Synthesis, Characterization and Optical Morphology of ZnO Nanoparticles

The ZnO molecule plays an important role in the industry due to it special features, anti-corrosion anti-bacterial properties, as well as due to its low electrical conductivity and heat resistance. In these experimental researches, the sol-gel method was chosen, which enables control of nucleation, aging and growth of particles in the solution. ZnO synthesis was prepared utilizing chemical method with Zinc acetate dyhidrate and NaOH with the appropriate methanol solvent and heating (60˚C). The methods used in identification and characterization are FTIR, UV/VIS, OPTICAL MICROSCOPY, SEM and XRD. The FTIR spectra of synthesized ZnO with corresponding ones show characteristic bands at the corresponding wavelengths, which confirm the presence of ZnO nanoparticles. SEM characterization of ZnO shows the morphology of needle-shaped nanoparticles. XRD spectar in this research by chemical method indicates the particle size of 17.76 nm.

阴极辉光放电电解制备纳米ZnO

以Pt针为阴极,Zn片为阳极,2 g/L Na_(2)SO_(4)溶液为电解质,在530~650 V放电电压下,利用阴极辉光放电电解(CGDE)技术一步制得纳米ZnO颗粒。用XRD、SEM、FTIR、XPS等对产物的结构、组成和形貌进行了表征,利用UV-Vis DRS计算了纳米ZnO颗粒的带隙能,用UV-Vis研究了纳米ZnO粒子光催化降解亚甲基蓝(MB)的行为,并探讨了其制备机理。结果表明,580 V下得到的纳米ZnO颗粒有一定的团聚,加入表面活性剂聚乙烯吡咯烷酮(PVP)能够抑制纳米ZnO颗粒的团聚;材料的形貌随PVP浓度和放电电压的变化而变化。当电压为530 V、加入0.0031%(质量分数)的PVP时,得到尺寸约200 nm、带隙能为3.22 eV的纺锤状纳米ZnO;随电压升高,颗粒尺寸分布越宽。在紫外光照射30 min后,加入PVP所制备的ZnO光催化降解MB的降解率由78.5%提高到87.3%,说明加入PVP后制备的ZnO光催化性能更优。CGDE制备纳米ZnO的机理为:放电过程中阳极Zn片氧化溶解为Zn^(2+),然后Zn^(2+)迁移到阴极辉光区,与等离子体-液体界面产生的OH-反应生成[Zn(OH)_(4)]^(2-),最后[Zn(OH)_(4)]^(2-)从等离子体-液体界面区转移到溶液中,产生ZnO晶粒。

High Performance Ultraviolet Photodetector Fabricated with ZnO Nanoparticles-graphene Hybrid Structures

Ultraviolet （UV） photodetector constructed by ZnO material has attracted intense research and commercial interest. However, its photoresistivity and photoresonse are still unsatisfied. Herein, we report a novel method to assemble ZnO nanoparticles （NPs） onto the reduced graphite oxide （RGO） sheet by simple hydrothermal process without any surfactant. It is found that the high-quality crystallized ZnO NPs with the average diameter of 5 nm are well dispersed on the RGO surface, and the density of ZnO NPs can be readily controlled by the concentration of the precursor. The photodetector fabricated with this ZnO NPs- RGO hybrid structure demonstrates an excellent photoresponse for the UV irradiation. The results make this hybrid especially suitable as a novel material for the design and fabrication of high performance UV photodector.

Zinc oxide nanoparticles accelerate the healing of methicillin-resistant Staphylococcus aureus(MRSA)-infected wounds in rabbits

