Aluminum Nitrate Research Articles

Agricultural bamboo leaf waste as carbon precursor for the preparation of Cu-Al/biomass fiber adsorption and its application in the removal of ammonia nitrogen pollutants from domestic wastewater

Biomass derived from the plant waste in the environment has been recognized as a potential source for preparing adsorbent in recent years. In this context, abandoned bamboo leaves from the surrounding area were collected and used as carbon precursor to prepare novel adsorbent for ammonia nitrogen removal. Bamboo leaves were treated with alkaline solution to produce biomass fiber (BF), then BF was reacted with aluminum nitrate nonahydrate and copper(ii) nitrate hydrate to form a Cu-Al composite oxide layer on the surface. Samples were well characterized by SEM, XRD and BET technique. The influencing factors including the pH, temperature, the time, and the dosage of adsorbent on the adsorption of ammonia nitrogen were studied. It was found that the maximum adsorption capacity toward ammonia nitrogen was fitted out to be 18.29 mg/g from the Langmuir isotherms model. In addition, the adsorbent showed outstanding total ammonia nitrogen removal in actual domestic sewage (Total ammonia nitrogen, TN, 12.6 ∼ 16.2 mg/L), which is significantly higher than that of the commercial activated carbon. Kinetics and thermodynamics studies indicated that the synergistic adsorption effect between biomass material and metal oxide plays a dominate role in the adsorption process. Therefore, the proposed strategy provides a promising way to deal with ammonia nitrogen wastewater and other types of water pollution. Besides, the reuse of surrounding plant waste is also consistent with the concept of green chemistry.

Fabrication and characterization of porous mullite ceramics with ultra-low shrinkage and high porosity via sol-gel and solid state reaction methods

Porous mullite ceramics with ultra-low shrinkage and high porosity were prepared by solid state reaction between MoO3 and mullite precursor powders which were synthesized from tetraethylorthosilicate and aluminium nitrate nonahydrate via sol-gel methods. The synthetic process of mullite precursor powder and effects of MoO3 amount on the phase composition, microstructure, physical properties such as firing shrinkage, open porosity, bending strength, water absorption and bulk density of porous mullite ceramics were investigated. The results indicated that the addition of MoO3 not only lowered the mullite forming temperature from 985.4 to 853.3 °C, but also restrained densification behavior of samples due to the formation of mullite and Al2O3–MoO3 solid solution, besides, MoO3 also improves the formability, open porosity and bending strength of samples. The optimal amounts of MoO3 is 8 wt%, and the resultant samples exhibit outstanding properties, including a low shrinkage rate of 1.86 ± 0.07%, an open porosity of 61.91 ± 0.16% and a bending strength of 9.35 ± 1.11 MPa.

Kinetic study of distillation and cracking of heavy oil on bimodal meso–macroporous materials of silica and aluminosilicate by thermogravimetry

Bimodal silica and aluminosilicate materials containing mesopores and macropores were synthesized by hydrothermal method using sodium silicate, aluminum nitrate, P123 triblock copolymer, n-decane, hydrochloric acid and water. The uncalcined silica compound was previously characterized by thermogravimetry, and the calcined materials were characterized by X-ray diffraction, infrared absorption spectroscopy, and scanning electron microscopy. The obtained materials have bimodal characteristics with mesopores and macropores in their structures, which pores are ideal for processing bulky molecules, such as hydrocarbons present in heavy oil. In this work, the synthesized silica and aluminosilicate were used as materials for distillation and cracking of a petroleum sample with oAPI = 17.4. The process was evaluated by thermogravimetry, in the temperature range from 25 to 900 °C, in a nitrogen atmosphere. The determination of activation energies (Ea) as a function of the degree of conversion was obtained by using the Ozawa–Flynn–Wall kinetic model and at heating rates of 5, 10 and 20 °C min−1. It was observed that the catalytic cracking of the oil presented Ea of 196 kJ mol−1 for 90% conversion. At the same conversion, for the oil containing 10% of Si-MBB catalyst, the Ea decreased to 170 kJ mol−1 and for AlSi-BMM, the Ea was 155 kJ mol−1, showing the efficiency of bimodal materials containing mesopores and macropores in its structure for processing of heavy oil.

