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1.
Int J Mol Sci ; 22(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34769039

RESUMO

We are reporting on the impact of air annealing temperatures on the physicochemical properties of electrochemically synthesized cadmium selenium telluride (CdSe0.6Te0.4) samples for their application in a photoelectrochemical (PEC) solar cell. The CdSe0.6Te0.4 samples were characterized with several sophisticated techniques to understand their characteristic properties. The XRD results presented the pure phase formation of the ternary CdSe0.6Te0.4 nanocompound with a hexagonal crystal structure, indicating that the annealing temperature influences the XRD peak intensity. The XPS study confirmed the existence of Cd, Se, and Te elements, indicating the formation of ternary CdSe0.6Te0.4 compounds. The FE-SEM results showed that the morphological engineering of the CdSe0.6Te0.4 samples can be achieved simply by changing the annealing temperatures from 300 to 400 °C with intervals of 50 °C. The efficiencies (ƞ) of the CdSe0.6Te0.4 photoelectrodes were found to be 2.0% for the non-annealed and 3.1, 3.6, and 2.5% for the annealed at 300, 350, and 400 °C, respectively. Most interestingly, the PEC cell analysis indicated that the annealing temperatures played an important role in boosting the performance of the photoelectrochemical properties of the solar cells.


Assuntos
Compostos de Cádmio/química , Compostos de Selênio/química , Telúrio/química , Sistema Solar , Temperatura
2.
J Mater Sci Mater Med ; 27(3): 57, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26787489

RESUMO

In this paper, the photocatalytic activity of Fe-TiO2 nanoparticles (NPs) under fluorescent light was studied using Escherichia coli and Staphylococcus aureus. Fe-TiO2 NPs were synthesized using a sol-gel method and characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-vis DRS) and transmission electron microscopy. The efficiency of photocatalytic inactivation towards E. coli was studied under different physicochemical parameters. The photocatalytic inactivation rate increased with increasing Fe content in TiO2 NPs and the highest inactivation was achieved for 3.0 mol% Fe-TiO2 NPs under fluorescent light. These results demonstrate that the presence of an optimum concentration of Fe in TiO2 matrix enhances the photocatalytic inactivation of TiO2 NPs under fluorescent light.


Assuntos
Escherichia coli/efeitos da radiação , Ferro/química , Luz , Nanopartículas Metálicas/química , Staphylococcus aureus/efeitos da radiação , Titânio/química , Aderência Bacteriana , Concentração de Íons de Hidrogênio , Processos Fotoquímicos , Espectroscopia Fotoeletrônica , Difração de Raios X
3.
Polymers (Basel) ; 14(3)2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-35160499

RESUMO

Today's world requires high-performance energy storage devices such as hybrid supercapacitors (HSc), which play an important role in the modern electronic market because supercapacitors (Sc) show better electrical properties for electronics devices. In the last few years, the scientific community has focused on the coupling of Sc and battery-type materials to improve energy and power density. Recently, various hybrid electrode materials have been reported in the literature; out of these, coordination polymers such as metal-organic frameworks (MOFs) are highly porous, stable, and widely explored for various applications. The poor conductivity of classical MOFs restricts their applications. The composite of MOFs with highly porous graphene (G), graphene oxide (GO), or reduced graphene oxide (rGO) nanomaterials is a promising strategy in the field of electrochemical applications. In this review, we have discussed the strategy, device structure, and function of the MOFs/G, MOFs/GO, and MOFs/rGO nanocomposites on Sc. The structural, morphological, and electrochemical performance of coordination polymers composites towards Sc application has been discussed. The reported results indicate the considerable improvement in the structural, surface morphological, and electrochemical performance of the Sc due to their positive synergistic effect. Finally, we focused on the recent development in preparation methods optimization, and the opportunities for MOFs/G based nanomaterials as electrode materials for energy storage applications have been discussed in detail.

4.
Sci Rep ; 12(1): 1998, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35132094

RESUMO

The Co3O4@N-MWCNT composite was synthesized by a sonication-supported thermal reduction process for supercapacitor applications. The structural and morphological properties of the materials were characterized via Raman, XRD, XPS, SEM-EDX, and FE-TEM analysis. The composite electrode was constructed into a three-electrode configuration and examined by using CV, GCD and EIS analysis. The demonstrated electrochemical value of ~ 225 F/g at 0.5 A/g by the electrode made it appropriate for potential use in supercapacitor applications.

5.
Nanomaterials (Basel) ; 11(2)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557051

RESUMO

Cellulose nanofiber (CNF) and hybrid zeolite imidazole framework (HZ) are an emerging biomaterial and a porous carbonous material, respectively. The composite of these two materials could have versatile physiochemical characteristics. A cellulose nanofiber and cobalt-containing zeolite framework-based composite was prepared using an in-situ and eco-friendly chemical method followed by pyrolysis. The composite was comprised of cobalt nanoparticles decorated on highly graphitized N-doped nanoporous carbons (NPC) wrapped with carbon nanotubes (CNTs) produced from the direct carbonization of HZ. By varying the ratio of CNF in the composite, we determined the optimal concentration and characterized the derived samples using sophisticated techniques. Scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS) confirmed the functionalization of CNF in the metallic cobalt-covered N-doped NPC wrapped with CNTs. The CNF-HZNPC composite electrodes show superior electrochemical performance, which is suitable for supercapacitor applications; its specific capacitance is 146 F/g at 1 A/g. Furthermore, the composite electrodes retain a cycling stability of about 90% over 2000 charge-discharge cycles at 10 A/g. The superior electrochemical properties of the cellulose make it a promising candidate for developing electrodes for energy storage applications.