Objective:To synthesize zinc oxide nanoparticles(ZnONPs)and evaluate their antibacterial and wound healing effects against wounds infected with methicillin-resistant Staphylococcus aureus(MRSA).Methods:ZnONPs were prepared by sol-gel method and characterized by X-ray diffraction(XRD)analysis and scanning electron microscopy(SEM).A total of 18 rabbits were divided into three groups:the ZnONPs group,the gentamicin group and the control group.A wound of 3 cm^(2) was inflicted on each rabbit and contaminated with MRSA inoculum.Treatment was started from the fourth day post-surgery.Wound healing,microbiological analysis,and histopathological analysis were performed to assess the efficacy of ZnONPs ointment.Results:XRD analysis confirmed the hexagonal wurtzite structure of the ZnONPs with an average crystallite size of 29.23 nm.SEM revealed discoid-shaped ZnONPs with a rough surface and an average size of 48.36 nm.Energy-dispersive X-ray analysis confirmed the purity of ZnONPs.Moreover,the particle size ranged from 100-700 nm with a high agglomeration trend.Treatment with ZnONPs promoted MRSA-infected wound healing.In addition,ZnONPs showed a good antibacterial effect as evidenced by a dose-dependent increase in the zone of inhibition.Conclusions:ZnONPs accelerate the healing of MRSA-infected wounds.Therefore,it can be explored for the treatment of MRSA infection.

Graft modification of ZnO nanoparticles with silane coupling agent KH570 in mixed solvent

The reaction of ZnO nanoparticles grafted with KH570 silane coupling agent was carried out in water-alcohol mixed solvent. Several characterization methods were applied to analyzing the results of surface modification such as Soxhlet extraction, Fourier transform infrared spectroscopy （FT-IR）, transmission electron microscopy （TEM）, thermogravimetry （TG）, differential scanning calorimetry （DSC） and zeta potential （ζ）. The results of FT-IR and TG-DSC show that the desired reaction chains have been covalently bonded on the surface of ZnO nanoparticles. Zetasizer results reveal that the maximal absolute value of ζ of the modified ZnO particles in acetone medium was 67.0 mV, which was much higher than that of the unmodified ZnO particles. So the surface of nanosized ZnO changed from hydrophilicity to hydrophobicity and the dispersity of ZnO nanoparticles were improved simultaneously. Finally, the mechanism of graft modification was discussed.

Highly Ordered Lattice Orientation of ZnO Nanoparticles Formed in Confined Space

Oriented aggregation of nanoparticles has been accomplished by means of solid state reac- tion. Non-crystallized and crystallized ZnO nanoparticles/clusters could be accommodated in the lamellar spacing of inorganic-organic composite, which were prepared by thermolysis of layered solid zinc-oleate complex at 260 and 300 ℃ in air, respectively. High-resolution transmission electron microscopy and selected area electron diffraction patterns indicate that aggregates are single crystals with various defects. The photoluminescence excitation spectra of both samples show two bands at 272 and 366 nm. The former may originate from electron transfer from valence band to conduction band in ZnO clusters composed of less than 200 ZnO molecules （2R〈2 nm）.

Morphology controlled synthesis of ZnO nanoparticles for in-vitro evaluation of antibacterial activity

Novel hierarchical flower-and nanorod-shaped ZnO nanoparticles with uniform morphological features were successfully synthesized through controlled precipitation method in aqueous media without using any surfactant or template.To elucidate the growth mechanism of the synthesized nanoparticles,the effects of pH,reaction time and temperature were studied systematically.Selected ZnO samples were then subjected to SEM,FT-IR and XRD analysis.XRD patterns confirmed well crystalline nature of the as-synthesized powders.Furthermore,synthesized nanoparticles(hierarchical flowers as ZnO-1 and nanorods as ZnO-2),as well as commercial ZnO(ZnO-Com),were then investigated for in-vitro evaluation of antibacterial activity against various bacterial strains of clinical importance.Results showed that ZnO-2 exhibited higher antibacterial activity to all tested strains than ZnO-1,while ZnO-Com showed no antibacterial response in the applied experimental conditions.In addition,ZnO concentration-dependent antibacterial study unfolded that size of inhibition zones increased significantly from^30 to 33 mm against Streptococcus mutans and from^28 to 30 mm against Escherichia coli with increasing ZnO-2 concentration from 0.25 to 0.75μg/μL.The present study,therefore,suggests that the application of synthesized ZnO nanoparticles as the antibacterial agent may be effective for inhibiting certain pathogenic bacteria in biomedical sides.

