Influence of inorganic oxidants and metal ions on photocatalytic activity of prepared zinc oxide nanocrystals

Zinc oxide nanocrystals were prepared by precipitation method using ZnSO4.7H2O and NaOH as raw materials. The prepared ZnO nanocrystals were characterized by powder X-ray diffraction (XRD). Primary objective was to focus on the influence of inorganic oxidants, metal ions and anions on photocatalytic activity of prepared ZnO nanocrystals. The study on the effects of oxidants such as IO−4 , 2 S2O8− , BrO3− and ClO3− reveal that periodate ion is more efficient than others in improving the photocatalytic properties of ZnO nanocrystals. An investigation on the influence of metal ions on photocatalytic activity reveals that the removal of pollutant increases in the presence of Fe3+ and Cu2+. But negative effects are observed in the presence of anions. The possible roles of the additives on the reaction and the possible mechanisms of effect were discussed. The quantum yield ( ϕ ) and electrical energy per order (EEO) were estimated and compared for UV/ZnO/Oxidant catalytic system.

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Innovative Low-Cost Carbon/ZnO Hybrid Materials with Enhanced Photocatalytic Activity towards Organic Pollutant Dyes’ Removal

Nanomaterials ◽

10.3390/nano10091873 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1873

Author(s):

Petronela Pascariu ◽

Niculae Olaru ◽

Aurelian Rotaru ◽

Anton Airinei

Keyword(s):

Photocatalytic Activity ◽

Hybrid Materials ◽

Raw Materials ◽

Structural Characteristics ◽

Low Cost ◽

Organic Pollutant ◽

Zno Nanostructures ◽

Zno Nanocrystals ◽

Electrospinning Method ◽

New Type

A new type of material based on carbon/ZnO nanostructures that possesses both adsorption and photocatalytic properties was obtained in three stages: cellulose acetate butyrate (CAB) microfiber mats prepared by the electrospinning method, ZnO nanostructures growth by dipping and hydrothermal methods, and finally thermal calcination at 600 °C in N2 for 30 min. X-ray diffraction (XRD) confirmed the structural characteristics. It was found that ZnO possesses a hexagonal wurtzite crystalline structure. The ZnO nanocrystals with star-like and nanorod shapes were evidenced by scanning electron microscopy (SEM) measurements. A significant decrease in Eg value was found for carbon/ZnO hybrid materials (2.51 eV) as compared to ZnO nanostructures (3.21 eV). The photocatalytic activity was evaluated by studying the degradation of three dyes, Methylene Blue (MB), Rhodamine B (RhB) and Congo Red (CR) under visible-light irradiation. Therefore, the maximum color removal efficiency (both adsorption and photocatalytic processes) was: 97.97% of MB (C0 = 10 mg/L), 98.34% of RhB (C0 = 5 mg/L), and 91.93% of CR (C0 = 10 mg/L). Moreover, the value of the rate constant (k) was found to be 0.29 × 10−2 min−1. The novelty of this study relies on obtaining new photocatalysts based on carbon/ZnO using cheap and accessible raw materials, and low-cost preparation techniques.

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Effect of Substituents on the Electrochemical Reversible Discharge Capacity of Cobalt Hydroxide Electrodes

Journal of New Materials for Electrochemical Systems ◽

10.14447/jnmes.v18i2.375 ◽

2015 ◽

Vol 18 (2) ◽

pp. 091-093 ◽

Cited By ~ 1

Author(s):

Thimmasandra Narayan Ramesh

Keyword(s):

Zinc Oxide ◽

Metal Ions ◽

Discharge Capacity ◽

Electrode Material ◽

Nickel Hydroxide ◽

Precipitation Method ◽

Cobalt Hydroxide ◽

Effect Of Substituents ◽

Pure Cobalt ◽

Biphasic Mixture

Cobalt hydroxide, nickel hydroxide-cobalt hydroxide and zinc oxide-cobalt hydroxide biphasic mixtures were prepared by precipitation method. In spite of structural similarities exhibited by nickel hydroxide and cobalt hydroxide samples, former is a good electrode material and exchanges 1e-/Ni while latter does not show any reversibility. Presence of small amount of other metal ions such as nickel or zinc in the lattice of cobalt hydroxide or as a biphasic mixture of cobalt hydroxide-nickel hydroxide/cobalt hydroxide- zinc oxide, exchange up to 0.2 to 0.24e- exchange compared to pure cobalt hydroxide which shows 0.1 e- exchange.

