RESUMO
New advancements of photocatalytic activity with higher efficiency, low price are most important, which is challenging in industrialized and many fields. We have introduced CuNiO2 and CuNiO2/rGO nanocomposite was generally prepared by the hydrothermal treatment and tested to the photocatalytic studies. Photocatalytic measurements of CuNiO2 with different weight percentages CuNiO2/rGO (25/75), (50/50), and (75/25) are achieved to the efficiency under visible light, in this case, CuNiO2/rGO (50/50) composite have the highest performance is scrutinized. This was obeyed for a synergistic effect between CuNiO2 nanoparticles and rGO composites. Furthermore, the CuNiO2, CuNiO2/rGO (25/75), (50/50), and (75/25) nanocomposite were tested by several analyses like XRD, FT-IR, DRS UV Visible spectroscopy, Raman spectroscopy, and FESEM & HRTEM investigations. In this regard all measurements are very clear and satisfied; therefore we are encouraged for future developing environmental applications.
Assuntos
Azul de Metileno , Nanocompostos , Catálise , Grafite , Azul de Metileno/química , Nanocompostos/química , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
In this study, for the first time, red-emitting CsMgxPb1-xI3 quantum dots (QDs) are prepared by doping with magnesium (Mg) ions via the one-pot microwave pyrolysis technique. The X-ray diffraction and X-ray photoelectron spectroscopy results have confirmed partial substitution of Pb2+ by Mg2+ inside the CsPbI3 framework. The as-synthesized CsMgxPb1-xI3 QDs have exhibited excellent morphology, higher quantum yield (upto â¼89%), better photostability and storage stability than undoped CsPbI3. Next, the bioavailability of as-synthesized hydrophobic CsMgxPb1-xI3 QDs is improved by encapsulating them into gadolinium-conjugated pluronic 127 (PF127-Gd) micelles through hydrophobic interactions (PQD@Gd). The optical properties of perovskite quantum dots (PQDs) and the presence of Gd could endow the PQD@Gd with fluorescence imaging, magnetic resonance imaging (MRI), and phototherapeutic properties. Accordingly, the MRI contrasting effects of PQD@Gd nanoagents are demonstrated by employing T1 and T2 studies, which validated that PQD@Gd nanoagents had superior MR contrasting effect with a r2/r1 ratio of 1.38. In vitro MRI and fluorescence imaging analyses have shown that the PQD@Gd nanoagents are internalized into the cancer cells via a caveolae-mediated endocytosis pathway. The PQD@Gd nanoagents have exhibited excellent biocompatibility even at concentrations as high as 450 ppm. Interestingly, the as-prepared PQD@Gd nanoagents have efficiently produced cytotoxic reactive oxygen species in the cancer cells under 671 nm laser illumination and thereby induced cell death. Moreover, the PQD@Gd nanoagent also demonstrated excellent photocatalytic activity toward organic pollutants under visible light irradiation. The organic pollutants rhodamine b, methyl orange, and methylene blue were degraded by 92.11, 89.21, and 76.21%, respectively, under 60, 80, and 100 min, respectively, irradiation time. The plausible mechanism for the photocatalytic activity is also elucidated. Overall, this work proposes a novel strategy to enhance the optical properties, stability, and bioapplicability of PQDs. The multifunctional PQD@Gd nanoagents developed in this study could be the potential choice of components not only for cancer therapy due to dual-modal imaging and photodynamic therapeutic properties but also for organic pollutant or bacterial removal due to excellent photocatalytic properties.
Assuntos
Materiais Biocompatíveis/química , Imageamento por Ressonância Magnética , Imagem Óptica , Fotoquimioterapia , Pontos Quânticos/química , Catálise , Césio/química , Iodo/química , Chumbo/química , Magnésio/química , Teste de Materiais , Processos FotoquímicosRESUMO
α-NH4(VO2)(HPO4) nanosheets were developed by hydrothermal method. Furthermore, it's determined by the several analyses like XRD, Raman, FESEM, TEM, UV-Visible spectroscopy, TGA and DRS UV-Visible spectroscopy studies. The orthorhombic crystalline phase of α-NH4(VO2)(HPO4) nanosheets were recognized by XRD analysis. The α-NH4(VO2)(HPO4) nanosheets functional groups identification was investigated by Raman spectroscopy. Thermal gravimetric analysis of α-NH4(VO2)(HPO4) nanosheets were identified and its attain for three decomposition stages. The nanosheets of the α-NH4(VO2)(HPO4) was clearly evaluated by FESEM and TEM measurements. α-NH4(VO2)(HPO4) nanomaterial band gap energy was determined by DRS UV Visible spectroscopy analysis and the calculated bandgap energy is 1.83 eV. Hence, it was more convenient way for the dye degradation applications. These α-NH4(VO2)(HPO4) nanosheets was will be tested in the photocatalytic and antimicrobial applications. In this case, antimicrobial study was not encouraged in the catalyst. Consequently, this material has more encouraging for electrostatic interaction with enhanced for the applications.
Assuntos
Nanoestruturas , Catálise , Nanoestruturas/química , Análise Espectral RamanRESUMO
The poor stability and low catalytic activity of NH2-UiO-66 in basic solutions require the reactions to be conducted in acidic solutions, which seriously hinders its potential photocatalytic application. Herein, we report that NH2-UiO-66 coated with two-dimensional covalent organic frameworks (COFs) via imine bond connection presents not only high photocatalytic activity but also high stability and adaptability to the solution environment. The NH2-UiO-66/COF hybrid material was fabricated through the Schiff base reaction of NH2-UiO-66 with 4,4',4â³-(1,3,5-triazine-2,4,6-triyl)trianiline (TAPT) and 2,4,6-triformylphloroglucinol (TP). The hybrid material showed high stability in an alkaline environment, with only 4.7% of NH2-UiO-66 decomposed after the photocatalytic reaction. The optimum photocatalytic H2 evolution rate was 8.44 mmol·h-1·g-1 when triethanolamine was used as an electron-donating agent. The results presented here illustrate the possibility for effectively improving both the photocatalytic performance and stability of NH2-UiO-66 by coupling with COFs.
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A series of g-C3N4-SnO2/TiO2 nanotubes/Ti plates were fabricated via simple dipping of TiO2 nanotubes/Ti in a solution containing SnCl2 and g-C3N4 nanosheets and finally annealing of the plates. Synthesized plates were characterized by various techniques. The SEM analysis revealed that the g-C3N4-SnO2 nanosheets with high physical stability have been successfully deposited onto the surface of TiO2 nanotubes/Ti plate. Photocatalytic activity was investigated using two probe chemical reactions: oxidative decomposition of acetic acid and oxidation of 2-propanol under irradiation. Antibacterial activities for Escherichia coli (E. coli) bacteria were also investigated in dark and under UV/Vis illuminations. Detailed characterization and results of photocatalytic and antibacterial activity tests revealed that semiconductor coupling significantly affected the photocatalyst properties synthesized and hence their photocatalytic and antibacterial activities. Modification of TiO2 nanotubes/Ti plates with g-C3N4-SnO2 deposits resulted in enhanced photocatalytic activities in both chemical and microbial systems. The g-C3N4-SnO2/TiO2 nanotubes/Ti plate exhibited the highest photocatalytic and antibacterial activity, probably due to the heterojunction between g-C3N4-SnO2 and TiO2 nanotubes/Ti in the ternary composite plate and thus lower electron/hole recombination rate. Based on the obtained results, a photocatalytic and an antibacterial mechanism for the degradation of E. coli bacteria and chemical pollutants over g-C3N4-SnO2/TiO2 nanotubes/Ti plate were proposed and discussed.