Co-doped Zinc Oxide Nanoparticles Research Articles

Fabrication, characterization and application of W/N co-doped zinc oxide nanoparticles as a promising photoanode for dye-sensitized solar cells

In the present investigation, undoped, W doped, and W/N co-doped ZnO nanoparticles were prepared by sol–gel route. Here, the ZnO layers were fabricated via the doctor blade method. Hexagonal wurtzite structure is determined by XRD studies. The formation of a hexagonal wurtzite structure was observed from X-ray powder diffraction (XRD) resulting in a slight increase in crystallite size with an increase in doping content. The UV observation shows that W/N co-doping shifted the absorption spectra towards a higher wavelength and reduces the band gap energy. The EDS spectra confirms the high purity and triumphant doping of the W(tungsten) and N(nitrogen) into the ZnO lattice. The morphology of undoped and W/N co-doped ZnO nanoparticles was demonstrated by using FESEM and HRTEM. The 2 % W and 1.5 % N co-doped ZnO photoanode based DSSC (dye-sensitized solar cells) gained the highest short circuit current density of 8.44 mAcm−2 having an open-circuit voltage of 0.65 V, and PCE (power conversion efficiency) of 3.60 %.

Psidium guajava-mediated green synthesis of Fe-doped ZnO and Co-doped ZnO nanoparticles: a comprehensive study on characterization and biological applications.

The efficacy of nanoparticles (NPs) in healthcare applications hinges on their biocidal activity and biocompatibility. This research is dedicated to green-synthesized NPs with potent biocidal properties, aiming for high inhibition rates in bacterial infections and offering a multifunctional application, including potential use in anticancer therapy, in comparison to traditional antibiotics. The present study focuses on synthesis of zinc oxide (ZnO) nanoparticles (NPs), including iron-doped ZnO (GZF) and cobalt-doped ZnO (GZC), using the green co-precipitation method involving Psidium guajava (P. guajava) leaf extract. The physicochemical properties of the synthesized NPs were analyzed using various characterization techniques. The antibacterial and anticancer activity depends on the generation of reactive oxygen species (ROS), particle size, surface area, oxygen vacancy, Zn2+ release, and diffusion ability. The antibacterial activity of the synthesized NPs was tested against various Gram-positive (Streptococcus pneumoniae (S. pneumoniae), Bacillus subtilis (B. subtilis) and Gram-negative (Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) bacterial strains. The zone of inhibition showed higher activity of GZC (18-20mm) compared to GZF (16-19mm) and GZO (11-15mm) NPs. Moreover, anticancer studies against blood cancer cell line (MOLT-4) showed half-maximal inhibitory concentration of 11.3μg/mL for GZC compared to GZF and GZO NPs with 12.1μg/mL and 12.5μg/mL, respectively. Cytotoxicity assessments carried out on the fibroblast L929 cell line indicated that GZO, GZF, and GZC NPs demonstrated cell viabilities of 85.43%, 86.66%, and 88.14%, respectively. Thus, green-synthesized GZC NPs hold promise as multifunctional agents in the biomedical sector.

Photocatalytic evaluation of disperse purple dye using Polyvinylpyrrolidone capped bare and Cu+2/Fe+3 codoped ZnO nano catalysts

Polyvinylpyrrolidone capped bare zinc oxide and codoped with cupric and ferric ions, have been fabricated by a facile polyol reduction method with ethylene glycol. The as-fabricated nanoparticles were calcinated to control their size and morphology. The fabricated nanoparticles were characterized using various techniques including X-ray diffraction, scanning electron microscopy, energy dispersion X-rays, UV–Vis spectroscopy, and Fourier transform infrared Spectroscopy. The results showed phase pure nanoparticles with wurtzite zinc oxide structure, and a blue shift in absorbance spectrum when zinc oxide was codoped with cupric and ferric ions.The study examined the degradation rate of disperse purple dye using bare and codoped zinc oxide nanoparticles in the solar region. Codoped nanocatalysts showed superior efficiency compared to bare zinc oxide. The kinetic analysis of the dye was conducted, revealing that the degradation of the dye followed a pseudo-first-order kinetics pattern. Furthermore, about 99 % degradation of the dye solution in 110 min by codoped zinc oxide as compared to bare zinc oxide (84 %) under solar light suggests Cu+2/Fe+3 codoped zinc oxide is an emerging tool for environmental remediation.

Optimization of physical and dielectric properties of Co-doped ZnO nanoparticles for low-frequency devices.