6.
Colloids Surf B Biointerfaces ; 185: 110571, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683204

RESUMO

Cancer cells become resistant over the period to chemotherapeutic drugs and pose a challenging impediment for oncologists in providing effective treatment. Nanomedicine allows to overcome chemoresistance and is the focus of our investigation. Silica nanostructures have been highlighted as an interesting drug delivery platform in vitro and in vivo applications. Here we show the validity of nanomedicine approach for targeted chemotherapeutic cargo delivery to overcome chemoresistance in cancer cells both in vitro and in vivo. For demonstrating the concept, we functionalised ∼100 nm long porous silica nanoparticles (∼20 nm diameter ordered pore structure) by conjugating anticancer drug, cytochrome c enzyme and dual-function anticancer aptamer AS1411 in single supra-assembled nanocargos. The supra-assembly on the porous silica nanostructure allows for a high loading of catalytic enzyme cytochrome c, anticancer drug and aptamer. The silica supra-assembly is characterized by transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) surface area analysis. Conjugation of cargoes has been monitored at each step by UV-vis and Fluorescence spectroscopy. Finally, the constructed supra-assembled nanocarrier tested on chemoresistance colon cancer (HCT116) cells. A pH-responsive, intracellular theranostic cargo delivery has been achieved and the triple action of the nanocargo made an efficient killing of drug resistance colon cancer cells in vitro (∼ 92% cell death) through triplex therapy effects by supressing the P-glycoprotein (P-gp) level. Furthermore, in vivo animal toxicity studies demonstrated, the supra-assembled nanocargos have encouraging safety index to be used in cancer therapy and drug delivery applications.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Terapia de Alvo Molecular , Nanopartículas/química , Neoplasias/tratamento farmacológico , Dióxido de Silício/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Doxorrubicina/efeitos adversos , Doxorrubicina/farmacocinética , Doxorrubicina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/ultraestrutura , Neoplasias/patologia , Distribuição Tecidual/efeitos dos fármacos
7.
Polymers (Basel) ; 12(8)2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32727000

RESUMO

A binder-free process for the electrode preparation for supercapacitor application was suggested by drop casting graphene nanoplatelets on a carbon fiber (GnP@CF) followed by electrodeposition of Ni nanoparticles (NPs). The microstructure of the electrode showed that Ni was homogeneously distributed over the surface of the GnP@CF. XRD analysis confirmed the cubic structure of metallic Ni NPs. The Ni-GnP@CF electrode showed excellent pseudocapacitive behavior in alkaline solution by exhibiting a specific capacitance of 480 F/g at 1.0 A/g, while it was 375 F/g for Ni@CF. The low value of series resistance of Ni-GnP@CF (1 Ω) was attributed to the high capacitance. The enhanced capacitance of the electrode could be correlated to the highly nanoporous structure of the composite material, synergetic effect of the electrical double layer charge-storage properties of graphene, and the pseudocapacitive nature of Ni NPs.

8.
Sci Rep ; 9(1): 6034, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30988317

RESUMO

In this study, nickel hydroxide nanoparticles (NPs) decorated with nitrogen doped multiwalled carbon nanotubes (N-MWCNT) hybrid composite was synthesized by thermal reduction process in the presence of cetyl ammonium bromide (CTAB) and urea. The as-synthesized Ni(OH)2@N-MWCNT hybrid composite was characterized by FTIR, Raman, XRD, BET, BJH and FE-TEM analyses. These prepared porous carbon hybrid composite materials possessed high specific surface area and sheet like morphology useful for active electrode materials. The maximum specific capacitance of Ni(OH)2@N-MWCNT hybrid nanocomposite in the two electrode system showed 350 Fg-1 at 0.5 A/g,energy density ~43.75 Wkg-1 and corresponds to power density 1500 W kg-1 with excellent capacity retention after 5000 cycles. The results suggest that the prepared two-dimensional hybrid composite is a promising electrode material for electrochemical energy storage applications.

9.
J Mater Chem B ; 5(7): 1461-1470, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32264637

RESUMO

To achieve light-triggered drug release in cancer chemotherapy, we developed multimodal titanium dioxide (TiO2) nanocorals modified with methoxy polyethylene glycol (mPEG). TiO2 nanocoral-like structures were synthesized by optimizing a solvothermal method. The developed nanocoral structures were efficiently conjugated with chemotherapeutic drugs on the surfaces of the TiO2 nanoparticles. The mPEG on the surfaces of the multifunctional nanocorals effectively conjugated the drug and improved the biocompatibility of the nanocorals. Following UV light irradiation, the TiO2 nanocorals produce free radicals (˙OH and ˙O2 -) and are effective for drug release in cancer cells. Importantly, the amount of drug released from the multimodal TiO2 nanocorals can be regulated by UV-light irradiation time, which allows for further control of the anti-cancer effect. The multimodal TiO2 nanocorals exhibit a combination of light-activated, stimuli-triggered drug release for killing of cancer cell. The cytotoxicity, cellular uptake, and intracellular location of the formulations were evaluated in MCF7 cells. Our results showed that nanocoral-DOX complexes exhibited a greater cytotoxicity toward MCF7 cells than free DOX. Our work demonstrates that the therapeutic efficacy of DOX-loaded TiO2 nanocorals is strongly dependent on their loading mode and the chemotherapeutic effect is improved under UV light illumination, which provides a significant breakthrough for future applications of TiO2 as a light activated drug carrier in cancer chemotherapy.

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