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INTRODUCTION: Light is a key factor in moderating human alertness, both subjective and objective. However, the methodology applies in research on the effects of exposure to light of different wavelengths and intensities on objective and subjective alertness varies greatly and evidence on objective alertness in particular is still inconclusive. Thus, the present, highly standardized within-subject laboratory study on N = 44 healthy males explored how LED light of different intensities (dim vs. bright light) and wavelengths (red vs. blue) affected objective (reaction time/RT) as well as subjective (sleepiness) alertness in the morning after wake-up. METHODS: Participants spent two separate nights in the laboratory and were exposed to either one of the two light intensities or colors for 60 min after wake-up. Additionally, they indicated their sleepiness on the Karolinska Sleepiness Scale and participated in an auditory RT task before and after light intervention. It was hypothesized that both bright and blue light would lead to greater subjective and objective alertness when compared to dim and red light, respectively. RESULTS: Results indicated that average RTs were longer for participants in the bright light condition (p = 0.004, f2 = 0.07) and that RTs decreased post-light exposure irrespective of light being dim or bright (p = 0.026, f2 = 0.07). However, dim versus bright light and RT did not interact (p = 0.758, f2 = 0.07). Chronotype was a significant covariate in the interaction of dim versus bright light and subjective sleepiness (p = 0.008, f2 = 0.22). There was no difference in RTs when comparing exposure to red or blue light (p = 0.488, f2 = 0.01). Findings on subjective sleepiness and light of different wavelengths revealed that sleepiness was reduced after light exposure (p = 0.007, f2 = 0.06), although the wavelength of light did not appear to play a role in this effect (p = 0.817, f2 = 0.06). CONCLUSION: Hence, neither of the hypotheses could be confirmed. However, they indicated that evening types might benefit from exposure to bright light regarding sleepiness, but not morning types.
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In this study, porous polymers with nitrogen heterocyclic core structures are synthesized through the condensation of enaminonitrile and terephthalaldehyde monomers. These polymers are used as a platform to store bioactive nitric oxide (NO) and control its release. NO loading is achieved by nitrosating the polymers with acidified nitrite, a process that also imparts photoresponsivity to the polymers. Polymer composition and porosity affect NO storage and release. It is observed that under UV light at 365 nm in a PBS solution, the polymers (NO@DHP-POP) can release NO in a manner fully controlled by UV lighting. Under experimental conditions, these porous polymers release NO at a rate of ≈10.0-50.0 µmol g-1 over 60 min. These findings demonstrate the potential of these polymers for integrating NO delivery into phototherapy applications.
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Óxido Nítrico , Nitrogênio , Polímeros , Raios Ultravioleta , Óxido Nítrico/química , Porosidade , Polímeros/química , Polímeros/síntese química , Nitrogênio/química , Compostos Heterocíclicos/química , Estrutura Molecular , Propriedades de Superfície , Tamanho da PartículaRESUMO
This study developed a novel process named sulfidated zero-valent iron/peroxymonosulfate/visible light irradiation (S-mZVI/PMS/vis) for enhanced organic pollutant degradation. The S-mZVI/PMS/vis process exhibited remarkable catalytic activity, achieving a 99.6% rhodamine B (RhB) removal within 10 min. The degradation rate constant of RhB by the S-mZVI/PMS/vis process was found to be 6.49 and 79.84 times higher than that by the S-mZVI/PMS and PMS/vis processes, respectively. Furthermore, the S-mZVI/PMS/vis process worked efficiently across a wide pH range (3.0-9.0), and the result of five-cycle experiments demonstrated the excellent reusability and stability of S-mZVI. Radical quenching tests and electron paramagnetic resonance analysis indicated that ·O2-, 1O2, and h+ significantly contributed to the degradation of RhB through the S-mZVI/PMS/vis process. The visible light irradiation increased the Fe2+ concentration, improved the Fe3+/Fe2+ cycle, and consequently enhanced the PMS decomposition, reactive species production, and RhB degradation. This work offers a promising strategy to highly efficiently activate PMS for organic pollutants elimination from aqueous solutions.