Indium doping effect on properties of ZnO nanoparticles synthesized by sol–gel method

Pure ZnO and indium-doped ZnO(In–ZO) nanoparticles with concentrations of In ranging from 0 to 5% are synthesized by a sol–gel processing technique. The structural and optical properties of ZnO and In–ZO nanoparticles are characterized by different techniques. The structural study confirms the presence of hexagonal wurtzite phase and indicates the incorporation of In^(3+) ions at the Zn^(2+) sites. However, the optical study shows a high absorption in the UV range and an important reflectance in the visible range. The optical band gap of In–ZnO sample varies between 3.16 e V and 3.22 e V. The photoluminescence(PL) analysis reveals that two emission peaks appear: one is located at 381 nm corresponding to the near-band-edge(NBE) and the other is observed in the green region. The aim of this work is to study the effect of indium doping on the structural, morphological, and optical properties of ZnO nanoparticles.

Synthesis of ZnS nanoparticles by solid-liquid chemical reaction with ZnO and Na_2S under ultrasonic

A novel and simple solid-liquid chemical reaction route was proposed to synthesize ZnS nanoparticles.In the method,ZnS nanoparticles were prepared by reaction of ZnO and Na2S in water with ultrasonic radiation at low temperature.The effects of process parameters on the properties of ZnS particles were investigated.The products were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),transmission electron microscopy(TEM),infrared spectroscopy(IR),thermogravimetrydifferential thermogravimetry(TG-DTG)and fluorescence emission spectroscopy.The results show that these particles are good crystalline zinc blende with average size of 35 nm,and possess good IR transmittance in the range of 400 to 4 000 cm1and good thermal stability in oxygen.

Cu- and Ni-Doping Effect on Structure and Magnetic Properties of Fe-Doped ZnO Nanoparticles

Cu- and Ni-codoped FeZnO particles with the wurzite structure were successfully synthesized at low temperature by a co-precipitation method. The samples were characterized using a vibrating sample magnetometer, X-ray diffraction, energy dispersive X-ray spectroscopy, UV-Vis spectrophotometry and electron spin resonance. The results demonstrated that room temperature ferromagnetic order was observed in both samples and the magnetization was higher than that of Fe-doped ZnO. The correlation between the structural and magnetic properties is discussed.

Preparation of ZnO Nanoparticles from Zn-containing Rotary Hearth Furnace Dust

To solve the problem of the low added value Zn-containing rotary hearth furnace(RHF)dust,two deep eutectic solvents(DESs)were employed,such as choline chloride-urea(ChCl-urea)and choline chloride-oxalic acid dihydrate(CC-OA)solvent and Zn-containing RHF dust(water-washed)as the research target.Then,we prepared ZnO nanoparticles using two DESs or their combination,namely,ChCl-urea(Method A),CC-OA(Method B),first CC-OA and then ChCl-urea(Method B-A)and first ChCl-urea and then CCOA(Method A-B),respectively.The effects of these methods on the properties of as-obtained precursors and ZnO nanoparticles were investigated in detail.The results indicated that the precursor obtained by Method A was Zn_(4)CO_(3)(OH)_(6)·H_(2)O,and those by Methods B,B-A,and A-B were all ZnC_(2)O_(4)·2H_(2)O.Moreover,the decomposition steps of the last three methods were similar.The ZnO contents of 95.486%,99.768%,99.733%,and 99.76%were obtained by Methods A,B,B-A,and A-B,respectively.Methods A,B,and B-A led to the formation of spherical and agglomerated ZnO nanoparticles with normal size distributions,where Method B showed the best distribution with an average diameter 25 nm.The ZnO nanoparticles obtained by the Method A-B did not possess good properties.

Flower-like ZnO modified with BiOI nanoparticles as adsorption/catalytic bifunctional hosts for lithium–sulfur batteries