In this study, zinc-oxide (ZnO) nanoparticles (NPs) doped with cobalt (Co) were synthesized using a simple coprecipitation technique. The concentration of Co was varied to investigate its effect on the structural, morphological, optical, and dielectric properties of the NPs. X-ray diffraction (XRD) analysis confirmed the hexagonal wurtzite structure of both undoped and Co-doped ZnO-NPs. Scanning electron microscopy (SEM) was used to examine the morphology of the synthesized NPs, while energy-dispersive X-ray spectroscopy (EDX) was used to verify their purity. The band gap of the NPs was evaluated using UV-visible spectroscopy, which revealed a decrease in the energy gap as the concentration of Co2+ increased in the ZnO matrix. The dielectric constants and AC conductivity of the NPs were measured using an LCR meter. The dielectric constant of the Co-doped ZnO-NPs continuously increased from 4.0 × 10-9 to 2.25 × 10-8, while the dielectric loss decreased from 4.0 × 10-8 to 1.7 × 10-7 as the Co content increased from 0.01 to 0.07%. The a.c. conductivity also increased with increasing applied frequency. The findings suggest that the synthesized Co-doped ZnO-NPs possess enhanced dielectric properties and reduced energy gap, making them promising candidates for low-frequency devices such as UV photodetectors, optoelectronics, and spintronics applications. The use of a cost-effective and scalable synthesis method, coupled with detailed material characterization, makes this work significant in the field of nanomaterials and device engineering.

Synthesis and characterization of cobalt-strontium co-doped zinc oxide nanoparticles by chemical precipitation

This study presents a meticulous investigation into the synthesis and characterization of zinc oxide (ZnO) nanoparticles co-doped with cobalt (Co) and strontium (Sr) using the co-precipitation method. Varied doping ratios were employed to create Zn1-(x+y)CoxSryO nanoparticles to synergize the advantageous properties of Co and Sr dopants. Comprehensive characterization was performed, encompassing X-ray diffraction (XRD), UV–VIS spectroscopy, Raman spectroscopy, field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray analysis (EDAX). Contrary to prior assumptions, our XRD analysis revealed that the wurtzite crystal structure of ZnO remained unaltered with Co and Sr doping. FESEM and EDAX characterized the nanoparticle size, morphology, and composition, providing essential insights into the structural changes induced by the doping process. Furthermore, a red shift in the bandgap was observed upon doping, suggesting potential alterations in the optical properties. Our study aims to contribute to the ongoing exploration of ZnO-based nanomaterials by presenting a detailed analysis of the structural and optical modifications by Co-Sr co-doping. The findings offer valuable insights for further understanding nanoscale modifications and their potential applications in optoelectronics, photovoltaics, and photocatalytic systems. Our comprehensive analysis enriches the understanding of the synthesized nanoparticles and their potential applications.

Boosting inverted type organic solar cell efficiency through the use of spray coated Y and Sn co-doped zinc oxide nanoparticles as an electron transport layers

Boosting inverted type organic solar cell efficiency through the use of spray coated Y and Sn co-doped zinc oxide nanoparticles as an electron transport layers

Structural co-related optical properties of Al and Cu co-doped ZnO nanoparticles

Zinc oxide (ZnO) is known to exhibit multifunctional properties for a variety of applications, including gas sensing, light-emitting diodes, optoelectronics and transparent electronics. Doping in ZnO may induce defect states, thereby influencing its physical properties. Here, the simultaneous substitution with Al and Cu is attempted in ZnO in order to tune its optical properties. The morphological, structural, optical and photoluminescence properties were thoroughly investigated using different characterization tools. The phase purity of the Al and Cu co-doped ZnO nanoparticles is confirmed by X-ray diffraction, Fullprof, XPS and Raman spectroscopy. The nanoparticles possess an agglomerated spherical-shape-like morphology, as evident from SEM images. The co-doped ZnO nanoparticles reveal a band gap of ∼3.2 eV. Photoluminescence and time-resolved photoluminescence spectroscopy show the presence of various defect states in ZnO which can tune its optical properties as per the desired application.

