Undoped Particles Research Articles

W–CeO2 Core–Shell Powders and Macroscopic Migration of the Shell via Viscous Flow during the Initial Sintering Stage

To retard the mutual contact of W grains to inhibit their growth, in this study, CeO2·2H2O was first coated on the surface of pure W (undoped) particles by a weight percentage of 4% using a wet chemical method to prepare CeO2·2H2O-doped W-based (doped) powders, with W particles as the core and CeO2·2H2O as the shell (W–CeO2·2H2O core–shell structure), without hydrogen reduction treatment. The undoped and doped powders were subsequently sintered using a spark plasma sintering (SPS) apparatus to fabricate bulk materials. The macroscopic migration of the CeO2 shell in the core–shell W–CeO2 system via viscous flow during the initial sintering stage was studied through simulations and experiments. The results showed that a core–shell structure with W particles as the core and CeO2·2H2O as the shell was successfully prepared. The doped powder contained approximately 3.97% CeO2, consistent with the designed content of 4%. The shell materials migrated among the selected four sintered powders, filling the pores and contributing to the improvement in the relative density of the sintered bulk.

Enhanced thermochemical energy storage properties of SiC-doped calcium-based material with steam addition during heat charging process

Thermochemical energy storage based on the reversible carbonation/calcination reaction of CaCO3/CaO is emerging as a promising technology for energy storage in concentrating solar power systems. However, the inherent weak solar absorption capacity of natural calcium-based materials necessitates a substantial enhancement in their solar absorption capability. In this study, dark SiC particles of different sizes were introduced into CaO-based composite particles supplemented with cement and microcrystalline cellulose. The aim was to explore the influence of SiC components on the solar absorptivity, energy storage capacity, thermal conductivity, and mechanical properties of CaO-based particles. The results indicate that doping 10 wt% of SiC with a size of 25 μm in CaO-based particles demonstrated optimal results, corresponding to a 20.3 % increase in the average optical absorption and a 2.86-fold improvement in the thermal conductivity compared to the undoped particles. Furthermore, introducing steam during the decomposition of SiC-doped CaO-based particles significantly enhanced the mechanical properties. The breaking force of SiC-doped CaO-based pellets after 50 runs with 10 vol% steam addition was 1.39 times higher than that of the identical particles without steam treatment.

Enhancing dielectric properties of ZnO nanopowders with 2D hBN doping: production, structural, morphological and dielectric characterization

In this study, it was aimed to improve the dielectric properties of ZnO nanoparticles with the addition of hBN, which was not previously available in the literature, and thus to expand their usage areas. Sol–gel synthesis method was used in this study to create pure and hexagonal boron nitride (hBN) doped zinc oxide (ZnO) nanoparticles. Zinc acetate dihydrate Zn(CH3COO)22H2O), sodium hydroxide NaOH, and hexagonal boron nitride (hBN), all from Sigma Aldrich, were used as starting reagents. The reagents were dissolved during the sol–gel synthesis by being heated to 90 °C for 4 h in a magnetic stirrer. FT-IR, XRD, FE-SEM, EDX characterization techniques, and impedance analyzer were used to find functional groups, structural, morphological, and chemical composition, and dielectric properties of the nanoparticles, respectively. The produced un-doped and hBN-doped ZnO particles consist of nano-sized structures. Changes occurred in the intensities and locations of the XRD diffraction peaks and FT-IR peaks with the addition of hBN. Characteristic peaks of both ZnO and hBN were observed in the diffraction peaks of the doped nanoparticles. All nanoparticles were of high purity and were successfully produced by the sol–gel method. It was shown that as the hBN doping level increased, there were more hBN nanoplates in the ZnO matrix, and the EDX results also showed an increase in hBN addition. The frequency stability of the dielectric properties improved after hBN doping. While the dielectric constant at 1 kHz frequency at room temperature is 12.07 in pure ZnO nanoparticles, the increase up to 55.21 is observed in 10% hBN doped nanocomposites. This situation is considered as a great potential for technological applications of this novel nanocomposite material.