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Preparation BiTaO4 by Precipitation Method and its Visible-Light Photocatalytic Activity

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.178-181.535 ◽

2012 ◽

Vol 178-181 ◽

pp. 535-538

Author(s):

Jing Jiao Zhang ◽

Pei Song Tang

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Diffuse Reflectance Spectroscopy ◽

Raw Materials ◽

Average Particle Size ◽

Precipitation Method ◽

Precipitation Process ◽

Average Particle ◽

X Ray Diffraction ◽

Uv Visible

The single phase BiTaO4was synthesized using Ta2O5and Bi(NO3)3as main raw materials by precipitation process. The products were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that BiTaO4was triclinic crystal with average particle size 100nm, and a band gap of about 2.77 eV. The photocatalytic experiment of BiTaO4shows the good photocatalytic activity for the decomposition of methylene blue under visible-light irradiation.

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Visible-Light Photocatalytic Activity of Fe and/or Ni Doped Ilmenite Derived-Titanium Dioxide Nanoparticles

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2019.16123 ◽

2019 ◽

Vol 19 (6) ◽

pp. 3343-3355 ◽

Cited By ~ 2

Author(s):

Ge Li ◽

Bao-Dong Wang ◽

Qi Sun ◽

Wayne-Qiang Xu ◽

Yi-Fan Han

Keyword(s):

Methylene Blue ◽

Photocatalytic Activity ◽

Visible Light ◽

Metal Ions ◽

Photocatalytic Performance ◽

Synergistic Effects ◽

Degradation Mechanism ◽

Photocatalytic Decomposition ◽

Precipitation Method ◽

Single Type

Pure TiO2 nanoparticles and ones doped with Fe and/or Ni were successfully prepared by a co-precipitation method from ilmenite. The samples were structurally characterized by XRD, XPS, FT-IR, UV-vis, SEM, EDX, AAS and BET measurement. The XRD results showed that all samples were anatase TiO2, and no characteristic peaks of dopants were observed. The crystallite sizes of all doped TiO2 nanoparticles were less than 20 nm and doping TiO2 with metal ions can suppress the crystal growth of the particles. The XRD and XPS results indicated that TiO2 was uniformly doped and its crystalline phase was not changed by doping. The specific surface area of Fe–Ni/TiO2 is bigger than that of the un-doped TiO2. The pore size and pore volume of Fe–Ni/TiO2 is smaller than that of the un-doped. UV-vis spectra of the samples showed that the absorption edge red shifted with increasing doped metal content. The photocatalytic activity was evaluated in oxidative degradation of methylene blue (MB) with H2O2 under visible light irradiation. When doped with a single type of transition metal, the photocatalytic performance of Ni-doped samples was lower than that of Fe-doped ones. For the co-doped catalysts, the catalytic efficiency of 0.5%Fe4%Ni/TiO2 was the highest, reaching 93.34% after 250 min. Metal doping enhanced the photocatalytic decomposition of methylene blue compared with that of pure TiO2 by up to 1.5 times. The synergistic effects of the two metal ions improved the photocatalytic performance. The particles exhibited pronounced activity in degradation of MB as well as efficient recyclability. The photocatalytic degradation mechanism of methylene blue was analyzed.

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Effect of Ag/ZnO-Graphitic Carbon Nitride on Antimicrobial Activity under Visible Light

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.858.116 ◽

2020 ◽

Vol 858 ◽

pp. 116-121

Author(s):

Sirirat Rodmuang ◽

Raweewan Plairaharn ◽

Kanokwan Teingtum ◽

Suntree Sangjan ◽

Orawan Chunhachart

Keyword(s):

Antimicrobial Activity ◽

Zinc Oxide ◽

Photocatalytic Activity ◽

Visible Light ◽

Carbon Nitride ◽

Dye Degradation ◽

Reduction Rate ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

Precipitation Method

Zinc oxide-graphitic carbon nitride (ZnO/g-C3N4) composites were synthesized by precipitation method in order to improve photocatalytic activity under visible light. To enhance antimicrobial activity, silver was added into zinc oxide-graphitic carbon nitride (Ag/ZnO/g-C3N4). Ultrastructures of the composite were analyzed by X-ray diffractometry (XRD) and transmission electron microscopy (TEM). Photocatalytic activity of the composites was carried out by degradation of methylene blue solution as a function of contact time. The results revealed that ZnO/g-C3N4 was capable of dye degradation at 96.65%. Addition of Ag into ZnO/g-C3N4 resulted in increase of dye reduction rate. For antibacterial test, Ag/ZnO/g-C3N4 exhibited bactericidal activity against Pseudomonas aeruginosa and Bacillus cereus. For antifungal test, Ag/ZnO/g-C3N4 showed resistance to Aspergillusniger for 7 days. Ag/ZnO-g-C3N4 composite exhibited better photocatalytic and antimicrobial activities compare to ZnO and g-C3N4. These results indicate that precipitation method is a cheap, rapid and efficient method that can be used to synthesize Ag/ZnO-g-C3N4 composites. For further studies, applications of this Ag/ZnO-g-C3N4 composites in microbiological and agricultural fields will be carried out.