Structural and Photoluminescence Properties of Pr, Cu Co-Doped ZnO Nanoparticles Synthesized by Chemical Co-Precipitation Method

At room temperature, zinc oxide (ZnO) nanoparticles co-doped with praseodymium (Pr) and copper (Cu) using a low-cost chemical co-precipitation method. As a capping agent, polyvinylpyrrolidone (PVP) was used for synthesizing the nanosamples, and a pH of 9 was maintained. The synthesis of nanosamples was then characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and photoluminescence (PL). X-ray diffraction studies revealed the wurtzite hexagonal structure of ZnO, and no impurity peaks were found. The particle size obtained from XRD studies was 32 to 46 nm and is well supported by TEM. SEM micrographs demonstrated the surface morphology of the samples. With Cu dopant concentration, Pr-doped ZnO nanosamples exhibited enhanced luminescence properties.

Pseudocapacitance behavior of copper and nickel co-doped zinc oxide nanoparticles with enhanced photocatalytic performance

Pseudocapacitance behavior of copper and nickel co-doped zinc oxide nanoparticles with enhanced photocatalytic performance

Characterization and evaluation of the therapeutic benefits of pure and lanthanides mono- and co-doped zinc oxide nanoparticles

The effect of Lanthanides-doping on the structural, optical, morphological, antibacterial and anticancer properties of zinc oxide (ZnO) nanoparticles was investigated. Pure ZnO, Zn0.9La0.1O, Zn0.9Ce0.1O, and Zn0.9La0.05Ce0.05O were fabricated through the chemical co-precipitation route. The structural and morphological properties were studied using the X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The optical properties were analyzed by photoluminescence spectroscopy (PL). The inhibitory effect of the synthesized nanoparticles (NPs) was assessed against six bacterial strains using the agar well diffusion and broth micro-dilution methods. The anticancer potential of the synthesized NPs was assessed against two human colon cancer cell lines Caco-2 and HCT-116. The appearance of the La2O3 and CeO2 secondary phases upon doping La3+ and Ce3+ ions induced structural and morphological changes. The large distorted hexagonal morphology of pure ZnO is transformed into small sized distorted hexagonal form. The photoluminescence spectra revealed the point defects resulting from Lanthanum (La) and cerium (Ce) doping. The prepared NPs significantly inhibited the growth of the six investigated bacteria and induced cytotoxic effects and morphological changes against Caco-2 and HCT-116 cell lines. This study showed that doping ZnO with lanthanide ions such as La3+ and Ce3+ provide promising biological applications. These NPs showed a potent antibacterial and anticancer effect towards the investigated bacterial strains and colon cancer cell lines. These findings point to the importance of the biological applications of NPs, and the possibility of investigating other biomedical applications for NPs.

In Vitro Antimicrobial and Anticancer Peculiarities of Ytterbium and Cerium Co-Doped Zinc Oxide Nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) are a promising platform for their use in biomedical research, especially given their anticancer and antimicrobial activities. This work presents the synthesis of ZnO NPs doped with different amounts of rare-earth ions of ytterbium (Yb) and cerium (Ce) and the assessment of their anticancer and antimicrobial activities. The structural investigations indicated a hexagonal wurtzite structure for all prepared NPs. The particle size was reduced by raising the amount of Ce and Yb in ZnO. The anticancer capabilities of the samples were examined by the cell viability MTT assay. Post 48-h treatment showed a reduction in the cancer cell viability, which was x = 0.00 (68%), x = 0.01 (58.70%), x = 0.03 (80.94%) and x = 0.05 (64.91%), respectively. We found that samples doped with x = 0.01 and x = 0.05 of Yb and Ce showed a better inhibitory effect on HCT-116 cancer cells than unadded ZnO (x = 0.00). The IC50 for HCT-116 cells of Ce and Yb co-doped ZnO nanoparticles was calculated and the IC50 values were x = 0.01 (3.50 µg/mL), x = 0.05 (8.25 µg/mL), x = 0.00 (11.75 µg/mL), and x = 0.03 (21.50 µg/mL). The treatment-doped ZnO NPs caused apoptotic cell death in the HCT-116 cells. The nanoparticles showed inhibitory action on both C. albicans and E. coli. It can be concluded that doping ZnO NPs with Yb and Ce improves their apoptotic effects on cancer and microbial cells.