A review on ultra‐small undoped MoS2 as advanced catalysts for renewable fuel production

AbstractMolybdenum disulfide (MoS2) has garnered significant attention in the field of catalysis due to the high density of active sites in its unique two‐dimensional (2D) structure, which could be developed into numerous high‐performance catalysts. The synthesis of ultra‐small MoS2 particles (<10 nm) is highly desired in various experimental studies. The ultra‐small structure could often lead to a distinct S–Mo coordination state and nonstoichiometric composition in MoSx, minimizing in‐plane active sites of the 2D structure and making it probable to regulate the atomic and electronic structure of its intrinsic active sites on a large extent, especially in MoSx clusters. This article summarizes the recent progress of catalysis over ultra‐small undoped MoS2 particles for renewable fuel production. Through a systematic review of their synthesis, structural, and spectral characteristics, as well as the relationship between their catalytic performance and inherent defects, we aim to provide insights into catalysis over this matrix that may potentially enable advancement in the development of high‐performance MoS2‐based catalysts for sustainable energy generation in the future.

Synthesis, characterization, photocatalytic application of Gd/K co‐doped ZnO

AbstractIn this paper, we introduce the synthesis of undoped ZnO and 5 wt % Gd/K co‐doped ZnO compounds to improve photocatalytic activity. Undoped ZnO particles and Gd/K co‐doped ZnO particles were synthesized by the sol‐gel method. The samples were studied by X‐ Ray Diffraction (XRD), Scanning Electron Microscopy (SEM)/energy dispersive X‐ray (EDX), Ultraviolet Visible Spectroscopy (UV‐Vis), Brunauer–Emmett–Teller (BET), and particle size analysis. Then tehir photocatalytic activities were tested. SEM micrographs showed that the particle size was in the sub‐micrometer or nanometer range. Particle size analysis revealed that the mean size was closer to the micrometer range. The specific surface area of the powder was obtained quite low in accordance with the larger particle size. The photocatalytic activity of 5% Gd/K co‐doped ZnO was compared with undoped ZnO in the degradation methyl blue. When their photocatalytic activities were examined, Gd/K co‐doped ZnO showed ∼66% degradation at 60 min, while undoped ZnO showed ∼52% degradation at the same time.

Long-term replenishment strategy of SiC-doped Mn-Fe particles for high-temperature thermochemical energy storage

Thermal chemical energy storage (TCES) is a promising technology for large-scale energy storage, but long-term use of TCES materials can lead to attrition and reaction performance deterioration, compromising heat storage capacity and system continuity. To tackle this challenge, it is imperative to develop effective replenishment strategies and investigate the evolution of TCES materials. In this study, SiC-doped Mn-Fe particles exhibited superior performance, with only 1.87% mass loss ratio after 4.32×105 rotations attrition testing and a reaction conversion of 91.7% even after 800 reaction cycles. However, assessing material suitability for TCES systems necessitates analyzing both attrition resistance and reaction performance. A replenishment strategy was proposed, based on the attrition conversion factor and analysis of dissipated energy of particles in concentrated solar power (CSP) plants. Compared to undoped Mn-Fe particles, the annual replenishment ratio was reduced by one order of magnitude for SiC-doped particles, to only 1.26% (0.5 wt% SiC) and 0.994% (1 wt% SiC). The replenishment strategy and strengthened particles result in curtailed particle fines and particle flow interruption, and enhanced economics. Continuous replenishment strategy can undoubtedly cater to the requisite heat storage capacity demands for protracted system operation and extend system stability, promoting the advancement of TCES technology.

Synthesis and Characterization of Novel Sprayed Ag-Doped Quaternary Cu2MgSnS4 Thin Film for Antibacterial Application.

In this work, the effects of silver doping with different Ag/(Ag + Cu) ratios (i.e., 2%, 5% and 10% at.% in the spray solution) on the structural, morphological, optical, electrical and antibacterial properties of Cu2MgSnS4 (CMTS) thin film grown by spray pyrolysis have been studied. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) results have shown that the kesterite phase of CMTS thin films has a maximum crystallite size of about 19.60 nm for 5% Ag/(Ag + Cu). Scanning electron microscopy (SEM) images have shown spherical grain shapes. The transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) microscopy observations confirmed the intrinsic reticular planes of CMTS thin film with (112) as a preferred orientation and interplanar spacing value of 3.1 Å. The optical properties showed high absorbance and an absorption coefficient of about 104 cm−1 in the visible region with an optical band gap energy of 1.51 eV. Impedance analysis spectroscopy demonstrated good electrical properties of the CMTS film obtained using 5% Ag/(Ag + Cu). The antibacterial activity of the undoped and Ag-doped particles of CMTS obtained using 5% Ag/(Ag + Cu) against different strains of pathogenic bacteria was tested using the agar well diffusion method. These results showed a significant antibacterial activity of the Ag-doped CMTS particle, which was much higher than the undoped CMTS particles. These experimental findings may open new practices for the Ag-doped CMTS compound, especially the one obtained using 5% Ag/(Ag + Cu), in antibacterial application.