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Ferro , Luz , Peróxidos , Rodaminas , Poluentes Químicos da Água , Ferro/química , Rodaminas/química , Poluentes Químicos da Água/química , Peróxidos/químicaRESUMO
Water pollution has caused problems in coastal areas, rivers, lakes, and other important water sources around the world as a result of inappropriate waste management. Meanwhile, these pollutants are harmful to humans and aquatic life. Textile dye effluent methyl orange (MO) was used in this work for dye degradation studies employing nanocomposites. As a result, the importance of synthesizing pure ZnO and Co3O4 nanoparticles with composites of ZnCo2O4 (zinc cobaltite) nanorods in three various proportions (90:10, 75:25, and 50:50) is emphasized in this study. Many advanced approaches were used to assess the various features of these materials, including size and shape. Fourier transform infrared (FT-IR) spectroscopy was used to determine the vibrational modes of the materials. The absorption measurements were then carried out using UV-vis spectroscopic techniques, and the photocatalytic breakdown of MO was done under visible light irradiation. The findings revealed that pure materials were inadequate for visible light activity, resulting in decreased degradation efficiencies. Spinel cobaltite structures have potential degradation efficiency under visible light, while ZnCo2O4 (50:50) catalyst has superior degradation efficiency of 59.8% over MO. The crystallite size, morphology, functional group, absorption wavelength, and band gap all play important roles in enhancing the material's photocatalytic activity under visible light. Meanwhile, ZnCo2O4 spinel structures are crucial for increasing charge carriers and reducing electron-hole recombination. As a result, zinc cobaltite minerals are widely used in industrial dye degradation applications.
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Compostos Azo , Nanotubos , Poluentes Químicos da Água , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Nanotubos/química , Compostos Azo/química , Cobalto/química , Espectroscopia de Infravermelho com Transformada de Fourier , Óxidos/química , Óxido de Zinco/químicaRESUMO
The present research utilizes a sol-gel approach to create a CoFe2O4/g-C3N4 nanocomposite (NC) and explored several analytical methods to evaluate physical, chemical and optical based characteristics via XRD, FTIR, UV-vis, SEM/EDS and XPS for the prepared pure CoFe2O4, g-C3N4, and CoFe2O4/g-C3N4 NC. The XRD results show that the prepared g-C3N4, CoFe2O4, exhibits hexagonal and cubic phases respectively, whereas the g-C3N4/CoFe2O4 NC exhibit mixing of two phases. The energy band gaps for pure g-C3N4, CoFe2O4 and g-C3N4/CoFe2O4 NC values are viz., 2.75, 1.3, and 2.4 eV. As photocatalysts, synthesized materials were utilized for the decomposition of Rhodamine-B (RhB) dye. Finally, the CoFe2O4/g-C3N4 NC showed good performance of photocatalysis for RhB dye disintegration under the stimulus of visible light. According to the induced visible light, the rate at which the photocatalytic degradation occurs for the CoFe2O4/g-C3N4 NC was found to be 57% in 120 min and this is greater when compared with pure catalysts like CoFe2O4 (28%) and g-C3N4 (10%). These outcomes suggest that the prepared NC have efficiently worked during the photocatalytic process compared with its pure materials.
