Recent progress in zinc oxide nanomaterials and nanocomposites: From synthesis to applications

The global market of ZnO grows at an annual rate of 4.03%. ZnO has been used in a wide array of applications owing to its unique chemical, physical, and biological properties. In general, the properties of ZnO, such as band gap, crystallite size, and morphology, depend on the synthesis method and parameters employed. In this review, recent progress in the research on ZnO is presented. This review focuses on the latest advancements in pristine ZnO, doped ZnO, ZnO-based nanocomposites with other metal oxides, carbon-based materials, and spinels. The effect of the synthesis method and conditions on the properties of ZnO is discussed. In particular, recent studies on ZnO prepared through precipitation method, green synthesis, green combustion method, hydrothermal method, microwave-assisted hydrothermal, and sol–gel synthesis are reviewed. The effect of dopants and metal oxides on ZnO characteristics is also laid out. This review aims to provide the readers with a thorough understanding of structure–property relationships achieved by varying the synthesis parameters of ZnO, which will be beneficial for the fabrication of high-performance ZnO-based materials for photocatalytic, biological, gas sensing, and flexible electronic applications.     

金属氧化物一维纳米材料的制备及其应用

综述了利用阳极氧化铝模板制备金属氧化物一维纳米材料的方法及其在催化剂、光电器件等领域的应用情况,简要指出了尚需进一步研究的问题与发展趋势。     

Green synthesis of copper oxide nanoparticles: Characterization and applications for environmental and biomedical fields

In recent years, there has been an increasing interest in the development of plant-based nanoparticles due to their numerous benefits over conventional physio-chemical methods, including sustainability and environmental safety. Green synthesis, a process that produces safe and sustainable goods without the use of harsh chemicals or other harmful processes, is gaining popularity. The current study focuses on the green synthesis of copper oxide nanoparticles using Piper nigrum leaf extracts, their characterization, and applications. The synthesis of nanoparticles was confirmed by changes in colour, further endorsed by UV–visible spectroscopy. Copper oxide (CuO) nanoparticles were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). CuO nanoparticle sizes ranged between 58.23 and 69.89 nm and were spherical in shape. FTIR results indicated a functional group capped on the nanoparticle surface. The antibacterial activity of the copper oxide nanoparticles was tested, and they exhibited the significant decrease in bacterial concentration and the largest zone of inhibition, making them an efficient disinfectant. Antimicrobial activity against Bacillus subtilis and Escherichia coli was observed. Furthermore, the synthesized CuO nanoparticles exhibited a high affinity for safranin dyes and demonstrated maximum removal efficiency. This makes them an effective agent for removing dyes in wastewater from industries such as clothing manufacturing. Safranin dye was successfully removed with an efficiency of 78% using nanoparticles. In conclusion, the green synthesis of copper oxide nanoparticles using plant extracts presents an eco-friendly and sustainable approach for producing nanoparticles with a wide range of potential applications.     

Spherical silica micro/nanomaterials with hierarchical structures: synthesis and applications

This paper reviews the progress made recently in synthesis and applications of spherical silica micro/nanomaterials with multilevel (hierarchical) structures. The spherical silica micro/nanomaterials with hierarchical structures are classified into four main structural categories that include (1) hollow mesoporous spheres, (2) core-in-(hollow porous shell) spheres, (3) hollow spheres with multiple porous shells and (4) hierarchically porous spheres. Due to the complex structures and being focused on spherical silica micro/nanomaterials, some novel methods based on the combination of two routine methods or two surfactants, and some special synthetic strategies are proposed to produce the spherical silica micro/nanomaterials with hierarchical structures. Compared with the same-sized solid, porous or hollow silica spheres, these fantastic spherical silica micro/nanomaterials with hierarchical structures exhibit enhanced properties which may enable them to be used in broad and promising applications as ideal scaffolds (carriers) for biological, medical, and catalytic applications.     

纳米铁的绿色合成及其在环境中的应用研究进展

纳米铁（零价铁及铁氧化物）比表面积大、还原能力强、反应活性高,是一种良好的环境功能材料。传统的纳米铁合成方法中,物理方法对反应所需仪器设备要求较高,化学方法使用的还原剂具有毒性,绿色合成方法能够有效克服传统方法的不足之处。本文首先根据合成途径、纳米铁的类型介绍了利用植物和微生物对纳米零价铁（nZVI）及纳米铁氧化物（IONPs）进行绿色合成的方法,同时论述了制备的纳米铁所表现的特征（如形貌、尺寸、聚集倾向、等电位点）。随后总结了纳米铁通过不同反应机制（吸附、还原、催化氧化）去除环境有机、无机污染物（染料、芳香族化合物、硝酸盐、重金属）的应用。最后指出了纳米铁在绿色合成与实际应用过程中存在的挑战性问题及解决方法,以期为纳米铁今后的深入研究和大规模的工业生产应用提供参考依据。     