Ceria nanoparticles as promoters of CO2 electroreduction on Ni/YSZ: An efficient preparation strategy and insights into the catalytic promotion mechanism

Since many decades nickel yttria-stabilized zirconia cermet (Ni/YSZ) has been the most frequently used fuel electrode material for high temperature solid oxide cells (SOCs). However, in recent years there has been considerable effort to improve the Ni/YSZ performance through surface engineering. In this work, we report a simple strategy to apply nanosized un-doped (CeOx) and Ni-doped (NiCeOy) ceria particles into porous Ni/YSZ cermet electrodes via infiltration from hexane solution. Detailed characterization of the particles in their solution revealed differences in the ease of agglomeration, with NiCeOy nanoparticles being better dispersed and thus forming smaller aggregates. This property is critical for the effectiveness of the solution in filling the pores of Ni/YSZ cermet and the consequent ceria deposition. In particular, morphological and microstructural characterization reveals that NiCeOy nanoparticles decorate uniformly the pores of Ni/YSZ backbone, deep up to the interface with the electrolyte. More importantly, this can be done with relatively high ceria loading per infiltration/co-firing step. Electrochemical tests demonstrate that infiltrated Ni/YSZ fuel electrodes have improved I-V performance in CO2 electrolysis as compared to pristine Ni/YSZ. Synchrotron-based operando NAP-XPS experiments using both soft and tender X-rays revealed the formation of an ultrathin Ni-Ce3+ layer on the electrode surface, which can rationalize the ameliorated CO2 electrolysis performance.

Ag nanoparticle-decorated chitosan/SrSnO3 nanocomposite for ultrafast elimination of antibiotic linezolid and methylene blue.

Effective design of ultrafast new-generation photocatalysts is a challenging task that requires highly dedicated efforts. This research focused on the development and design of ultrafast smart ternary photocatalysts containing SrSnO3 nanostructures in conjugation with chitosan (CTSN) and silver (Ag) nanoparticles by a very simple and straightforward methodology. Modern analytical tools such as FESEM, TEM, XRD, XPS, FTIR, and UV-Vis spectroscopy were employed to characterize the synthesized nanostructures. XRD and XPS analysis confirmed the successful creation of ternary organization among the Ag, CTSN, and SrSnO3. The TEM images clearly confirmed that CTSN possessed overlapping micron-sized sheets with a layered morphology, whereas the undoped SrSnO3 particles exhibited spherical and elongated shapes and particle sizes ranging from 20 to 80 nm. These particles were produced in high density with homogeneously distributed Ag nanoparticles (4-15 nm). The bandgap energy (Eg) for bare SrSnO3, CTSN/SrSnO3, and Ag@CTSN/SrSnO3 nanocomposites was found to be 4.0, 3.94, and 3.7 eV, respectively. The photocatalytic efficiencies of all newly created photocatalysts were evaluated by considering an antibiotic linezolid drug and methylene blue (MB) dye molecule as target analytes. Among all investigated samples, the Ag@CTSN/SrSnO3 photocatalyst was found to be highly superior, with ultrafast removal of the linezolid drug at 96.02% within 25 min and almost total removal of the MB dye in just 12 min under UV light irradiation. The Ag@CTSN/SrSnO3 photocatalyst exhibited removal rate that was 3.36 times faster than that of bare SrSnO3. The present report delivers a highly promising, extremely efficient, and very simple, straightforward treatment methodology for the effective destruction of lethal and notorious pollutants, enabling the appropriate management of current environmental concerns.

Photoluminescence Investigation of Tb Doped Yb2O3 Phosphors Produced by Precipitation Method

Un-doped and Tb doped ytterbium oxide (Yb2O3:Tb3+) particles with different dopant rates (2, 4, 6 and 8 at. %) were produced by precipitation method, subsequently by calcination at 1000 °C for 2 h. The crystal structure of all the particles had cubic Yb2O3 structure. The presence of Tb ion in Yb2O3 host structure has been proven from the XRD results. The crystal structure expanded compared to un-doped Yb2O3 particles with the dopant addition confirming lattice parameter (LP) values. LP and crystallite size (CS) values were in the range of 10.428 – 10.596 Å and 16 – 25 nm, respectively. Only one sharp peak was observed at 506 nm corresponding to 5D4 – 7F6 transition (green emission) from photoluminescence (PL) spectra of the phosphor particles. The PL emission intensities were strongly dependent on both CS and dopant rate. However, the dopant rate was more effective on the PL intensity than the CS.