Mechanical and Corrosion Studies of Friction Stir Welded Nano Al2O3 Reinforced Al-Mg Matrix Composites: RSM-ANN Modelling Approach

Nano aluminum oxide was prepared by the combustion method using aluminum nitrate as the oxidizer and urea as a fuel. Characterization of synthesized materials was performed using SEM (scanning electron microscope), powder XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), and TEM (transmission electron microscope). Al-Mg/Al2O3 (2, 4, 6, and 8 wt%) metal matrix nanocomposites were prepared by liquid metallurgy route-vertex technique. The homogeneous dispersion of nano Al2O3 particles in Al-Mg/Al2O3 metal matrix nanocomposites (MMNCs) was revealed from the field emission SEM analysis. The reinforcement particles present in the matrix were analyzed through energy-dispersive X-ray spectroscopy method. The properties (corrosion and mechanical) of the fabricated composites were evaluated. The mechanical and corrosion properties of the prepared nanocomposites initially increased and then decreased with the addition of nano Al2O3 particles in Al-Mg Matrix. The studies show that, the presence of 6 wt% of nano Al2O3 particles in the matrix improved the properties of other combinations of nano Al2O3 in the Al-Mg matrix material. Further, the Al-Mg/Al2O3 (6 wt%) MMNCs are joined by friction stir welding and evaluated for microstructural, mechanical, and corrosion properties. Al-Mg/Al2O3 MMNCs may find applications in the marine field. The response surface method (RSM) was used for the optimization of tensile strength, Young’s modulus, and microhardness of the synthesized material which resulted in a 95% of statistical confidence level. Artificial neural network (ANN) analysis was also carried out which perfectly predicted these two properties. The ANN model is optimized to obtain 99.9% accurate predictions by changing the number of neurons in the hidden layer.

New environmental selective micro-mesoporous carbonaceous sorbent for eliminating tobacco specific nitrosamines and lead ion

New selective carbonaceous sorbent is one-pot fabricated using microburst of bi-metal salts in order to eliminate carcinogens in environment. We used discarded cigarette butts as carbon source, aluminum nitrate and ferrous acetate as pore-forming agents to prepare the versatile sorbent with a developed porosity and the well-exposed metal oxides in order to replace zeolites for the selective adsorption in environment protection. Numerous finely divided porous particles endowed the composite a surface area of over 350 m2g-1, enabling it to be the best sorbent of tobacco specific nitrosamines (TSNA) to date in solution. It adsorbed 41% of TSNA among hundreds of components in tobacco extract solution or 142 mg g−1of 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK) in aqueous solution, and rapidly trapped Pb(Ⅱ) at the S/L of 0.2 within 10 min with a capacity of 153 mg g−1. Moreover, new sorbent could catalyze the degradation of NNK in mild conditions, which is rare but is very important for environmental protection.

Mechanism and Optimized Process Conditions of Forming One-Dimensional ZnO Nanorods with Al-Doping by Electrodeposition Method

Textured transparent conductive electrodes for thin-film solar cells have been considered as an effective route for enhancing sunlight harvest due to light trapping. Here, we report a self-assembling electrochemical approach for preparing Al-doped ZnO nanorod arrays (NRAs) as light-trapping electrodes from a mixed aqueous solution of zinc nitrate and aluminium nitrate. The mechanism and optimized process conditions of forming one-dimensional ZnO nanorods with Al-doping were systematically investigated. The results showed that Al atoms were successfully doped into ZnO crystal lattice, and the morphologies could be controlled by adjusting the Al3+/Zn2+ ratio in the precursors and deposition time. The Al-doped ZnO films grew into well-aligned hexagonal NRAs with c-axis perpendicular to the substrates and then transited into a mixture of nanosheets and nanorods with Al3+/Zn2+ ratio increasing. They exhibited good electrical conductivity with a sheet resistance of 68-167Ω/square and appropriate visible light transmittance of 61-82%. Taking into account of desired morphology and phase purity, as well as good electrical conductivity and optical transmittance, the optimal window of Al3+/Zn2+ ratio in the precursors was determined between 1 at% and 2 at% with applied potential of -1.5V, bath temperature of 80°C, and deposition time of about 30min. The electrodeposition method provides a facile and efficient route for obtaining large-area textured transparent electrodes at a low cost.

