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1.
Chemosphere ; 344: 140325, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37797896

RESUMO

In this work, g-C3N5/CdS dendrite/AgNPs nanocomposite was synthesized using a mixed method consisting of hydrothermal, ultrasonic and chemistry reduction with sodium borohydride. The characterization of the as-prepared nanocomposite was done using infrared spectroscopy, X-ray, scanning electron microscopy, transmission electron microscopy, BET, and DRS methods was performed. The DRS results showed that the g-C3N5/CdS dendrite/AgNPs nanocomposite nanocomposite has a band gap of 1.08 eV. This band gap indicates the good capability of this nanocomposite as a photocatalyst. Accordingly, the photocatalytic degradation of chlorpyrifos (CPS) in was performed in an aqueous solution of the synthesized nanocomposite. The results showed that almost 95.3% of this poison, a concentration of 50 mg L-1 was degraded in the presence of 0.05 g L-1 of nanocomposite at pH = 5 in a 60 min. Hydroxide radicals and holes play a significant role in the photocatalytic process. The reusability of the nanocomposite with excellent performance in the degradation of photocatalytic toxins caused by the reduction in the electron-hole recombination and the high surface area of the nanocomposite are among the unique features of this work.


Assuntos
Clorpirifos , Nanopartículas Metálicas , Nanocompostos , Prata/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Catálise , Nanocompostos/química
2.
Sci Rep ; 13(1): 16221, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37758758

RESUMO

Due to the importance of energy storage systems based on supercapacitors, various studies have been conducted. In this research CuO, NCNO and the flower like CuO/NCNO have been studied as a novel materials in this field. The resulte showed that the synthesized CuO nanostructutes have flower like morphology which studied by FE-SEM analisis. Further, the XRD pattern confirmed the crystalline properties of the CuO/NCNO nanocomposite, and the Raman verified the functional groups and vibrations of the components of CuO/NCNO nanocomposite. In a two-electrode system at a current density of 4 A/g, the capacitance, power density, and energy density were 450 F/g, 3200 W/kg, and 98 Wh/kg, respectively. The charge transfer resistances of CuO and NCNO/CuO electrodes obtained 8 and 2 Ω respectively, which show that the conductivity and supercapacitive properties of nanocomposite are better than pure components. Also, the stability and low charge transfer resistance are other advantages obtained in a two-symmetrical electrode investigation. The stability investigation showed that after 3000 consecutive cycles, only 4% of the initial capacitance of the CuO/NCNO electrode decreased.

3.
Int J Biol Macromol ; 242(Pt 1): 124585, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37105252

RESUMO

Global waste production is anticipated reach to 2.59 billion tons in 2030, thus accentuating issues of environmental pollution and health security. 37 % of waste is landfilled, 33 % is discharged or burned in open areas, and only 13.5 % is recycled, which makes waste management poorly efficient in the context of the circular economy. There is, therefore, a need for methods to recycle waste into valuable materials through the resource recovery process. Progress in the field of recycling is strongly dependent on the development of efficient, stable, and reusable yet inexpensive catalysts. In this case, growing attention has been paid to the development and application of nanobiocatalysts with promising features. The main purpose of this review paper is to: (i) introduce nanobiomaterials and describe their effective role in the preparation of functional nanobiocatalysts for the recourse recovery aims; (ii) provide production methods and the efficiency improvement of nanobaiocatalysts; (iii) give a comprehensive description of valued resource recovery for reducing toxic chemicals from the contaminated environment; (iv) describe various technologies for the valued resource recovery; (v) state the limitation of the valued resource recovery; (vi) and finally economic importance and current scenario of nanobiocatalysts strategies applicable for the resource recovery processes.


Assuntos
Gerenciamento de Resíduos , Águas Residuárias , Amônia , Poluição Ambiental , Polissacarídeos , Reciclagem
4.
Chemosphere ; 267: 129293, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33348263

RESUMO

Appearance of antibiotic resistance in bacteria is a convoluted topic, particularly in treating pestiferous immunodeficiency correlated diseases. The main objective of the current research is to fabricate antibacterial pads by utilizing of graphene quantum dots (GQDs) as a linker, stabilizing, and reduction agent of in situ synthesized Ag nanoparticles (Ag NPs) on cotton pad. Five different antibacterial pads including cotton/Ag pad, cotton/GQDs/Ag pad, cotton/Ag/GQDs pad, cotton/GQDs/Ag/GQDs pad, and cotton/Ag/GQDs/Ag were fabricated and their antibacterial activities were compared to those of as-synthesized Ag/GQDs nanocomposites. The results indicate that cotton/GQDs/Ag pad shows a very promising minimum inhibitory concentration(MIC) of 0.09 and 0.01 against S. aureus and E. coli, respectively. Using GQDs as a linker (cotton/GQDs/Ag) and as a stabilizing agent (cotton/Ag/GQDs) significantly improves the antibacterial activity of Ag NPs.


Assuntos
Grafite , Nanopartículas Metálicas , Nanocompostos , Pontos Quânticos , Antibacterianos/farmacologia , Escherichia coli , Prata , Staphylococcus aureus
5.
Mater Sci Eng C Mater Biol Appl ; 99: 296-303, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889703

RESUMO

TiO2/Sb2S3/GQDs nanocomposite was prepared by solvothermal method to study its antibacterial properties. XRD, SEM, EDX, FT-IR and TEM were used to characterize prepared nanomaterials. To evaluate effect of graphene quantum dots (GQD) on the antibacterial activity of final products, antibacterial activity of TiO2, TiO2/GQDs, Sb2S3, Sb2S3/GQDs were compared with TiO2/Sb2S3/GQDs. TiO2/Sb2S3/GQDs shows the highest antibacterial activity against E. coli and Staphylococcus aureus. TiO2/Sb2S3/GQDs show the lowest measure the minimal inhibitory concentration against E. coli and Staphylococcus aureus. MIC for E. coli and Staphylococcus aureus are 0.03 and 0.1, respectively.


Assuntos
Antibacterianos/farmacologia , Antimônio/química , Escherichia coli/efeitos dos fármacos , Química Verde/métodos , Nanocompostos/química , Pontos Quânticos/química , Staphylococcus aureus/efeitos dos fármacos , Sulfetos/química , Titânio/química , Grafite/química , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
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