Structural changes of Nd- and Ce-doped ammonium diuranate microspheres during the conversion to U1−yLnyO2±x

The structural changes of ammonium diuranate (ADU) microspheres, prepared by the sol–gel route via internal gelation, were investigated during thermal treatments in oxidative and reducing conditions. In particular, in-situ simultaneous thermogravimetric analyses and in-situ high-temperature scanning electron microscopy investigations were carried out on un-doped ADU microspheres, and ADU microspheres doped with 10 mol% neodymium or 10 mol% cerium. Calcination in air caused the surface of the particles to crack, but with increasing temperature up to 900 °C some healing, and additionally, shrinkage occurred. The extent of the fractures and the amount of shrinkage was, however, significantly more pronounced in a particle prepared with a tetravalent Ce precursor, as compared to particles prepared with a trivalent Nd or Ce precursor. The macroscopic behaviour could be related to the release of volatile decomposition products and the calcined compositions were identified as (Ln-doped) α−U3O8by X-ray powder diffraction. During thermal treatment in reducing conditions a transition from a (Ln-doped) α−U3O8phase to a (Ln-doped) UO2±x phase was observed. After exposure to a hydrogen containing gas mixture, this transition occurred rapidly in un-doped particles, and in particles prepared with trivalent Nd or Ce dopant precursors at 700 °C. Despite the fast reduction reaction, severe fractures appeared in the particles above temperatures of 850 °C, indicating that such behaviour is mainly attributed to sintering effects and less to the phase transition. In contrast, a more delayed reduction reaction was observed in particles prepared with a tetravalent dopant precursor and the described effects appeared less severe.

Enhanced detection using stable isotope enriched 65Cu doped ferrite nanoparticles for tracing studies

65Copper stable isotope doped ferrite nanoparticles with two dopant concentrations were prepared by a co-precipitation method for conducting biomedical experiments at environmentally relevant concentrations. The synthesized (65CuxFe1-xFe2O4) nanoparticles were of 30 ± 7 nm in size and the VSM measurements showed a magnetic moment of 30 emu/g of un-doped ferrite particles at 310 K. The amount of 65Cu doped in the ferrite nanoparticles were calculated using ICP-MS. Cytocompatibility studies were performed through cellular toxicity assays on WRL68 liver cell line. MTT and ROS assay demonstrated cell viability in an order of Fe3O4>65Cu0.088Fe2.085O4>65Cu0.143Fe3.31O4. The cytocompatibility and magnetic measurement data set indicate that by doping a small amount of copper, the ferrite nanoparticles can retain their magnetic properties and the cytocompatibility is not severely compromised. 65Cu0.088Fe2.085O4 (d1-Fe3O4) and 65CuO nanoparticles were used for tracing experiments, wherein, even at a lower exposure concentration of 0.5 μg/mL, 65Cu can be detected in the media even when the copper background concentration is high. The results indicate the ability to perform biological studies at low exposure concentrations with enhanced detection ability. The proposed technique shows that isotope enriched copper doped ferrite can serve the purpose of quantifiable traceable nanocarriers.

Synthesis, characterization, and application of transition metals (Ni, Zr, and Fe) doped TiO2 photoelectrodes for dye-sensitized solar cells

In this paper, we present the synthesis of different metal-doped TiO2 compounds (pure TiO2, Fe doped TiO2 (FexTi1-xO2), Ni doped TiO2 (NixTi1-xO2), Zr doped TiO2 (ZrxTi1-xO2)) thin films in order to improve the performance of dye-sensitized solar cell (DSSC). Undoped TiO2 particles and Ni, Fe and Zr transition metals doped TiO2 particles were synthesized by the sol-gel method for the utilization of the anodic part of the DSSC. The cathode of the DSSC was a carbon electrode. Fluorine Doped Tin Oxide (FTO) coated electrodes on the glass surfaces and electrolyte solution containing I/I2 was obtained a dye-sensitized solar cell. Pure TiO2 and Ni, Fe and Zr doped TiO2 nanopowders were characterized by DLS, XRD, SEM/EDX, and UV–Vis Spectroscopy. The thin films have been deposited on the glass substrate by the doctor blade method. The effect of synthesized nano-materials on the cell performance of DSSC was investigated by J-V curves. J-V characterization of solar cell module shown that the highest power conversion efficiency was the solar cell module that fabricated with 10% of Zr doped TiO2 with the short circuit current (Jsc) and the efficiency was at 0.13 mA cm−2 and 0.020%, respectively. However, yields on the cell performance of other nanomaterials were obtained as 0.019%, 0.017% and 0.015% for pure TiO2, Fe doped TiO2, and Ni doped TiO2, respectively.

