Progress on Transition Metal-Doped ZnO Nanoparticles and Its Application

Singh, Pushpendra; Kumar, Ranveer; Singh, Rajan Kumar

doi:10.1021/acs.iecr.9b01561

Cited by 175 publications

(80 citation statements)

References 355 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[ 134–139 ] From all the aforementioned classes of metals, the dopants with comparable ionic size and highly soluble feature offers a vast variety of doping element options in MOs. [ 140 ] For example, Ye et al designed a binder‐free Co‐doped Ni(OH) 2 /Ni 3 S 2 hybrid cathode which delivered an ultrahigh specific capacitance value of 3023.4 F g −1 at 1 A g −1 and a superb rate performance. [ 141 ] Jampani et al developed Ti‐doped VO 2 via chemical vapor deposition (CVD) technique.…”

Section: Heterogeneous Ion Doping Strategymentioning

confidence: 99%

Oxygen Defects in Promoting the Electrochemical Performance of Metal Oxides for Supercapacitors: Recent Advances and Challenges

et al. 2020

View full text Add to dashboard Cite

and considered as indispensable energy storage devices because of their higher power density and greater life expectancy compared with their competitive counterparts such as batteries, fuel cells, and conventional capacitors. Significantly, owing to their distinct advantages including the simple and safe configuration, quick charge/discharge response, large power output, and long operating life (>100 000 cycles), SCs show a promising prospect in next-generation energy technologies, like smart and wearable electronics, quick charging cellphones, regenerative braking electric motors, and instant management of industrial power and energy. [20][21][22][23][24] Currently, there are three main categories of active materials employed to advance the electrochemical performance of SCs: i) carbonaceous matrix, ii) conducting polymers, and iii) metal oxides (MOs). With respect to the former two types, MOs, especially transition MOs, usually delivers a much higher specific capacitance, as their unique crystal structure, combined with the multiple oxidation states of metal ions, are both in favor of excellent charge storage capability. Sometimes, SCs assembled with MOs are also called pseudocapacitors (PCs), because different from carbon-based electrical double layer capacitors (EDLCs), they realize the charge storage via fast Faradaic redox and/or metal ion intercalation reactions. In this way, they could deliver substantially superior specific capacitances as high as 300-1200 F g −1 and offer 10-100 times larger energy density than that of EDLCs. [25][26][27][28][29] In recent years, various MO materials have been proposed as high-performance SCs electrodes, some of which the theoretical capacitances and common operating potential windows are summarized in Figure 1a,b. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Nevertheless, further practical applications of these SCs are severely hindered by the poor electrical conductivity and frustrating structural stability of semiconductive MOs. To address these issues, owing to the rapid advancement of nanotechnology, a series of nano-and meso-scale morphological engineering strategies have been proposed to boost the electrochemical performance of MOs, either by enlarging the electrochemical active surface area or by shortening the diffusion length of electrons/ions. [30][31][32] For instance, combining MOs with some other highly conductive substances such as carbonaceous materials and metals is validated to be a feasible Metal oxides (MOs) with multiple active sites are regarded as one of the most potential active materials for high-performance supercapacitor (SC) constructions. Engineering oxygen vacancies into MOs can effectively modulate their electronic properties, subtly induce impurity states in their bandgaps, and considerably optimize their electrical conductivity. Benefiting from these advantageous properties, the resultant oxygen-defective electrodes generally embed more electrochemical active sites and present better charge storage capability in co...

show abstract

Section: Heterogeneous Ion Doping Strategymentioning

confidence: 99%

Oxygen Defects in Promoting the Electrochemical Performance of Metal Oxides for Supercapacitors: Recent Advances and Challenges

et al. 2020

View full text Add to dashboard Cite

show abstract

“…(a) (b) Noble metals, such as Ag, Au, and Pd [60][61][62][63], and transition metals (e.g., Fe, Mn, Ni and Cu) [64][65][66] can be used to dope ZnO for improving its visible-light photocatalytic activity and reducing charge carrier recombination. In the case of noble metals, the formation of a Schottky junction at the metal-ZnO interface promotes electron-hole pair separation, thereby reducing charge recombination, and enhancing spectral response in the visible region ( Figure 6a) [61,67].…”