Greener synthesis and medical applications of metal oxide nanoparticles

Over the past decade, the subject of “greener chemistry" and chemical processes has been emphasized. The “greener chemistry” improves environmental efficiency in reducing the consumption of resources and energy and achieving a stable economic development of the environment. Nanotechnology is investigating nanoscale materials that have applications in the area of biotechnology and nanomedicine alongside several other significant applications such as cosmetics, drug delivery, and biosensors. The different shapes and sizes of nanoparticles can be synthesized with physical, chemical, or biological methods. The tendency to produce nanomaterials, especially metal oxides, and use them, is increasing because of their exciting properties in the nanoscale. However, metal oxide nanoparticles produced by chemical methods have significant concerns due to hazardous and toxic chemicals and their environmental damage. The production of metal oxide nanoparticles using the principles of greener chemistry has found a special place in research. Increased awareness of greener chemistry and biological processes has necessitated using environmentally friendly methods for the production of non-toxic nanomaterials. Plants and polymeric materials as renewable and inexpensive sources have received particular attention to prepare nano biomaterials. The use of plants to synthesize metal oxide nanoparticles because of the non-use toxic pollutants is one of the environmentally friendly methods, and that's why this type of synthesis is called greener synthesis. In this review, we exhibit a total sight of greener synthesis methods for producing metal oxide nanoparticles and their medical applications.     

A general strategy for synthesis of metal oxide nanoparticles attached on carbon nanomaterials

We report a general strategy for synthesis of a large variety of metal oxide nanoparticles on different carbon nanomaterials (CNMs), including single-walled carbon nanotubes, multi-walled carbon nanotubes, and a few-layer graphene. The approach was based on the π-π interaction between CNMs and modified aromatic organic ligands, which acted as bridges connecting metal ions and CNMs. Our methods can be applicable for a large variety of metal ions, thus offering a great potential application.     

Aptamer-conjugated nanomaterials for bioanalysis and biotechnology applications

In recent years, nanomaterials have captured the attention of scientists from a wide spectrum of domains. With their unique properties, nanomaterials offer great promise for numerous applications, ranging from catalysis to energy harvesting and information technology. Functionalized with the desired biomolecules, nanomaterials can also be utilized for many biomedical applications. This paper summarizes recent achievements in the use of aptamer-conjugated nanomaterials for bioanalysis and biotechnology applications. First, we discuss the features and properties of aptamers and then illustrate the use of aptamer-conjugated nanomaterials as sensing platforms and delivery vehicles, emphasizing how such integration can result in enhanced sensitivity and selectivity.     

Hetero-structured semiconductor nanomaterials for photocatalytic applications

Photocatalyst represents alternative solutions for renewable energy generation and environmental remediation. For photocatalytic applications, semiconductor nanomaterials emerge as important materials due to their unique structures, chemical and physical properties. Herein, we illustrate a brief overview of the recent progress in the development of hetero-structure nanomaterial based photocatalysts. Particularly, we focus our discussions on various dimensional (0D, 1D, 2D, and 3D) hetero-nanostructure of semiconductors to solve essential problems that are visible light absorption, fast charge separation, effective cocatalyst for charge utilization, and photoelectrochemical stability.     

三维金属氧化物纳米材料的研究进展

三维金属氧化物纳米材料（3D-MONs）具有独特的连续多孔网络结构特点,不仅使其保留了金属氧化物特有的化学性质,而且表现出低密度、高比表面积、高孔隙率、低热导率等优异的物理性能,是近年来纳米材料领域一个新的研究热点。综述了3D-MONs制备方法的研究进展,重点介绍了水热合成法、溶胶-凝胶法、模板法、溶液喷射法、直接发泡法,并对其共性与差异进行了讨论;探讨了3D-MONs在污水治理、空气净化、储能、隔热领域应用的研究进展;在此基础上,提出了合成3D-MONs需要解决的问题及其应用展望。     

超顺磁性Fe_3O_4纳米粒子化学合成及生物医学应用进展

综述了超顺磁性氧化铁纳米粒子合成方法和在生物医学领域中的研究进展,重点讨论了目前比较常用的化学合成方法对Fe3O4纳米粒子性能的影响,比较了各种方法的优劣,在此基础上,概述了超顺磁性Fe3O4纳米粒子在核磁共振成像、磁性靶向给药、磁性分离等方面的应用。通过综述,可望获得对Fe3O4纳米粒子的化学合成方法和生物医学应用的全面了解。     