Co-doped zinc oxide nanoparticles embedded in Polyvinylalcohol Hydrogel as solar light derived photocatalyst disinfection and removal of coloured pollutants

In this study Co doped ZnO NPs (CoZnO) were synthesized by using polyvinyl alcohol hydrogel (PVA HG) as platform for methyl orange dye (MO) degradation. CoZnO/PVA photocatalysts are not only effective to degrade organic pollutants but also used for disinfection the water. Co-doped zinc oxide nanoparticles (CoZnO NPs) as an excellent photocatalyst were synthesized by the coprecipitation method. ZnO NPs due to its large band gap is only UV light mediated photocatalyst which is only 4% of solar spectrum. In order to fully utilize of solar spectrum, low cast Co transition metal was doped to ZnO NPs to make is visible light derived photocatalyst by lowering its band gap. A high adsorption power of PVA HG enhance photocatalyst activity. For this purpose, Polyvinyl alcohol hydrogel was used along with Co doped ZnO NPs to enhance the photocatalytic activity. Polyvinyl alcohol hydrogel (PVA HG) was prepared by basic hydrolysis of polyvinyl acetate gel which was prepared by free radical emulsion method using diacrylate crosslinker. Co-doped ZnO NPs were formed in the PVA HG matrix by coprecipitation method. The doping concentration of Co was changed from 0-16%(w/w). and optimized for best photocatalytic ability. The 12% Co-doped ZnO NPs showed best photocatalytic ability. So, 12CoZnO NPs were incorporated in the PVAHG for dye degradation and disinfection study. The 12CoZnO/PVA yielded composite showed an extreme rise in photocatalytic efficiency and completely mineralized MO in 48 min. The prepared composite showed better degradation of methylene blue than 12CoZnO NPs under UV-vis light radiation. The stability of PVA/CoZnO NC for photodegradation of dye was verified by a recycling experiment of the composite.

Photodegradation studies of pure and cobalt doped zinc oxide nanoparticles

ABSTRACT Pure and cobalt (Co)-doped zinc oxide (ZnO) nanoparticles were synthesised by co-precipitation method. Various characterisation studies such as powder X-ray diffraction, scanning electron microscope (SEM) and UV-visible spectra were carried out to investigate their structural and optical characteristics. The absorbance spectrum shows the red shift for the Co-doped ZnO nanoparticles and also decrease in their band gap due to increase in dopant concentration. The SEM analysis reveals that the pure ZnO has spherical-shaped morphology and Co-doped samples have hexagonal-shaped nanorods and nanoflowers. Photo catalytic activity of pure and Co-doped Zinc oxide was analysed using Malachite Green and Chrysodine Y dyes under UV irradiation, and it shows good photo catalytic behaviour.

Nano Synthesis and Characterization of Co and Mn Co-doped ZnO by Solution Combustion Technique

Pure zinc oxide (ZnO) and Co and Mn co-doped ZnO nanoparticles were synthesized via a solution combustion technique. Structural, compositional, morphological, functional, optical, magnetization, and photoluminescence properties were examined. X-ray diffraction studies confirmed the hexagonal structure, and the average crystallite size of the synthesized samples was found to be around 20 to 30 nm. From the SEM analysis, all synthesized samples were spherical. Energy dispersion spectra confirm the presence of all selective elements in the synthesized samples. From UV-Vis spectra, we observed that there is decrease in band gap with increase in Co/Mn concentration. From photoluminescence (PL) studies, a decrease in the rate of recombination of electron-hole pair generation is observed. Experiments carried out using vibrating sample magnetometer studies revealed magnetic properties that indicate ferromagnetism in synthesized samples at room temperature. This material offers enormous potential to develop spintronics and optoelectronic materials due to its low cost and good yield.

Antibacterial properties of aluminium, magnesium/nickel co-doped zinc oxide nanoparticles

Antibacterial properties of aluminium, magnesium/nickel co-doped zinc oxide nanoparticles

Electrical behavior and enhanced photocatalytic activity of (Ag, Ni) co-doped ZnO nanoparticles synthesized from co-precipitation technique.

Methylene blue (MB) dye is the most common harmful, toxic, and non-biodegradable effluent produced by the textile industries. The present study investigates the effect of zinc oxide (ZnO) nanoparticles (NPs) and Ag-Ni doped ZnO NPs on the performance of photocatalytic degradation of MB dye. Pure ZnO and Ag-Ni doped ZnO NPs are synthesized using the co-precipitation method. The crystalline nature and surface morphology of the synthesized pure ZnO and Ag-Ni doped ZnO NPs was characterized by powder X-ray diffraction, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM) analysis. The presence of spherical-like morphologies was confirmed from SEM and HRTEM analysis. The presence of Ni-O and Zn-O bands in the synthesized materials was found by Fourier transform infrared (FTIR) spectroscopy analysis. The MB dye was degraded under UV-light exposure in various pH conditions. The Ag (0.02%)-Ni doped ZnO NPs exhibits highest photocatalytic activity of 77% under pH 4.