Section: Photocatalytic Ros Productionmentioning

confidence: 99%

Interactions of Zinc Oxide Nanostructures with Mammalian Cells: Cytotoxicity and Photocatalytic Toxicity

Liao

Jin

et al. 2020

IJMS

View full text Add to dashboard Cite

This article presents a state-of-the-art review and analysis of literature studies on the morphological structure, fabrication, cytotoxicity, and photocatalytic toxicity of zinc oxide nanostructures (nZnO) of mammalian cells. nZnO with different morphologies, e.g., quantum dots, nanoparticles, nanorods, and nanotetrapods are toxic to a wide variety of mammalian cell lines due to in vitro cell–material interactions. Several mechanisms responsible for in vitro cytotoxicity have been proposed. These include the penetration of nZnO into the cytoplasm, generating reactive oxygen species (ROS) that degrade mitochondrial function, induce endoplasmic reticulum stress, and damage deoxyribonucleic acid (DNA), lipid, and protein molecules. Otherwise, nZnO dissolve extracellularly into zinc ions and the subsequent diffusion of ions into the cytoplasm can create ROS. Furthermore, internalization of nZnO and localization in acidic lysosomes result in their dissolution into zinc ions, producing ROS too in cytoplasm. These ROS-mediated responses induce caspase-dependent apoptosis via the activation of B-cell lymphoma 2 (Bcl2), Bcl2-associated X protein (Bax), CCAAT/enhancer-binding protein homologous protein (chop), and phosphoprotein p53 gene expressions. In vivo studies on a mouse model reveal the adverse impacts of nZnO on internal organs through different administration routes. The administration of ZnO nanoparticles into mice via intraperitoneal instillation and intravenous injection facilitates their accumulation in target organs, such as the liver, spleen, and lung. ZnO is a semiconductor with a large bandgap showing photocatalytic behavior under ultraviolet (UV) light irradiation. As such, photogenerated electron–hole pairs react with adsorbed oxygen and water molecules to produce ROS. So, the ROS-mediated selective killing for human tumor cells is beneficial for cancer treatment in photodynamic therapy. The photoinduced effects of noble metal doped nZnO for creating ROS under UV and visible light for killing cancer cells are also addressed.

show abstract

“…Secondly, neither metallic Cu nor copper oxides (CuO and Cu 2 O) are ferromagnetic [14]. For these reasons, there is an opportunity to clarify the origin and the coupling mechanism of ferromagnetic behavior of diluted magnetic semiconductors, which are still under debate [2,15]. Upon this, much effort has been devoted to investigating Cu-doped ZnO systems.…”

Section: Introductionmentioning

confidence: 99%

Effects of Copper Dopants on the Magnetic Property of Lightly Cu-Doped ZnO Nanocrystals

et al. 2020

View full text Add to dashboard Cite

To explore the origin of magnetism, the effect of light Cu-doping on ferromagnetic and photoluminescence properties of ZnO nanocrystals was investigated. These Cu-doped ZnO nanocrystals were prepared using a facile solution method. The Cu2+ and Cu+ ions were incorporated into Zn sites, as revealed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). At the Cu concentration of 0.25 at.%, the saturated magnetization reached the maximum and then decreased with increasing Cu concentration. With increasing Cu concentration, the photoluminescence (PL) spectroscopy indicated the distribution of VO+ and VO++ vacancies nearly unchanged. These results indicate that Cu ions can enhance the long-range ferromagnetic ordering at an ultralow concentration, but antiferromagnetic “Cu+-Vo-Cu2+” couples may also be generated, even at a very low Cu-doping concentration.

show abstract

Progress on Transition Metal-Doped ZnO Nanoparticles and Its Application

Cited by 175 publications

References 355 publications

Oxygen Defects in Promoting the Electrochemical Performance of Metal Oxides for Supercapacitors: Recent Advances and Challenges

Oxygen Defects in Promoting the Electrochemical Performance of Metal Oxides for Supercapacitors: Recent Advances and Challenges

Interactions of Zinc Oxide Nanostructures with Mammalian Cells: Cytotoxicity and Photocatalytic Toxicity

Effects of Copper Dopants on the Magnetic Property of Lightly Cu-Doped ZnO Nanocrystals

Contact Info

Product

Resources

About