The use of metal nitrate-modified amorphous nano silica for synthesizing solid amine CO2 adsorbents with resistance to urea linkage formation

The formation of urea linkages is a limitation to the application of solid amine CO2 adsorbents. Therefore, the development of solid amine adsorbents with resistance to urea linkage formation has attracted much interest over the last 5 years. In this study, we developed a facile method for synthesizing solid amine adsorbents with effective resistance to urea linkage formation. For the first time, metal nitrates were used to modify amorphous nano SiO2 to support polyethyleneimine (PEI). Three metal nitrates were investigated: aluminum, magnesium, and zinc nitrates. A series of adsorbents were prepared by controlling the mass ratios of metal nitrates and nano SiO2. After 50 cycles of adsorption–desorption tests, adsorbing at 75 °C under 15 % CO2 balanced with N2 and desorbing at 130 °C under pure CO2, Al-20%@SiO2-PEI, Al-15%@SiO2-PEI, Al-10%@SiO2-PEI, Zn-10%@SiO2-PEI, and Mg-10%@SiO2-PEI lost only 2.6 %, 4.0 %, 5.2 %, 15.9 %, and 28.8 % of their original CO2 adsorption capacities, respectively. However, SiO2-PEI, calcined SiO2-PEI, and Al-5%@SiO2-PEI lost 42.9 %, 48.6 %, and 49.6 %, respectively. By combining the infrared spectra of all the adsorbents through cyclic adsorption–desorption tests, inhibitory effects on urea linkage formation were proven for Al-20%@SiO2-PEI, Al-15%@SiO2-PEI, Zn-10%@SiO2-PEI, and Mg-10%@SiO2-PEI, and especially for Al-10%@SiO2-PEI. Through a relatively comprehensive analysis, we found that a desirable amount of metal nitrates could modify nano SiO2 samples and their corresponding adsorbents possessed a stronger H2O binding ability at 130 °C. The retained H2O could act as an inhibiting agent for the inhibition of urea linkage formation.

Performance analysis and comparison of methyl-modified Al2O3/SiO2 xerogels fabricated by two methods

Abstract Two methyl-modified Al2O3/SiO2 xerogels, i. e. AIP-Al2O3/MSiO2 and ANN-Al2O3/MSiO2 xerogels, were prepared using aluminum isopropoxide and aluminum nitrate nonahydrate as the aluminum precursors, respectively. The appearance, density, viscosity, Gibbs activation energy for viscous flow and reaction rate constant of the sols were analyzed and compared. Their microstructures were characterized by means of powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and nitrogen adsorption–desorption measurements. The results show that the Al–O–Si bond is formed in the AIP-Al2O3/MSiO2 and ANN-Al2O3/MSiO2 xerogels. The ANN-Al2O3/MSiO2 sol has a smaller mean particle size and greater sol stability than the AIP-Al2O3/MSiO2 sol. Meanwhile, the ANN-Al2O3/MSiO2 xerogel has a smaller pore size and higher porosity. The total pore volume and specific surface area of the ANN-Al2O3/MSiO2 xerogel are 27.27% and 29.36% larger than those of the AIP-Al2O3/ MSiO2 sample, respectively. The saturated adsorption capacity of the ANN-Al2O3/MSiO2 xerogel to methylene blue is 7.15% larger than that of the AIP-Al2O3/MSiO2 xerogel.