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Cobalto , Compostos Férricos , Grafite , Rodaminas , Cobalto/química , Rodaminas/química , Compostos Férricos/química , Grafite/química , Compostos de Nitrogênio/química , Fotólise , Nanocompostos/química , Catálise , Nitrilas/químicaRESUMO
OBJECTIVE: To evaluate the efficacy and cytotoxicity of experimental 6% and 35% hydrogen peroxide gels (HP6 or HP35) incorporated with titanium dioxide nanoparticles (NP) co-doped with nitrogen and fluorine and irradiated with a violet LED light (LT). METHODS: Bovine enamel-dentin disks adapted to artificial pulp chambers were randomly assigned to bleaching (n = 8/group): NC (negative control), NP, HP6, HP6 + LT, HP6 + NP, HP6 + NP + LT, HP35, HP35 + LT, HP35 + NP, HP35 + NP + LT, and commercial HP35 (COM). Color (ΔE00) and whiteness index (ΔWID) changes were measured before and 14 days after bleaching. The extracts (culture medium + diffused gel components) collected after the first session were applied to odontoblast-like MDPC-23 cells, which were assessed concerning their viability, oxidative stress, and morphology. The amount of HP diffused through the disks was determined. Data were analyzed by generalized linear models or Kruskal Wallis Tests (α = 5%). RESULTS: HP6 + NP + LT exhibited ΔE00 and ΔWID higher than HP6 (p < 0.05) and similar to all HP35 groups. HP6 + NP + LT showed the lowest HP diffusion, and the highest cell viability (%) among bleached groups, preserving cell morphology and number of living cells similar to NC and NP. HP6 + LT, HP6 + NP, and HP6 + NP + LT exhibited the lowest cell oxidative stress among bleached groups (p < 0.05). HP35, HP35 + LT, and HP35 (COM) displayed the lowest cell viability. CONCLUSION: HP6 achieved significantly higher color and whiteness index changes when incorporated with nanoparticles and light-irradiated and caused lower cytotoxicity than HP35 gels. The nanoparticles significantly increased cell viability and reduced the hydrogen peroxide diffusion and oxidative stress, regardless of HP concentration. CLINICAL SIGNIFICANCE: Incorporation of co-doped titanium dioxide nanoparticles combined with violet irradiation within the HP6 gel could promote a higher perceivable and acceptable efficacy than HP6 alone, potentially reaching the optimal esthetic outcomes rendered by HP35. This approach also holds the promise of reducing cytotoxic damages and, consequently, tooth sensitivity.
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Sobrevivência Celular , Géis , Peróxido de Hidrogênio , Nanopartículas , Titânio , Clareadores Dentários , Clareamento Dental , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/toxicidade , Clareamento Dental/métodos , Titânio/química , Titânio/toxicidade , Animais , Bovinos , Clareadores Dentários/toxicidade , Clareadores Dentários/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Técnicas In Vitro , Odontoblastos/efeitos dos fármacos , Esmalte Dentário/efeitos dos fármacos , Distribuição Aleatória , Dentina/efeitos dos fármacosRESUMO
Many cell culture experiments are performed under light to evaluate the photodynamic or photosensitizing efficacy of various agents. In this study, the modulation of photosensitizing responses and phototoxicity under cell culture conditions by different medium components was investigated. The significant levels of reactive oxygen species (ROS) generated from DMEM, RPMI 1640, and MEM were observed under the irradiation of fluorescent light (FL) and white and blue LEDs, indicating that these media have their own photosensitizing properties; DMEM showed the most potent property. Phenol red-free DMEM (Pf-D) exhibited a stronger photosensitizing property than normal DMEM by 1.31 and 1.25 times under FL and blue LEDs, respectively; phenol red and riboflavin-free DMEM (PRbf-D) did not show any photosensitizing properties. The inhibitory effect on light transmission was more pronounced in DMEM than in RPMI, and the interference effect on green LED light was greatest at 57.8 and 27.4%, respectively; the effect disappeared in Pf-D. The media containing riboflavin induced strong phototoxicity in HaCaT keratinocytes by generating H2O2 under light irradiation, which was quenched by sodium pyruvate in the media. The presence of serum in the media was also reduced the phototoxicity; H2O2 levels in the media decreased serum content dependently. The phototoxicity of erythrosine B and protoporphyrin IX under FL was more sensitively pronounced in PRbf-D than in DMEM. The present results indicate that several medium components, including riboflavin, phenol red, sodium pyruvate, and serum, could modulate photosensitizing responses in a cell culture system by inducing photosensitizing activation and by interfering with irradiation efficacy and ROS generation.