超顺磁性Fe_3O_4纳米粒子化学合成及生物医学应用进展

综述了超顺磁性氧化铁纳米粒子合成方法和在生物医学领域中的研究进展,重点讨论了目前比较常用的化学合成方法对Fe3O4纳米粒子性能的影响,比较了各种方法的优劣,在此基础上,概述了超顺磁性Fe3O4纳米粒子在核磁共振成像、磁性靶向给药、磁性分离等方面的应用。通过综述,可望获得对Fe3O4纳米粒子的化学合成方法和生物医学应用的全面了解。     

One-dimensional electrospun ceramic nanomaterials and their sensing applications

One-dimensional sensing materials that are prepared via electrospinning and controlled annealing exhibit intrinsic properties, such as electron transmissivity, magnetic susceptibility, specific heat capacity, as well as optical and mechanical characteristics. Particularly, the electronic transmission characteristics of the ceramic fiber materials, such as the electrical conductivity, photocurrent, magnetoresistance, nanocontact resistance, and dielectric properties, exhibited great potential for applications in the next generation of electronic sensing devices. First, electrospun ceramic materials with different structural and functional characteristics were reviewed here, after which the strategies for improving their properties, as well as the method for assembling the flexible devices, are summarized. Moreover, the electrospun ceramic nanofibers were detailedly discussed regarding applications in device construction and wearable electronics, such as photosensors, gas sensors, mechanical sensors, and other energy storage devices. Finally, the future development direction of the electrospinning technology for multifunctional and wearable electronics skin was proposed.     

纳米四氧化三铁的化学制备方法研究进展

阐述了纳米四氧化三铁在磁性材料、多功能材料、催化材料以及医学领域的应用现状。对纳米四氧化三铁的制备方法如沉淀法、溶胶-凝胶法、微乳液法、水热与溶剂热法、热分解法、静电纺丝法等做了介绍。分析了各种纳米四氧化三铁材料的形态如纳米颗粒、纳米棒、纳米线、纳米膜、杂化、核壳结构纳米晶等的适用领域。总结了各种制备方法的研究进展,分析了其优缺点并结合作者课题组在纳米四氧化三铁制备方面的研究工作,对纳米四氧化三铁的今后的研究方向作了展望：制备特殊形貌的纳米四氧化三铁材料、减少纳米四氧化三铁的团聚和氧化、多种制备方法的结合以及如何实现大规模工业化生产。     

Green nickel/nickel oxide nanoparticles for prospective antibacterial and environmental remediation applications

The extensive use of broad-spectrum antibiotics has resulted in antibiotic resistance for many human pathogenic bacteria making multi-drug resistance an increasing issue in the management of various infectious diseases. The current research focused on the green synthesis of nickel/nickel oxide nanoparticles (Ni^o/NiO nanoparticles) using seeds extract of Lactuca Serriola, bactericidal effect on human pathogenic bacteria and the photocatalytic activity. Highly crystalline nature of Ni^o/NiO nanoparticles was confirmed by X-ray diffraction (XRD). Infrared spectra of seeds extract of Lactuca Serriola (LS) evidenced the presence of many functional groups of phytochemicals acting as reducing or capping agents. From field emission scanning electron microscopic (FESEM) images of Ni^o/NiO nanoparticles, it was clearly observed that the particles were slightly spherical in shape with size <100 nm. The Ni^o/NiO nanoparticles were also tested against eight pathogenic bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Basilus subtilis, Basilus pumilus, Micrococcus luteus, E. coli and Bordetella bronchiseptica) which displayed significant antibacterial activity at low doses and almost complete inhibition at optimized concentration. From the bandgap study, the reduced bandgap energy value of 1.57 eV indicated its potential semiconductor photocatalytic behavior. Higher degradation efficiency against the model contaminant crystal violet dye, possibility of multiple degradation mechanisms and simple recovery suggested that the green synthesized Ni^o/NiO nanoparticles might be best suitable candidates for environmental remediation applications.     

超声化学法在纳米材料制备中的应用及其进展

介绍了运用超声化学法制备纳米材料的基本原理及其相对于其它传统的方法所具有的优势,综述了超声化学沉淀法、超声喷雾热分解法和超声电化学法等在纳米材料制备中的应用及其进展。最后对超声化学法制备纳米材料的发展方向提出了展望。     

超临界连续水热法制备无机纳米材料

介绍了超临界连续水热法用于制备无机纳米材料近年来所取得的研究成果。主要介绍了此方法在反应器设计、掺杂型纳米材料的制备及纳米材料的原位改性3方面的研究进展,并对未来的发展进行了展望。