Large-scale preparation of powder composites xNiO/(1-x)Al2O3 in reactions of solution combustion synthesis

The conditions for the production of composites by Solution Combustion Synthesis (SCS) from reaction solutions of aluminum and nickel nitrates of various concentrations with glycine have been studied. The concentration of reaction solutions increases the product yield and the productivity of SCS process. The effect of the presence of Al3+ cations in reaction solutions on the combustion reaction intensity reduction has been established. The SCS precursors contained metallic nickel, nickel oxide and amorphous alumina. The phase composition of the samples changed in the process of annealing: nickel oxidation, crystallization of γ-Al2O3 (600 °C) and formation of NiAl2O4 spinel (600–800 °C) were observed. The maximal specific surface area value recorded after annealing at 800 °C was 59–63 m2/g. In samples obtained with a lower fuel content, γ-Al2O3 or a mixture of γ-Al2O3 and NiAl2O4 crystallize on the surface of composite particles. The concentration of NiO on the surface of composites obtained from precursors synthesized from concentrated solutions at φ = 1.4 is close to the nominal composition.

Synthesis of alumina by microwave-assisted combustion method using low fuel content and its use as catalytic support for dry reforming of methane

Alumina powders with high specific surface area (>200 m2g-1) were obtained quickly, easily and using only aluminum nitrate and urea (as fuel) through the microwave-assisted combustion method applying low power (450 W) and low fuel content. The powders obtained were calcined at temperatures of 550, 750 and 950 °C. The X-ray diffraction and Fourrier Transform Infrared (FTIR) results indicate that γ-Al2O3 was formed at temperatures of 550 and 750 °C, while the α and γ phases were identified in calcined alumina at 950 °C. The increase in calcination temperature strongly influenced the specific surface area and the pore size distribution, however no effect on the pore diameter was observed. The Al2O3 powder calcined at 550 °C was evaluated as catalytic support due to its most appropriate textural properties. The catalyst Ni/Al2O3 (Ni-A550) was prepared by wet impregnation method and calcined at 550 °C/3 h. The physical-chemistry properties were evaluated by X-ray diffraction, temperature programmed reduction and scan electron microscopy techniques. The results show that the Ni-A550 have high conversion of CH4 and CO2 and good H2 yield using a gas hourly space velocity (GHSV) of 72 L g−1 h−1. Therefore, the synthesized Al2O3 presents as a potential catalytic support material.

Synthesis and characterization of γ-Al2O3 and α-Al2O3 nanoparticles using a facile, inexpensive auto-combustion approach

In the present work, we have developed a facile, inexpensive, auto-combustion method for the synthesis of γ-Al2O3 and α-Al2O3 nanoparticles. This was performed by employing aluminum nitrate as an oxidant and glycine as a fuel. The γ-Al2O3 and α-Al2O3 nanoparticles were obtained by calcination of the combusted products at 800 °C for 2 h and at 1000 °C for 1 h, respectively. The generated alumina nanoparticles were characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscope (FE-SEM), high-resolution transmission electron microscope (HRTEM), and thermal analyses (TG and DTA). The average crystallite sizes of γ-Al2O3 and α-Al2O3 nanoparticles were estimated to be 5.8 nm and 15 nm, respectively. The TEM results revealed that the prepared alumina nanostructures were of low agglomeration degree. The proposed method exhibited that the phases of the produced alumina nanoparticles could be carefully tuned by the adapted experimental conditions.

Alumina Support for Cobalt Catalyst in a Methane Dry Reforming Reaction: The Role of Water Content in a Solvent Medium

This study aimed to synthesize alumina from an inorganic aluminum nitrate precursor in various binary solvent systems of ethanol and water using the sol-gel self-assembly (SSA) method, employing a triblock copolymer, pluronic P123, as the pore-directing agent. The resulting materials were implemented as a support for the cobalt (Co) catalyst in a methane dry reforming (MDR) reaction at 1073 K under 1 atm. Regardless of the water percentage used in the support synthesis, the methane dry reforming reaction over Co catalysts on alumina supports showed the negligible change in conversion during the 12 h reaction. Moreover, there was evidence of large quantities of amorphous carbon and graphitic carbon on the spent catalyst surface. However, the low oxidation temperature of these deposited carbons could help maintain the balance between the carbon formation and the carbon elimination processes on the catalyst surface during the reforming reaction, hence prolonging the lifetime of the catalyst. The high conversion of methane (CH4) from 64.6% to 82.8% and carbon dioxide (CO2) from 70.7% to 86.6% for the MDR reaction over the as-prepared alumina-supported Co catalyst demonstrated a significant improvement in catalyst production for the MDR reaction from the viewpoint of large-scale applications.

