RESUMEN
Amid rising water contamination from industrial sources, tackling toxic dyes and pathogens is critical. Photocatalysis offers a cost-effective and eco-friendly solution to this pressing challenges. Herein, we synthesized Te4+ and Er3+ doped ZrO2 photocatalysts through hydrothermal method and investigated their efficacy in degrading Congo red (CR) and pathogens under visible light. XRD and Raman Spectroscopy confirm monoclinic and tetragonal mixed-phases without any impurities. Doping-induced defects, reduced crystalline diameter, high surface area, modified bandgap (2.95 eV), photoluminescence quenching, coupled with interfacial polarization, contribute to EZO's excellent dielectric response (1.149 × 106), for achieving remarkable photocatalytic activity, verified by photoelectrochemical measurements, LC-MS and phytotoxicity analysis. Under optimal conditions, EZO achieves 99% CR degradation within 100 min (TOC 79.9%), surpassing ZO (77%) and TZO (84%). Catalyst dosages, dye concentrations, and solution pH effect on EZO's photocatalytic performance are systematically assessed. Scavenging experiment emphasized the pivotal role of · OH in CR degradation with 96.4% efficiency after 4 cycles, affirming its remarkable stability. Moreover, EZO demonstrates ROS-mediated antibacterial activity against E. faecalis and E. coli bacteria under visible light, achieving >97% and >94% inhibition rate with an inhibition zone > 3 mm. Hence, the nanoparticle's dual action offers a practical solution for treating contaminated wastewater, ensuring safe irrigation.
Asunto(s)
Antibacterianos , Circonio , Antibacterianos/química , Antibacterianos/farmacología , Catálisis , Circonio/química , Nanopartículas/química , Erbio/química , Rojo Congo/químicaRESUMEN
Recently, titanium-based nanostructures with high nonlinear optical properties have found use in ultrafast photonic system applications. Here, we report a study of the third-order nonlinear optical property of the ${{\rm CuCo}_{0.5}}{{\rm Ti}_{0.5}}{{\rm O}_2}$CuCo0.5Ti0.5O2 (CCoTO) nanostructure synthesized via a simple chemical route. The 40-70 nm CCoTO nanoparticles with centrosymmetric crystalline structure show strong absorption in the 325-850 nm wavelength range due to the presence of different crystalline phases and surface vacancies. A Z-scan technique is used to study the electronic third-order nonlinearity of the synthesized nanoparticles, where a low-repetition-rate 120 fs laser source is employed to minimize thermal agitation-related nonlinearity. The CCoTO nanoparticles possess high surface defects due to oxygen- and copper-related vacancies, which are able to enhance the exciton oscillator strength resulting from the high value of third-order optical nonlinearity. The estimated values of nonlinear refractive index (${n_2}$n2) and nonlinear absorption coefficient ($\beta $ß) of the CCoTO are $ - {1.24}\; \times \;{{10}^{ - 15}}$-1.24×10-15 and ${3.79} \times {{10}^{ - 11}}$3.79×10-11, respectively, under ${188}\,\,{{\rm GW/cm}^2}$188GW/cm2 incident intensity. The intensity-dependent nonlinear optical property of the synthesized nanoparticles is also studied under different incident laser irradiation (62.7, 93, and ${188}\,\,{{\rm GW/cm}^2}$188GW/cm2). In the two-photon absorption (TPA)-dominated third-order nonlinear optical process, the values of ${n_2}$n2 and $\beta $ß of CCoTO are increased with intensifying the incident laser irradiation. The obtained high value of third-order optical nonlinearity of the synthesized nanostructure can be exploited in optical power limiters, pulse power reshaping, and optical switching applications.
