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1.
Nanomaterials (Basel) ; 14(11)2024 May 28.
Article in English | MEDLINE | ID: mdl-38869571

ABSTRACT

Due to their unique physical and chemical properties, complex nanostructures based on carbon nanotubes and transition metal oxides are considered promising electrode materials for the fabrication of high-performance supercapacitors with a fast charge rate, high power density, and long cycle life. The crucial role in determining their efficiency is played by the properties of the interface in such nanostructures, among them, the type of chemical bonds between their components. The complementary theoretical and experimental methods, including dispersion-corrected density functional theory (DFT-D3) within GGA-PBE approximation, scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman, X-ray photoelectron, and X-ray absorption spectroscopies, were applied in the present work for the comprehensive investigation of surface morphology, structure, and electronic properties in CuOx/MWCNTs and NiOx/MWCNTs. As a result, the type of interfacial interaction and its correlation with electrochemical characteristics were determined. It was found that the presence of both Ni-O-C and Ni-C bonds can increase the contact between NiO and MWCNTs, and, through this, promote electron transfer between NiO and MWCNTs. For NiOx/MWCNTs, better electrochemical characteristics were observed than for CuOx/MWCNTs, in which the interfacial interaction is determined only by bonding through Cu-O-C bonds. The electrochemical properties of CuOx/MWCNTs and NiOx/MWCNTs were studied to demonstrate the effect of interfacial interaction on their efficiency as electrode materials for supercapacitor applications.

2.
ChemSusChem ; 17(5): e202301367, 2024 Mar 08.
Article in English | MEDLINE | ID: mdl-37948061

ABSTRACT

Supercapacitors (SCs) have emerged as critical components in applications ranging from transport to wearable electronics due to their rapid charge-discharge cycles, high power density, and reliability. This review offers an analysis of recent strides in supercapacitor research, emphasizing pivotal developments in sustainability, electrode materials, electrolytes, and 'smart SCs' designed for modern microelectronics with attributes such as flexibility, stretchability, and biocompatibility. Central to this discourse are two dominant electrode materials: carbon materials (CMs), primarily in electric double layer capacitors (EDLCs), and pseudocapacitive materials, involving oxides/hydroxides, chalcogenides, metal-organic frameworks, conductive polymers and metal nitrides such as MXene. Despite EDLCs' historical use, challenges such as low energy density persist, with heteroatom introduction into the carbon lattice seen as a solution. Concurrently, pseudocapacitive materials dominate recent studies, with efficiency enhancement strategies, such as the creation of hybrids based on different types of materials, surface structural engineering and doping, under exploration. Electrolyte innovation, especially the shift towards gel polymer electrolytes for flexible SCs, and the harmonization of electrode materials with SC designs are highlighted. Emphasis is given to smart SCs with novel attributes such as self-charging, self-healing, biocompatibility, and environmentally conscious designs. In summary, the article underscores the drive in sustainable supercapacitor research to achieve high energy and power density, steering towards SCs that are efficient and versatile and involving bioderived/biocompatible SC materials. This brief review is based on selected recent references, offering depth combined with an accessible overview of the SC landscape.

3.
ChemSusChem ; 16(8): e202202065, 2023 Apr 21.
Article in English | MEDLINE | ID: mdl-36651314

ABSTRACT

Sustainable human development urgently calls for decreasing the cost of energy storage. Continuous massive consumption of dedicated carbon electrode materials with complex internal molecular architectures requires rethinking both the source of materials and the process of their production. Finding an efficient sustainable solution is focused on the reuse and development of waste processing into corresponding high-value-added carbon materials. The processing of solid wastes into solid value-added carbon materials ("solid-to-solid") is relatively well developed but can be a two-stage process involving carbon architecture rearrangement and heteroatom doping. Processing liquid wastes into high-value-added solid material ("liquid-to-solid") is typically much more challenging with the need for different production equipment. In the present study, a new approach is developed to bypass the difficulty in the "liquid-to-solid" conversion and simultaneously built in the ability for heteroatom doping within one production stage. Polycondensation of liquid humins waste with melamine (as a nitrogen-containing cross-linking component) results in solidification with preferential C and N atomic arrangements. For subsequent thermochemical conversion of the obtained solidified wastes, complicated equipment is no longer required, and under simple process conditions, carbon materials for energy storage with superior characteristics were obtained. A complete sequence is reported in the present study, including liquid waste processing, nitrogen incorporation, carbon material production, structural study of the obtained materials, detailed electrochemical evaluation and real supercapacitor device manufacture and testing.

4.
Urol Ann ; 13(2): 194-197, 2021.
Article in English | MEDLINE | ID: mdl-34194152

ABSTRACT

Extrauterine leiomyoma is a rare benign tumor, originating from smooth muscle cells, most often localized in the uterus. Extrauterine localization of leiomyoma is extremely rare. The presence of a neoplasm near the urethra always poses a challenge for differential diagnosis. Variety of pathologies sharing similar clinical findings requires further diagnostic testing and doctor alertness. We present the clinical case of urethral leiomyoma in a female patient aged 42 years complaining of frequent urination and vulval mass. The patient underwent neoplasm removal with further histologic examination revealing urethral leiomyoma. The article features the diagnosis and treatment of this rare pathology.