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Zinc Oxide Nanoparticles for Water Purification

Materials ◽

10.3390/ma14164747 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4747

Author(s):

Angela Spoială ◽

Cornelia-Ioana Ilie ◽

Roxana-Doina Trușcă ◽

Ovidiu-Cristian Oprea ◽

Vasile-Adrian Surdu ◽

...

Keyword(s):

Electron Microscopy ◽

Zinc Oxide ◽

Photocatalytic Activity ◽

Zno Nanoparticles ◽

Zinc Oxide Nanoparticles ◽

Precipitation Method ◽

Oxide Nanoparticles ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

In this study, zinc oxide nanoparticles were synthesized through a simple co-precipitation method starting from zinc acetate dihydrate and sodium hydroxide as reactants. The as-obtained ZnO nanoparticles were morphologically and structurally characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photocatalytic activity, and by determining the antimicrobial activity against Gram-negative and Gram-positive bacteria. The XRD pattern of the zinc oxide nanoparticles showed the wurtzite hexagonal structure, and its purity highlighted that the crystallinity correlated with the presence of a single product, zinc oxide. The ZnO nanoparticles have an average crystallite size of 19 ± 11 nm, which is in accordance with the microscopic data. ZnO nanoparticles were tested against methyl orange, used as a model pollutant, and it was found that they exhibit strong photocatalytic activity against this dye. The antibacterial activity of ZnO nanoparticles was tested against Gram-negative and Gram-positive strains (Escherichia coli, Staphylococcus aureus, and Candida albicans). The strongest activity was found against Gram-positive bacteria (S. aureus).

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Visible light driven photocatalytic activity of Fe-doped ZnO nanocrystals

Functional Materials Letters ◽

10.1142/s1793604717500023 ◽

2017 ◽

Vol 10 (02) ◽

pp. 1750002 ◽

Cited By ~ 7

Author(s):

Bao-Gai Zhai ◽

Long Yang ◽

Qing-Lan Ma ◽

Yuan Ming Huang

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Density Functional ◽

Diffuse Reflectance Spectroscopy ◽

Deep Trap ◽

Precipitation Method ◽

Trap Level ◽

Zno Nanocrystals ◽

Visible Light Driven ◽

Doped Zno

Fe-doped ZnO nanocrystals at the level of 8[Formula: see text]mol% were synthesized via the co-precipitation method and then characterized by transmission electron microscopy, X-ray diffraction, diffuse reflectance spectroscopy and UV–Vis absorption spectroscopy. Strong absorptions with its peak at around 500[Formula: see text]nm were recorded in the range of 400–600[Formula: see text]nm for Fe-doped ZnO nanocrystals. Visible-light driven photocatalytic activity of Fe-doped ZnO nanocrystals was demonstrated via the photocatalytic degradation of methyl orange dye. Density functional calculations show that Fe dopant can generate a deep trap level at Ev [Formula: see text] 1.01[Formula: see text]eV in the bandgap of ZnO, which is believed to be responsible for the visible light responsive photocatalytic activity of Fe-doped ZnO.

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Zinc oxide nanoparticles help to enhance plant growth and alleviate abiotic stress: A review

Current Protein and Peptide Science ◽

10.2174/1389203721666201016144848 ◽

2020 ◽

Vol 21 ◽

Author(s):

Mohammad Faizan ◽

Fangyuan Yu ◽

Chen Chen ◽

Ahmad Faraz ◽

Shamsul Hayat

Keyword(s):

Zinc Oxide ◽

Plant Growth ◽

Abiotic Stresses ◽

Zinc Oxide Nanoparticles ◽

Growth And Yield ◽

Oxide Nanoparticles ◽

Main Concern ◽

Negative Effects ◽

Zno Nps ◽

Agricultural Yield

: Abiotic stresses arising from atmosphere change belie plant growth and yield, leading to food reduction. The cultivation of a large number of crops in the contaminated environment is a main concern of environmentalists in the present time. To get food safety, a highly developed nanotechnology is a useful tool for promoting food production and assuring sustainability. Nanotechnology helps to better production in agriculture by promoting the efficiency of inputs and reducing relevant losses. This review examines the research performed in the past to show how zinc oxide nanoparticles (ZnO-NPs) are influencing the negative effects of abiotic stresses. Application of ZnO-NPs is one of the most effectual options for considerable enhancement of agricultural yield globally under stressful conditions. ZnO-NPs can transform the agricultural and food industry with the help of several innovative tools in reversing oxidative stress symptoms induced by abiotic stresses. In addition, the effect of ZnO-NPs on physiological, biochemical, and antioxidative activities in various plants have also been examined properly. This review summarizes the current understanding and the future possibilities of plant-ZnO-NPs research.

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