Hydrothermal synthesis and characterization of nano-particles γ-Al2O3

The study of hydrothermal treatment on the phase formation and the crystallites of gamma-alumina (γ-Al2O3) was performed. Different reaction time and temperature of hydrothermal treatment were investigated. The preparation of γ-Al2O3 includes precipitation of aluminum nitrate nonahydrate by ammonia, aging, washing, transferred the gel into the hydrothermal reactor, drying, and calcination at 600 °C. The precipitation was stopped at pH equals 7.5. The reaction times of hydrothermal treatment were 1 – 2 hours, and the temperatures were 140 – 200 °C. X-Ray Diffraction analysis was used to investigate the phase formation and the particle size. The results show all the samples represented pure nano γ-Al2O3. The examination of hydrothermal treatment of y-Al2O3 reveals as the reaction time longer, the crystallite grows bigger, as well as the higher temperature applied. The smallest γ-Al2O3 obtained based on the Scherrer equation is 4 nm and the biggest is 6.5 nm. Interestingly, the peaks of the γ-Al2O3 prepared by hydrothermal treatment at the longest time and the highest temperature have shifted into a higher diffraction angle. In the case of this sample, the peaks shifted into a higher diffraction angle. That is means there is a change in the lattice structure of γ-Al2O3 probably was affected by the lattice of hydroxyl content.

Microstructure and electrical properties of 3Y‐TZP/Al2O3 composite obtained using the citrate gel method

Abstract3Y‐TZP sinters with 1, 5, 10, and 15 mol% of Al2O3 were prepared using two different procedures from a 3‐YSZ powder synthesized via the citrate process. In the first procedure, alumina was introduced during synthesis via the citrate method. In the second one, the 3‐YSZ powder was impregnated with aluminum nitrate. All samples were sintered at 1773 K. The prepared composites were evaluated in terms of their microstructure, chemical and phase composition, and electrical properties. The total conductivity of the 3Y‐TZP/Al2O3 composite material, which contained primarily the tetragonal phase, was found to increase with temperature, and to decrease for reduced concentrations of alumina in 3Y‐TZP. In the case of the samples which had alumina introduced via impregnation, its higher content was not associated with significantly lower electrical conductivity. These samples generally exhibited higher conductivity than the samples to which alumina had been added via chemical synthesis.

Solid-Phase Adsorption of Curcumin from Turmeric Extracts by Lamellar Solids and Magnesium Oxide and Hydroxide

Solid-phase extraction and solid-phase adsorption are currently convenient experimental techniques employed to the concentration and purification of secondary metabolites of plant, microbial, and fungal origin. The aim of this research article was the screening of the capacity by 16 solid sorbents including layered structures (hydrotalcites and zirconium phosphates), magnesium oxide and hydroxide, and the phyllosilicates talc and bentonite to selectively concentrate curcumin from raw extract solutions of turmeric, Curcuma longal. (Fam. Zingiberaceae). HPLC analysis, coupled to PDA detection, showed that, among the sorbents employed, magnesium oxide was the most effective one reaching a percentage of adsorption of 96.6%. Other solids able to concentrate curcumin on their surface in percentages varying from48.9 to 68.7% included the hydrotalcites magnesium aluminum hydroxy acetate, magnesium aluminum acetate, magnesium aluminum hydroxy chloride, and magnesium aluminum nitrate, and finally magnesium hydroxide (47.0%). We have finally shown that these sorbents can be readily recovered an recycled without significant losses of adsorption capacities. Although a similar procedure has been recently described using anthraquinones from laxative plants as substrates, the application of these supports for the extraction in the solid phase of curcumin as a representative compound of the diarylheptanoid family is reported herein for the first time in the literature.