Due to the high specific capacity and energy density, lithium–sulfur battery is regarded as a potential energy storage conversion system. However, the serious shuttle effect and the sluggish electrochemical reaction kinetics impede the practical use of lithium–sulfur battery. In the interests of breaking through the above knotty problems, herein we propose to use the polar flower-like Zn O modified by Bi OI nanoparticles as bifunctional host with catalytic and adsorption ability for polysulfides in lithium–sulfur battery.It can be found that this adsorption/catalytic host integrates the functions of adsorption and mutual catalytic conversion of polysulfides, in which the polar flower-like Zn O can effectively capture the polysulfides through strong polar-polar interaction, simultaneously the BiOI nanoparticles can accelerate the mutual conversion of polysulfides to Li2 S through reducing the activation energy and conversion energy barrier required for the electrochemical reaction. As a result, under a sulfur loading of 2.5 mg cm^(-2), the lithium–sulfur battery with Zn O/Bi OI/CNT/S as cathode reveals a considerable initial specific capacity of1267 mAh g^(-1) at a current density of 0.1 C. Even the current density increased to 1 C, the capacity can reach as 873.4 mAh g^(-1), together with a good capacity retention of 67.1% after 400 cycles. Therefore,after systematically study the positive effects of the flower-like ZnO modified by catalytic BiOI nanoparticles on the adsorption and catalytic conversion of polysulfides, this work provides a new idea for the development and application of high-performance lithium–sulfur batteries.

Synthesis of Niobium Doped ZnO Nanoparticles by Electrochemical Method: Characterization, Photodegradation of Indigo Carmine Dye and Antibacterial Study

Niobium doped Zincoxide nanoparticles has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, IR Spectroscopy, SEM, XRD, ICPMS and EDAX data. The UV-Visible spectroscopy result reveals that the band gap energy of ZnO/Nb2O5 nanoparticles to be 3.8 eV. The XRD results show that the crystallite size is to be 31.9 nm. The ICPMS data indicate the presence of 3,3461,328 counts of 93 Nb and 577,906,390 counts of 66 Zn. An improvement in the photocatalytic degradation of Indigocarmine dye (IC) in comparison to commercially available pure ZnO was observed. The photodegradation efficiency for ZnO/Nb2O5 and ZnO were found to be 97.4% and 52.1% respectively. The enhancement in photocatalytic activity of ZnO/ Nb2O5 was ascribed to the extended light absorption range and suppression of electron hole pair recombination upon Nb loading. The antibacterial activity of ZnO/Nb2O5 nanoparticles was investigated. These particles were shown to have an effective bactericide.

Preparation of homogeneous ZnO nanoparticles via precipitation-pyrolysis with Zn_5(CO_3)_2(OH)_6 as precursor

ZnO nanoparticles were synthesized via precipitation-pyrolysis (P&P), where the precursor zinc hydroxide carbonate (Zn5(CO3)2(OH)6) was obtained and then pyrolyzed. The results of TEM indicate that pyrolysis temperature is the predominant factor for controlling mean sizes of nanoparticles, ranging from 8 nm to 80 nm. Increasing the pyrolysis temperature enhances the mean size. The results of XRD show that nanoparticles are all of crystalline zincite. The mean size observed by TEM is in agreement with that calculated from the specific surface area(SSA) and the crystalline size calculated from the XRD patterns, indicating that the primary particles are rather uniform in size and have single crystals. The growth behaviors of epitaxy along the C-axis are responsible for the morphology of ZnO changing from sphere to rod-like shape, and then to reticulation. Compared with other synthesis approaches, P&P can get fairly good product with a relatively low cost.

Synthesis of ZnO doped ceria nanoparticles via azeotropic distillation processing

The synthesis of nano-sized ZnO-doped CeO2 of 20 nm in crystal size by a coprecipitation technique was investigated by different scanning calorimetries/thermalgravimetrics(DSC/TG), X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet (UV) absorbance. Azeotropic distillation processing was performed to effectively eliminate the residual water inside the as-prepared precipitate. Doping of ZnO results in the formation of solid solution. The crystal size of the nanoparticles increases with the increase of the doped ZnO amount, the calcination temperature and time. Doped CeO2 nanoparticles show excellent visible-light property and ultraviolet-absorption activity. Doping of ZnO doesn’t not weaken the UV-shielding property of ceria.