Alumina-Doped Zirconia Submicro-Particles: Synthesis, Thermal Stability, and Microstructural Characterization.

Zirconia nanoceramics are interesting materials for numerous high-temperature applications. Because their beneficial properties are mainly governed by the crystal and microstructure, it is essential to understand and control these features. The use of co-stabilizing agents in the sol-gel synthesis of zirconia submicro-particles should provide an effective tool for adjusting the particles’ size and shape. Furthermore, alumina-doping is expected to enhance the particles’ size and shape persistence at high temperatures, similar to what is observed in corresponding bulk ceramics. Dispersed alumina should inhibit grain growth by forming diffusion barriers, additionally impeding the martensitic phase transformation in zirconia grains. Here, alumina-doped zirconia particles with sphere-like shape and average diameters of were synthesized using a modified sol-gel route employing icosanoic acid and hydroxypropyl cellulose as stabilizing agents. The particles were annealed at temperatures between 800 and 1200 and characterized by electron microscopy, elemental analysis, and X-ray diffraction. Complementary elemental analyses confirmed the precise control over the alumina content (0–50 mol%) in the final product. Annealed alumina-doped particles showed more pronounced shape persistence after annealing at 1000 than undoped particles. Quantitative phase analyses revealed an increased stabilization of the tetragonal/cubic zirconia phase and a reduced grain growth with increasing alumina content. Elemental mapping indicated pronounced alumina segregation near the grain boundaries during annealing.

Comparison of structural and optical properties of CeO2 and CeO2:Eu3+ nanoparticles synthesized via sol–gel and flame spray pyrolysis methods

Over the last decades, a considerable attention has been drawn on the cerium dioxide (ceria, CeO2) due to promising changes in physical and chemical properties in nanoscale. The researches on CeO2 and its structural and morphological modifications have brought about remarkable applications as optical devices, sensors, medical equipments and luminescent materials. For instance, rare earth (RE) ion-doped cerium oxides have exhibited enhanced peculiar optical, catalytic and magnetic properties with respect to the dopant-free CeO2 nanoparticles. Herein we aimed to compare characteristics of undoped (CeO2) and europium (Eu3+) doped ceria (CeO2:Eu3+) nanoparticles synthesized by sol–gel (SG) and one-step flame spray pyrolysis (FSP) methods. In this work, fabricated nanoparticles were evaluated in terms of the structural, morphological, chemical and optical properties by using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron (XPS) and photoluminescence spectroscopy (PL), respectively. Nanoparticles in the intended crystalline CeO2 structure were obtained for both methods. Spherical particles in nanoscale (particle size < 100 nm) and sharp edged blocky particles in sub-micron size (particles size range 200–1000 nm) were produced through FSP and SG, respectively. Nevertheless, no significant difference due to the difference in particle size was observed in optical properties. On the other hand, Eu3+ doped particles of both methods exhibited longer decay time than the undoped particles.

Room Temperature Ferromagnetism in Fe Doped CdS and Cobalt Doped CdS Nano Particles

The undoped and doped cadmium sulphide nano particles were prepared by co precipitation technique at room temperature.The effect of nano stochiometry on structural , micro structural properties of the powders were studied. The structural properties of the nano powders were investigated by X ray diffraction. The Scanning Electron Microscopic studies were carried out using (Quanta FEG 250) and Elemental Analysis was carried out with an EDAX using Energy dispersive X ray spectrophotometer. The particle size was also calculated and compared.The room temperature ferromagnetism of the doped and undoped cadmium sulphide nano particle I also investigated using vibrating sample magenetrometer.