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Meios de Cultura , Fármacos Fotossensibilizantes , Espécies Reativas de Oxigênio , Humanos , Meios de Cultura/química , Espécies Reativas de Oxigênio/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Riboflavina/farmacologia , Luz , Peróxido de Hidrogênio/farmacologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Queratinócitos/metabolismo , Técnicas de Cultura de Células/métodos , Linhagem CelularRESUMO
Photocatalytic technology has been recently conducted to remove microbial contamination due to its unique features of nontoxic by-products, low cost, negligible microbial resistance and broad-spectrum elimination capacity. Herein, a novel two dimensional (2D) g-C3N4/Bi(OH)3 (CNB) heterojunction was fabricated byincorporating Bi(OH)3 (BOH) nanoparticles with g-C3N4 (CN) nanosheets. This CNB heterojunction exhibited high photocatalytic antibacterial efficiency (99.3%) against Escherichia coli (E. coli) under visible light irradiation, which was 4.3 and 3.4 times that of BOH (23.0%) and CN (28.0%), respectively. The increase in specific surface area, ultra-thin layered structure, construction of a heterojunction and enhancement of visible light absorption were conducive to facilitating the separation and transfer of photoinduced charge carriers. Live/dead cell staining, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) assays and scanning electron microscopy (SEM) have been implemented to investigate the damage to the cell membrane and the leakage of the intracellular protein in the photocatalytic antibacterial process. The e-, h+ and O2â¢- were the active species involved in this process. This study proposed an appropriate photocatalyst for efficient treatment of bacterial contamination.
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Escherichia coli , Grafite , Escherichia coli/efeitos da radiação , Catálise , Grafite/química , Antibacterianos/farmacologia , Antibacterianos/química , LuzRESUMO
Doxorubicin (DOX) has been an effective antitumor agent for human liver cancer cells; however, an overdose might lead to major side effects appearing in clinical applications. In this work, we present a strategy of combining DOX and blue light (BL) irradiation for the antitumor treatment of HepG2 cells (one typical human liver cancer cell line). It is demonstrated that synergetic DOX and BL can significantly reduce cell proliferation and increase the apoptotic rate of HepG2 cells in comparison to individual DOX treatment. The additional BL irradiation is further helpful for enhancing the inhibition of cell migration and invasion. Analyses of reactive oxygen species (ROS) level and Western blotting reveal that the strategy results in more ROS accumulation, mitochondrial damage, and the upregulation of proapoptotic protein (Bcl-2) and downregulation of antiapoptotic protein (Bax). In addition to the improved therapeutic effect, the non-contact BL irradiation is greatly helpful for reducing the dosage of DOX, and subsequently reduces the side effects caused by the DOX drug. These findings offer a novel perspective for the therapeutic approach toward liver cancer with high efficiency and reduced side effects.
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Apoptose , Movimento Celular , Proliferação de Células , Doxorrubicina , Luz , Neoplasias Hepáticas , Espécies Reativas de Oxigênio , Doxorrubicina/farmacologia , Humanos , Células Hep G2 , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Movimento Celular/efeitos dos fármacos , Movimento Celular/efeitos da radiação , Luz AzulRESUMO
In this investigation, a multifunctional visible-light TX-based photosensitizer containing a siloxane moiety (TXS) was designed with a good overall yield of 54%. The addition of a siloxane moiety enabled the incorporation of a TX photosensitizer into a siloxane network by photoinduced sol-gel chemistry, thus avoiding its release. Both liquid 1H and solid-state 29Si NMR measurements undeniably confirmed the formation of photoacids resulting from the photolysis of the TXS/electron acceptor molecule (Iodonium salt), which promoted the photoinduced hydrolysis/condensation of the trimethoxysilane groups of TXS, with a high degree of condensation of its inorganic network. Notably, the laser flash photolysis, fluorescence, and electron paramagnetic resonance spin-trapping (EPR ST) experiments demonstrated that TXS could react with Iod through an electron transfer reaction through its excited states, leading to the formation of radical initiating species. Interestingly, the TXS/Iod was demonstrated to be an efficient photoinitiating system for free-radical (FRP) and cationic (CP) polymerization under LEDs@385, 405, and 455 nm. In particular, whatever the epoxy monomer mixtures used, remarkable final epoxy conversions were achieved up to 100% under air. In this latter case, we demonstrated that both the photoinduced sol-gel process (hydrolysis of trimethoxysilane groups) and the cationic photopolymerization occurred simultaneously.