The co-transport of Cd(Ⅱ) and nZnO in saturated soil packed column:effects of ionic strength and pH

The rapid development and widespread use of ZnO nanoparticles(nZnO) in various industries have raised concerns about their potential environmental impact.Therefore,understanding the fate and role of nZnO in the natural environment is crucial for mitigating their hazardous effects on the environment and human safety.The purpose of the present study was to provide scientific support for understanding and eliminating the joint risk of nanoparticle and heavy metal pollution in the soil environment by revealing the co-transport characteristics of Cd(Ⅱ) and ZnO nanoparticles(nZnO) in soil under different ionic strength(IS) and pH.The impacts of different IS and pH on the co-transport of Cd(Ⅱ) and nZnO in a20 cm long with an inner diameter of 2.5 cm acrylic column packed with 10 cm high soil samples were investigated in the present study.In the above system,a500 μg L^(-1) Cd(Ⅱ) loaded nZnO suspension pulse with varying IS or pH was introduced into the soil column for leaching over 5 PVs,followed up by 5 PVs background solutions without nZnO.The IS was 1,10,or 50 mM NaCl,with pH6,or the pH was 6,7 or 8 with 1 mM NaCl.Meanwhile,Sedimentation experiments for nZnO,adsorption of Cd(Ⅱ) on soil,and nZnO,DLVO theory calculation for the same background condition were conducted.The presence of nZnO significantly increased the mobility of Cd(Ⅱ) as a result of its strong adsorption capacity for nZnO-associated Cd(Ⅱ).However,with the increase of IS,the co-transport of nZnO and Cd(Ⅱ) was decreased and the retention of nZnO in the soil column due to more nZnO attended to aggregate and sediment during the transport and the decrease in the adsorption capacity of nZnO for Cd(Ⅱ) by competition of Na^(+).When pH was 6,7,and 8,the co-transport of nZnO and Cd(Ⅱ) increased with higher pH due to the lower electrostatic attraction between nZnO and soil under higher pH.Meanwhile,the DLVO theory was fitted to describe the above co-transport process of nZnO and Cd(Ⅱ).More attention should be paid to the presence of nZnO on the migration of Cd(Ⅱ) in the natural soil to control the potential risk of nanoparticles and heavy metals to the environment.The risk of co-transport of nZnO and Cd(Ⅱ) might be controlled by adjusting IS and pH in the soil solution.

Erratum to “Indium doping effect on properties of ZnO nanoparticles synthesized by sol-gel method”

Figure 2 in our original paper [Chin. Phys. B 28 047701(2019)] was downloaded by default. We present the correct figure in this erratum.

Characteristics and Photoeatalytie Effects of Zn/ZnO Nanowhiskers Compared with ZnO Nanoparticles

ZnO nanopowders were prepared by oxidizing Zn vapor in the atmosphere of mixture gas of At and O2 at low pressure. Tetrapod nanowhiskers synthesized at a pressure of 1.6 kPa show pure ZnO feet and Zn phase in the core of the nanopowder. The ellipsoid ZnO nanoparticles were produced at the pressure of 10 kPa. The photodegradation rate of aniline and chemical oxygen demand removal demonstrate that the photocatalytic efficiency of Zn/ZnO nanowhiskers with UV irradiation is higher than that ofZnO nanoparticles. The tetrapod morphology and Zn phase inside nanowhiskers play key a role in photodegradation process.

Physiological Effects of MgO and ZnO Nanoparticles on the Citrus maxima

Toxicity of MgO and ZnO nanoparticles at concentrations of 250, 500 or 1 000 mg/L for Citrus maxima seedlings was investigated to evaluate the potentiality of their use as nano-fertilizers. Uptake and translocation of metal oxide nanoparticles and lipid peroxidation were measured and compared with those of plants exposed to the highest equivalent concentrations of Mg^(2+) and Zn^(2+). MgO nanoparticles were translocated from roots to shoots, while translocation of ZnO nanoparticles was low. Exposure to Mg^(2+) and MgO at all concentrations entailed severe toxicity and strong oxidative stress. ZnO nanoparticles showed only mild toxicity, while Zn^(2+) caused leaf vein chlorosis and strong oxidative stress to plant shoots. In conclusion, the toxicity of MgO nanoparticles to the plant resulted from the dissolved Mg^(2+) concentration, while that of ZnO nanoparticles was not correlated with the dissolved Zn^(2+) concentration. Our findings are significant for development and application of MgO and ZnO nanoparticles as nano-fertilizers in agriculture.

Preparation and UV-light Absorption Property of Oleic Acid Surface Modified ZnO Nanoparticles

Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, infrared spectroscopy（IR） and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.