5.
Res Rep Urol ; 13: 335-340, 2021.
Article in English | MEDLINE | ID: mdl-34113581

ABSTRACT

Cystic formations in the prostate are quite common, but the vast majority are benign. The cystic form of prostate adenocarcinoma can present unexpected symptoms, and management can be difficult because of the local advanced stage of the disease. A unique feature of this case is the surgical local cancer treatment. In this clinical case, we describe the literature surrounding this rare form of neoplasm. We present a clinical case of a rare form of prostate cancer in a 71-year-old male who was admitted to ER with acute urinary retention. A huge obstructing prostatic cyst was revealed. After successful trial-without-catheter, the patient underwent transperineal cyst draining and this restored urination. PSAt was increased up to 55 ng/mL. The cystic wall biopsy revealed adenocarcinoma with a Gleason score of 8 (4+4) (Gleason Group IV), and distant metastasis was noticed with PSMA PET/CT. The patient started androgen deprivation therapy (ADT) with excellent PSA dynamics in three months. Because of lower urinary tract symptoms, he needed local treatment and underwent radical prostatectomy. A three-month follow-up demonstrated a common post-operative period, mild stress incontinence, and PSAt 0.004 ng/mL. Cystic prostatic carcinoma can manifest as urinary retention and be mistakenly taken for a benign obstructing prostate cyst. Despite the locally advanced tumor, it can be successfully treated locally in highly selected patients.

6.
Nanomaterials (Basel) ; 11(1)2021 Jan 13.
Article in English | MEDLINE | ID: mdl-33450986

ABSTRACT

A series of NiO/C nanocomposites with NiO concentrations ranging from 10 to 90 wt% was synthesized using a simple and efficient two-step method based on non-isothermal decomposition of Nickel(II) bis(acetylacetonate). X-ray diffraction (XRD) measurements of these NiO/C nanocomposites demonstrate the presence of ß-NiO. NiO/C nanocomposites are composed of spherical particles distributed over the carbon support surface. The average diameter of nickel oxide spheres increases with the NiO content and are estimated as 36, 50 and 205 nm for nanocomposites with 10, 50 and 80 wt% NiO concentrations, respectively. In turn, each NiO sphere contains several nickel oxide nanoparticles, whose average sizes are 7-8 nm. According to the tests performed using a three-electrode cell, specific capacitance (SC) of NiO/C nanocomposites increases from 200 to 400 F/g as the NiO content achieves a maximum of 60 wt% concentration, after which the SC decreases. The study of the NiO/C composite showing the highest SC in three- and two-electrode cells reveals that its SC remains almost unchanged while increasing the current density, and the sample demonstrates excellent cycling stability properties. Finally, NiO/C (60% NiO) composites are shown to be promising materials for charging quartz clocks with a power rating of 1.5 V (30 min).

7.
Chemistry ; 27(10): 3382-3396, 2021 Feb 15.
Article in English | MEDLINE | ID: mdl-33119938

ABSTRACT

Development of sustainable bio-based materials for removal of toxic contaminants from water is a high priority goal. Novel bio-based binary and ternary copolymers with enhanced ion-exchange, adsorption and antibacterial properties were obtained by using plant biomass-derived diallyl esters of furandicarboxylic acid (FDCA) as crosslinking agents and easily available vinyl monomers. The synthesized copolymer materials showed higher sorption capacities for NiII , CoII and CuII compared to the commercial ion-exchange resins, and they maintained their high metal adsorption capacities for over 10 cycles of regeneration. The synthesized copolymer gels containing 1-5 wt % of the crosslinker showed excellent water absorption capacities. The synthesized copolymers with 1 % crosslinker content showed swelling ratios high enough to also act as moisture absorbents. Synthesized copolymers with crosslinker content of 10 wt % performed as contact-active antibacterials by inhibiting the growth of Gram-positive (S. aureus) and Gram-negative bacteria (E. coli, K. pneumonia) in suspension tests.


Subject(s)
Water/parasitology , Adsorption , Escherichia coli , Hydrogen-Ion Concentration , Metals , Staphylococcus aureus , Water Pollutants, Chemical
8.
ChemSusChem ; 11(20): 3599-3608, 2018 Oct 24.
Article in English | MEDLINE | ID: mdl-30168655

ABSTRACT

Biomass processing wastes (humins) are anticipated to become a large-tonnage solid waste in the near future, owing to the accelerated development of renewable technologies based on utilization of carbohydrates. In this work, the utility of humins as a feedstock for the production of activated carbon by various methods (pyrolysis, physical and chemical activation, or combined approaches) was evaluated. The obtained activated carbons were tested as potential electrode materials for supercapacitor applications and demonstrated combined micro- and mesoporous structures with a good capacitance of 370 F g-1 (at a current density of 0.5 A g-1 ) and good cycling stability with a capacitance retention of 92 % after 10 000 charge/discharge cycles (at 10 A g-1 in 6 m aqueous KOH electrolyte). The applicability of the developed activated carbon for practical usage as a supercapacitor electrode material was demonstrated by its successful utilization in symmetric two-electrode cells and by powering electric devices. These findings provide a new approach to deal with the problem of sustainable wastes utilization and to advance challenging energy storage applications.

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