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Zeolitic Imidazolate Framework-8 (ZIF-8) material was prepared by chemical precipitation method. The microstructure and physical properties of the as-prepared samples were characterized by XRD, BET, FESEM and UV spectrophotometer. The self-made four-channel measurement device was used to test the gas sensitivity of ZIF-8 material toward ethanol gas under photo-thermal synergistic excitation. The results showed that the sample was typical ZIF-8 (Eg = 4.96 eV) with a regular dodecahedron shape and the specific surface is up to 1793 m2/g. The as-prepared ZIF-8 has a gas response value of 55.04 to 100 ppm ethanol at 75°C and it shows good gas sensing selectivity and repeated stability. The excellent gas sensitivity can be attributed to the increase of free electron concentration in the ZIF-8 conduction band by photo-thermal synergistic excitation, and the large specific surface area of ZIF-8 material provides more active sites for gas-solid surface reaction. The reaction mechanism of ZIF-8 material under multi-field excitation was also discussed.
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Imidazóis , Zeolitas , Temperatura , Zeolitas/química , Temperatura BaixaRESUMO
Precious metals are valuable materials for the chemical industry, but they are scarce and pose a risk of supply disruption. Recycling precious metals from waste is a promising strategy, here we tactfully utilize light irradiation as an environmental-friendly and energy-saving adjunctive strategy to promote the reduction of precious metal ions, thereby improving the adsorption capacity and kinetics. A newly light-sensitive covalent organic framework (PP-COF) was synthesized to illustrate the effectiveness and feasibility of this light auxiliary strategy. The equilibrium adsorption capacities of PP-COF with light irradiation towards gold, platinum, and silver ions are 4729, 573, and 519 mg g-1, which are 3.3, 1.9, and 1.2 times the adsorption capacities under dark condition. Significantly, a filtration column with PP-COF can recover more than 99.8% of the gold ions in the simulated e-waste leachates with light irradiation, and 1 gram of PP-COF can recover gold from up to 0.15 tonne of e-waste leachates. Interestingly, the captured precious metals by PP-COF with light irradiation mainly exist in the micron-sized particles, which can be easily separated by extraction. We believe this work can contribute to precious metal recovery and circular economy for recycling resources.
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Green fabrication of superhydrophobic surface by water-based processing is still challenging, because introduction of the substances with hydrophilic moieties compromises its superhydrophobicity. Herein, a plasmon-driven photochemical reduction reaction under ultraviolet light (UVA) irradiation is first discovered and is applied to deoxygenation of hydrophilic organic adsorbates on rough nano-Ag coating for the formation of stable superhydrophobic surface. A nano-Ag coating with strong localized surface plasmon resonance in the UVA region is prepared by a water-based silver mirror reaction and results in a unique chemical reduction reaction on its surface. Consequently, the low residual hydrophilic functionalities and the formed cross-linked structure of the adsorbate on Ag nanoparticles (NPs) enables the coating to exhibit stable superhydrophobicity against to both air and water. The superhydrophobic Ag NP-coated sandpaper can also be used as a surface-enhanced Raman scattering (SERS) substrate to concentrate aqueous analytes for trace detection.
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A novel one-pot two-step multicomponent reaction has been achieved for the preparation of ß-CF3 enamines by using different aliphatic amines, propiolates, and CF3 SO2 Na as starting material. In this protocol, various aliphatic amines including primary amines, cyclic or acyclic secondary amines were demonstrated to be good coupling partners, and different ß-CF3 enamines were obtained in moderate to good yields. Among them, the primary aliphatic amines only gave pure (E)-ß-CF3 enamines as products. The synthetic utility of the MCRs strategy was further demonstrated by mild conditions, gram-scale synthesis and natural sunlight-induced protocol. Preliminary mechanistic studies suggest that this trifluoromethylation of C(sp2 )-H involves radical process.
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The development of industry and the increase in population have caused energy shortages and environmental pollution problems. Developing clean and storable new energy is identified as a key way to solve the problems above. Hydrogen is viewed as the most potential energy carrier due to its high calorific value and pollution-free. To convert solar energy into hydrogen energy, three nickel-based catalysts, Ni(aps)(pys)2 (aps=2-amino-2-phenylacetic salicylaldehyde) (1), Ni(ads)(pys)2 (ads=aniline salicylaldehyde, pys=pyridine-2-thiolate) (2), Ni(acs)(pys)2 (acs=aniline 5-chlorosalicylaldehyde) (3), were synthesized and explored as photocatalysts for hydrogen production. A three-component photocatalytic system for hydrogen production was constructed using target complex as photocatalyst, triethanolamine (TEOA) as electron sacrificial agent and fluorescein (FL) as photosensitizer. Under the optimum conditions, about 1504â µmol of H2 can be obtained with 25â mg catalyst 2 after 3â hours of irradiation. Finally, the hydrogen-production mechanism was discussed by experimental and theoretical methods.