Photoluminescence and enhanced photocatalytic activity of ZnO nanoparticles through incorporation of metal dopants Al and Ca

In the present work influence of aluminium and calcium in the structural, optical properties and the photocatalytic performance of zinc oxide (ZnO) nanoparticles are studied. Pure, 2 wt% aluminium doped, 2 wt% calcium doped and 2 wt% aluminium 2 wt% calcium codoped ZnO nanoparticles are synthesized using sol-gel route. The structural, morphological and optical properties are investigated using XRD, SEM, EDAX, UV–vis spectroscopy and photoluminescence spectroscopy. The synthesized nanoparticles are spherical in shape and are crystallized well with wurtize phase. Discrete narrow emission spectra are obtained in photoluminescence spectroscopy. The prepared samples were subjected to photocatalytic degradation with methylene blue dye and a substantial photocatalytic performance is observed with calcium doped ZnO nanoparticles.

Structural, Optical and Magnetic Properties of Pristine, (Mn, Al) co-doped ZnO Nanocrystallites Synthesized via co-Precipitation Method

Undoped and (Mn, Al) co-doped Zinc Oxide nanoparticles are synthesized by chemical co-precipitation method at room temperature effectively via poly ethylene glycol (PEG) as stabilizing agent. XRD data reveals that all the concentrations acquire hexagonal wurtzite crystal structure with no secondary peaks concerning to Al or Mn, indicating successful dissolution of Al and Mn in to ZnO host lattice. The exact particle size is estimated using TEM illustrations, which is confirmed through the XRD results. EDS spectrum shows, no impurities are present in the samples other than manganese and aluminum. The absorption spectra of all the samples reveal characteristic absorption edge in the vicinity of 375 nm. PL spectra show that all the concentrations include defect associated peaks in the visible region. VSM measurements reveal the ferromagnetic nature for co-doped samples. Copyright © VBRI Press.

Effect of (Ag, Pd) doping on structural, and optical properties of ZnO nanoparticales: As a model of photocatalytic activity for water pollution treatment

This study presents a favorable application to use (Ag, Pd) co-doped Zinc oxide nanoparticles as nanocatalysts in photocatalytic degradation of maxilon blue (GRL) dye. Un-doped ZnO nanoparticles were prepared by hydrothermal method and Ag, Pd and (Ag, Pd) co-doped ZnO nanoparticles by photochemical methods for photocatalytic application. XRD results revealed that ZnO has a hexagonal wurtzite phase with (1 0 1) plane preferred orientation. FE-SEM results demonstrated that the samples with a high agglomeration except at pH11 that have a rod-like shape. FT-IR absorption peak at ~520 cm−1, revealed a slight shift which observed after the doping between (520 and 450) cm−1. Diffuse reflectance shows the band gab of doped ZnO nanoparticles is at 2.61 eV. PL results indicate that (Ag, Pd)/ZnO has a lower recombination rate when compared with Ag or Pd doped ZnO nanoparticles. Novel photocatalytic high activity were observed for (Ag, Pd) co-doped ZnO which is about 95.67% at pH9.

Defect induced room temperature ferromagnetism and optical properties of (Co, Y) co-doped ZnO nanoparticles

Abstract In this work, pristine zinc oxide (ZnO), Co2+ doped zinc oxide (ZCO) and Co-Y co-doped zinc oxides (ZCYO) are synthesized by sol-gel method. To increase the oxygen vacancy, the as-prepared samples are annealed in vacuum furnace. Refinement of the recorded X-ray diffractograms (XRD) shows that all the samples have grown in single hexagonal phase with space group P63mc and the nanocrystallites are grown with average sizes lie in the nanometer regime (10–29 nm). Fourier-transform infrared spectroscopy (FTIR) and photoluminescence (PL) spectroscopy could not detect any secondary phase except the desired one. Interestingly, room temperature ferromagnetism (RTFM) is observed in Co-Y co-doped sample where maximum magnetization is quite high (∼0.34 emu/g) compared with undoped ZnO. Absence of any metal cluster in ZCYO by XRD and optical analyses ruled out the ordering due to clustering. Thus origin of RTFM in ZCYO is intrinsic in nature. The defect mediated RTFM observed in ZCYO nanoparticles due to exchange interaction between dopants ions is explained by the oxygen vacancy together with the presence of the increase of surface defects due to co-doping of Co ion and non-magnetic Y ion.