Sodium Doping Effect on Optical Permittivity, Band Gap Structure, Nonlinearity and Piezoelectric Properties of PZT Nano-colloids and Nanostructures

In this research, effects of sodium atoms doping on optical properties of lead zirconate titanate (PZT) nanoparticles (NPs) are studied and compared with undoped particles. Analyses show formations of PZT nanostructures with dimensions below 30 nm. X-ray diffraction patterns show that the particle size increases and the intensity of the preferred direction decreases as the doping sodium atoms are used in the structure. Analyzing absorption spectra of the colloidal solutions shows doped particles are better absorbers at violet-green region of spectra. Also, it has been concluded that PZT NPs only have indirect optical band gap that is narrower for doped particles. Optical permittivity of the films has been compared using a numerical method and shows the prominent effect of doping on real and imaginary parts of permittivity. Also, z-scan experiments have been done to measure thermo-optical and nonlinear absorption coefficients of the nano-colloids using continue wave Nd-YAG laser illumination. Finally, sodium doping effects on piezoelectric properties of the samples are investigated using a Michelson interferometer.

Synthesis of Sn‐doped ZnO hierarchical particles and their gas‐sensing properties

In this work, un-doped and Sn-doped hierarchical ZnO particles with high dispersity were successfully fabricated by a facile liquid reaction. The prepared samples are characterised by X-ray diffraction and scanning electron microscopy. The as-synthesised hierarchical ZnO particles with a diameter of ∼1.5 μm were obtained by considerably intersecting thin nanosheets of ∼20 nm thickness. The morphology of ZnO structures can be varied by adjusting reaction parameters, e.g. reaction temperature, calcination temperature, and dopant concentration. On the basis of experimental results, the gas-sensing measurement displays that the sensor based on Sn-doped ZnO microstructures have a low detection of 10 ppm ethanol at an operational temperature of 250°C, demonstrating its outstanding gas-sensing performance. Therefore, the flower-like Sn-doped ZnO have prospective applications in a multifunction ethanol sensor. Moreover, the fabrication method reported in the work is facile, flexible and operable, it is possible to extend to synthesise other types of metal oxide-based applications in various fields.

Nucleation-controlled hysteresis in unstrained hydrothermal VO2 particles

While nucleation-limited transformation mechanisms are widely implicated in unstrained, undoped $\mathrm{V}{\mathrm{O}}_{2}$ nanoparticles, a direct link between nucleation barriers and hysteresis widths has not yet been established. Here, we investigate microscopic transformation of structural domains optically in hydrothermally grown $\mathrm{V}{\mathrm{O}}_{2}$ particles \ensuremath{\sim}0.5--46 \ensuremath{\mu}m in length, which are not elastically clamped to the substrate. We observe abrupt and generally complete transformation in individual particles, consistent with a nucleation-limited transformation mechanism. The forward and reverse transformation temperatures are not correlated, suggesting a range of potency of nucleation sites for both forward and reverse transformation in undoped particles, resulting in a hysteresis of 2.9--46.3 \ifmmode^\circ\else\textdegree\fi{}C. Thus, the macroscopic hysteresis width in bulk $\mathrm{V}{\mathrm{O}}_{2}$ powders and dispersed particulate films is primarily attributable to a distribution of critical nucleation temperatures between different particles. These findings suggest that as $\mathrm{V}{\mathrm{O}}_{2}$ volume elements are scaled down for microelectronic applications, manipulation of nucleation sites via defect engineering may be required to control the degree of the $\mathrm{V}{\mathrm{O}}_{2}$ element reversibility.

Antimicrobial activity of designed undoped and doped MicNo-ZnO particles

The research objective of the present study was to evaluate antimicrobial activity of ZnO powder systems in different size, shape and array platelet forms with undoped and doped Ag at different concentrations. In particular, a novel particle morphology, called MicNo-ZnO, is micron size hexagonal platelet particles composed of primary nano ZnO particles, and its' doped forms with Ag was tested as an antimicrobial agent as first time in the literature. Eleven test microorganisms were used to investigate antimicrobial performance of particles including Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Candida albicans, Candida glabrata, Candida zeylanoides, Aspergillus flavus, Aspergillus fumigatus, Fusarium solani and Penicillium citrinum. The results show that investigated nanoparticles have broad-spectrum antimicrobial activity. In addition, effectiveness of nanoparticles increases by doping of Ag and especially MicNo particles doped with 0.05 mol % of Ag concentration demonstrated the highest antimicrobial activity among tested particles. These results are considered, MicNo-ZnO display a great potential for different industrial applications.