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This study investigates the incorporation of active secondary amine moieties into the polymer backbone by co-polymerizing 2,4,6-tris(chloromethyl)-mesitylene with three diamines, namely 1,4-diaminobutane, m-phenylenediamine, and p-phenylenediamine. This process results in the stabilization of the amine moieties and the subsequently introduced nitroso groups. Charging bioactive nitric oxide (NO) into the polymers is accomplished by converting the amine moieties into N-nitroso groups. The ability of the polymers to store and release NO depends on their structures, particularly the amount of incorporated active secondary amines. With grafting photosensitive N-nitroso groups into the polymers, the derived NO@polymers exhibit photoresponsivity. NO release is completely regulated by adjusting UV light irradiation. These resulting polymeric NO donors demonstrate remarkable bactericidal and bacteriostatic activity, effectively eradicating E. coli bacteria and inhibiting their growth. The findings from this study hold promising implications for combining NO delivery with phototherapy in various medical applications.
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Óxido Nítrico , Raios Ultravioleta , Óxido Nítrico/química , Polímeros/farmacologia , Polímeros/química , Escherichia coli , Antibacterianos/farmacologia , AminasRESUMO
Nowadays, fast-growing industrialization has resulted in the release of enormous amounts of contaminants such as toxic dyes into water bodies and leading to cause health and environmental risks. In this regard, we prepared inorganic nanocomposites for the treatment of toxic dyes. Hence, we synthesized TiO2/PAni/GO nanocomposites and examined them by using XRD, SEM, TEM, UV-Vis spectroscopy, BET analysis, and a photoluminescence investigation. In addition, band gap energies of the nanocomposites were determined, and Total Organic Carbon (TOC) testing was used to determine dye degradation levels. The photocatalytic degradations of Thymol Blue and Rose Bengal dyes were investigated at different dye concentrations, illumination periods, solution pH values, and photocatalyst dosages. By using TiO2/PAni/GO, TiO2/PAni, and TiO2 at neutral pH, a photocatalyst dose of 1600 mg/L, and exposure to visible light, Thymol Blue and Rose Bengal were photodegraded 85-99%, 60-97%, and 10-20%, respectively, at a concentration of 25 ppm (180 min). Reductions in the TOCs confirmed their photodegradation, and a kinetic study revealed photodegradation followed first-order kinetics. This study shows the coating of polyaniline (PAni) and graphene oxide (GO) on TiO2 improved its ability to photodegrade Thymol Blue and Rose Bengal dye.
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Nanocompostos , Poluentes Químicos da Água , Fotólise , Corantes , Rosa Bengala , Poluentes Químicos da Água/análise , Nanocompostos/química , LuzRESUMO
The ubiquitous and refractory benzophenone (BP)-type ultraviolet filters, which are also endocrine disruptors, were commonly detected in the aquatic matrix and could not be efficiently removed by conventional wastewater treatment processes, thus causing extensive concern. Herein, a novel ternary nanocomposite, P-g-CN/α-Bi2O3/WO3 (P-gBW), was successfully fabricated by mixing cocalcinated components and applied to the decomposition of BP-type ultraviolet filters. The dual-Z-scheme heterostructure of P-gBW enhances visible-light absorption, efficiently facilitates separation and mobility, and prolongs the lifetime of photoinduced charge carriers via double charge transfer mechanisms. The optimum 95 wt% P-gBW exhibited excellent photocatalytic activity, degrading 96% 4-hydroxy benzophenone (4HBP) within 150 min and 93% 2,2',4,4'-tetrahydroxybenzophenone (BP-2) within 100 min under visible-light illumination, respectively. The pseudo-first-order rate constant of 4HBP (1.15 h-1) was 6.8-, 3.1-, 3.3- and 2.2-fold higher than those of WO3, P-g-CN, α-Bi2O3, and P-g-CN/α-Bi2O3, respectively, while that of BP-2 (1.71 h-1) was 5.2-, 2.2-, 3.2- and 1.5-fold higher, respectively. The improved photocatalytic degradation was attributed to efficient photoinduced charge carrier separation and migration and prevented the recombination of electron holes, as verified by photoluminescence, transient photocurrent response, and electrochemical impedance spectroscopy. Trapping experiments, electron paramagnetic resonance, and band energy position indicated an efficient dual-Z-scheme heterostructure.
