN)] was basically unchanged.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
College of Chemistry and Chemical Engineering, Jishou University, Jishou, Hunan 416000, P. R. China.
Detecting β-lactoglobulin (β-Lg) with high sensitivity and selectivity is an urgent requirement due to nearly 80% of milk anaphylaxis, such as respiratory tract, skin urticaria, and gastrointestinal disorders, being caused by β-Lg. An ultrasensitive β-Lg electrochemical aptasensor utilizing core-satellite gold nanoparticle@silver nanocluster (AuNPs@AgNCs) nanohybrids as electrocatalysts was developed. First, β-Lg aptamer was anchored on gold electrodes and AuNPs to obtain high selectivity.
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