Crystal Facet Engineering of Copper-Based Metal–Organic Frameworks with Inorganic Modulators

Manipulating the exposed facets of metal-organic frameworks (MOFs) is of importance toward understanding their facet-dependent property in a variety of applications. Herein, we apply a novel inorganic competitive coordination strategy to control the growth orientation of copper-based MOFs (HKUST-1, MOF-14, and Cu-MOF-74) without sacrificing the pore accessibility and crystallinity. Through monitoring the reactant composition, we find that the competitive coordination induced by the added aluminium nitrate mainly affects the crystal growth stage rather than the nucleation stage. The kinetic study further reveals that Al3+ competes with Cu2+ to coordinate with ligands, restraining the growth rate of certain facets and resulting in the orientated growth of copper-based MOFs. Compared to the reduced pore accessibility of HKUST-1 crystals modulated by the organic modulation method, Al3+-modulated HKUST-1 displays a much larger surface area (>2200 m2/g) and more accessible Cu active sites. Hydroxylation of toluene was utilized as a model reaction to investigate the facet-catalytic activity for as-synthesized HKUST-1. The selectivity of the preferred product cresol increases with the morphology transformation of HKUST-1 from octahedron to cube.

Synthesis and characterization of two-dimensional (2D) nanosheet zinc aluminum layered double hydroxide (Zn/Al LDH) via an alkali-free route

The effect of different molar ratios on the synthesis of zinc aluminium layered double hydroxide (Zn/Al LDH) via an alkali-free route was carried out in this research. This method was prepared by mixing zinc nitrate solution, aluminium nitrate solution, and ammonium carbonate solution at a constant pH of 8.5 with a spanning ratio of Zn to Al from 4:1, 3:1, and 2:1. The XRD patterns showed crystal nanostructure of Zn/Al LDHs was successfully formed. The lattice parameters (a and c) were slightly increased with the increasing of Zn/Al molar ratio. A larger hexagonal platelet is observed in the SEM image align with the high molar ratio of Zn/Al synthesized. The same trend has been observed in the FTIR spectra.
 
 Keywords: Zn/Al LDH, alkali-free route, different molar ratio, XRD, SEM, FTIR

Solution synthesis and dielectric properties of alumina thin films: understanding the role of the organic additive in film formation.

Alumina thin films are synthesized by combustion synthesis of mixtures of aluminium nitrate (ALN) and methylcarbazate (MCZ). The interdependence of the ratio of oxidizer and reducing agent on composition, microstructure and electronic properties of the resulting oxide layers is investigated. The dielectric and insulating behaviour is improved by addition of different amounts of MCZ (MCZ : ALN = 0.67 or 2.5). In this way films (thickness ∼140 nm) with a dielectric constant κ of 9.7 and a dielectric loss tan δ below 0.015 can be achieved. Medium concentrations of MCZ (MCZ : ALN = 1.0 or 1.5) lead to films with lower performance, though. Our studies indicate two opposing effects of the organic additive. Removal of organic residues during film formation as combustion gases is potentially detrimental. Larger amounts of MCZ, however, cause condensation reactions in the precusor mixture, which improve the microstructure. The porosity of the films can be sucessfully analyzed by positron annihilation liftetime studies. In this way the impact of the organic ligand sphere on the resulting microstructure can be quantified. Samples prepared from ALN alone exhibit mesopores and also larger micropores. In contrast, the formation of mesopores can be inhibited by addition of MCZ.

Application of Aluminium Nitrate for Extraction Reprocessing of Spent Nuclear Fuel

Application of Aluminium Nitrate for Extraction Reprocessing of Spent Nuclear Fuel

Application of Aluminium Nitrate for Extraction Reprocessing of Spent Nuclear Fuel

Application of Aluminium Nitrate for Extraction Reprocessing of Spent Nuclear Fuel