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Benzofenonas , Luz , Iluminação , Espectroscopia de Ressonância de Spin EletrônicaRESUMO
Multidrug-resistant strains (MDRs) are becoming a major concern in a variety of settings, including water treatment and the medical industry. Well-dispersed catalysts such as BiPO4, ZnO nanoparticles (NPs), and different ratios of BiPO4/ZnO nanocomposites (NCs) were synthesized through hydrothermal treatments. The morphological behavior of the prepared catalysts was characterized using XRD, Raman spectra, PL, UV-Vis diffuse reflectance spectroscopy (UV-DRS), SEM, EDX, and Fe-SEM. MDRs were isolated and identified by the 16s rDNA technique as belonging to B. flexus, B. filamentosus, P. stutzeri, and A. baumannii. The antibacterial activity against MDRs and the photocatalytic methylene blue (MB) dye degradation activity of the synthesized NPs and NCs were studied. The results demonstrate that the prepared BiPO4/ZnO-NCs (B1Z4-75:300; NCs-4) caused a maximum growth inhibition of 20 mm against A. baumannii and a minimum growth inhibition of 12 mm against B. filamentosus at 80 µg mL-1 concentrations of the NPs and NCs. Thus, NCs-4 might be a suitable alternative to further explore and develop as an antibacterial agent. The obtained results statistically justified the data (p ≤ 0.05) via one-way analysis of variance (ANOVA). According to the results of the antibacterial and photocatalytic study, we selected the best bimetallic NCs-4 for the photoexcited antibacterial effect of MDRs, including Gram ve+ and Gram ve- strains, via UV light irradiation. The flower-like NCs-4 composites showed more effectiveness than those of BiPO4, ZnO, and other ratios of NCs. The results encourage the development of flower-like NCs-4 to enhance the photocatalytic antibacterial technique for water purification.
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Nanocompostos , Nanopartículas , Óxido de Zinco , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Nanocompostos/química , Raios Ultravioleta , Antibacterianos/farmacologia , Antibacterianos/químicaRESUMO
An unprecedented photocatalyst, Sm2EuSbO7, was successfully fabricated in this paper, through a high-temperature solid-state calcination method, which represented its first ever synthesis. Additionally, using the solvothermal method, the Sm2EuSbO7/ZnBiSbO5 heterojunction photocatalyst (SZHP) was fabricated, marking its debut in this study. XRD analysis confirmed that both Sm2EuSbO7 and ZnBiSbO5 exhibited pyrochlore-type crystal structures with a cubic lattice, belonging to the Fd3m space group. The crystal cell parameter was determined to be 10.5682 Å or 10.2943 Å for Sm2EuSbO7 or ZnBiSbO5, respectively. The band gap width measured for Sm2EuSbO7 or ZnBiSbO5 was 2.73 eV or 2.61 eV, respectively. Under visible light irradiation for 150 min (VLTI-150 min), SZHP exhibited remarkable photocatalytic activity, achieving 100% removal of parathion methyl (PM) concentration and 99.45% removal of total organic carbon (TOC) concentration. The kinetic constant (k) for PM degradation and visible light illumination treatment was determined to be 0.0206 min-1, with a similar constant k of 0.0202 min-1 observed for TOC degradation. Remarkably, SZHP exhibited superior PM removal rates compared with Sm2EuSbO7, ZnBiSbO5, or N-doped TiO2 photocatalyst, accompanied by removal rates 1.09 times, 1.20 times, or 2.38 times higher, respectively. Furthermore, the study investigated the oxidizing capability of free radicals through the use of trapping agents. The results showed that hydroxyl radicals had the strongest oxidative capability, followed by superoxide anions and holes. These findings provide a solid scientific foundation for future research and development of efficient heterojunction compound catalysts.