RESUMEN
Because of the superior optical and electrical properties, copper-impregnated size tuneable high-temperature stable manganese dioxide semiconductor quantum dots (SQDs) have been successfully synthesized by a modified chemical synthesis technique. Their size-dependent dielectric properties, semiconducting properties, and current-voltage ( I- V) characteristics have been investigated. X-ray diffraction pattern and Raman spectra confirmed that the required phase is present. Because of the different sintering temperature tuneable size of SQDs has been found and confirmed by high-resolution transmission electron microscopy. The band gap energy of the material is found to be 1.25-1.67 eV, measured from Tauc plot using UV-vis absorbance spectrum and their semiconducting properties have been confirmed by the non linear current-voltage ( I- V) behavior. Most intense green emission peak of photoluminescence (PL) spectroscopy confirms the oxygen vacancy defect state. The stoke shifting of Raman spectra, UV absorption, and PL emission are the footprint of quantum confinement effect. Incorporation of a little amount of Cu in tetragonal hollandite structure of α-MnO2 generates strain within that structure. This leads to create sufficient crystal defect state as well as rise in dielectric constant accompanied with low dielectric loss and higher ac conductivity. All these highly desirable properties make the SQDs a potential candidate for developing multifunctional photo-electronic devices. Owing to the tuneable band gap and electronic transport of the SQDs, we realized that the controllable size paves the way for designing SQDs possessing unique properties for optical and electronic device applications. Using this material as a high dielectric separator, a high-performance supercapacitor has been successfully fabricated which can light up 15 light-emitting diodes for 47 min 23 s after charging them only for 30 s.
RESUMEN
BACKGROUND: We report the effects of nanoparticles in homeopathic preparations of copper salts on the electrical properties of polymer film. Previous work showed that the incorporation of metal-derived homeopathic medicines increases the dielectric constant and alternating current (AC) conductivity of an electroactive polymer film that is commonly used as a capacitor in the electronic industry.We report here the effect of dilution of one homeopathic medicine, Cuprum arsenicosum (CuAs), at 200C potency on the electrical properties of the polymer film of poly(vinylidene fluoride-co-hexafluoropropylene). METHODS: CuAs 200c was incorporated in the film by the solution casting method. The electrical characteristics were measured at different frequencies using an inductance, capacitance, and resistance meter. Fourier transform infrared spectroscopy (FTIR) was performed to detect phase change in the polymer film due to the incorporation of CuAs. Morphology and particle size were studied using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy. RESULTS: At 10 kHz frequency, both dielectric constant and AC conductivity increased approximately 18 times for the polymer film when incorporated with 2 mL CuAs at 200C potency. FTIR indicated the increase in conducting phase, while FESEM and EDX confirmed the presence of spherical CuAs particles. CONCLUSION: The incorporation of CuAs in the electroactive polymer film enhances the conductivity and dielectric constant. We conclude that these changes arise from the change in phase of the polymer film, and because of the presence of two different metals that affects the interfacial polarization.
Asunto(s)
Arsenitos/química , Cobre/química , Homeopatía , Hidróxidos/química , Nanopartículas/química , Técnicas de Dilución del Indicador , PolivinilosRESUMEN
The drawbacks inherent to traditional antibacterial therapies, coupled with the escalating prevalence of multi-drug resistant (MDR) microorganisms, have prompted the imperative need for novel antibacterial strategies. Accordingly, the emerging field of piezocatalysis in semiconductors harnesses mechanical stress to drive chemical reactions by utilizing piezo-generated free charge carriers, presenting a promising technology. To the best of our knowledge, this study is the first to provide a comprehensive overview of the eradication of pathogenic S. aureus bacteria using few-layer black phosphorus (SCBP) piezo catalyst under mechanical stimuli, along with the exploration of temperature dependent dielectric properties. The synthesis of the piezo catalysts involved a one-step cost-effective sonochemical method, and its structural, morphological, elemental, optical, and overall polarization properties were thoroughly characterized and compared with the traditional method-derived product (TABP). The synthesis-introduced defects, reduced crystalline diameters, modified bandgap (1.76 eV), nanoparticle aggregation, photoluminescence quenching, along with interfacial polarization, synergistically contribute to SCBP's exceptional dielectric response (4.596 × 107 @40 Hz), which in turn enhanced the piezocatalytic activity. When subjected to soft ultrasound stimulation at 15 kHz, the piezo catalyst SCBP demonstrated significant ROS-mediated antibacterial activity, resulting in a â¼94.7% mortality rate within 40 minutes. The impact of this study extends to cost-effective energy storage devices and advances in antibacterial therapy, opening new dimensions in both fields.