Proportions Of Metal Ions Research Articles

Designing Different Heterometallic Organic Frameworks by Heteroatom and Second Metal Doping Strategies for the Electrocatalytic Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) are considered one of the most significant electrocatalysts for the sluggish oxygen evolution reaction (OER). Hence, a series of novel N,S-codoped Ni-based heterometallic organic framework (HMOF) (NiM-bptz-HMOF, M = Co, Zn, and Mn; bptz = 2,5-bis((3-pyridyl)methylthio)thiadiazole) precatalysts are constructed by the heteroatom and second metal doping strategies. The effective combination of the two strategies promotes electronic conductivity and optimizes the electronic structure of the metal. By regulation of the type and proportion of metal ions, the electrochemical performance of the OER can be improved. Among them, the optimized Ni6Zn1-bptz-HMOF precatalyst exhibits the best performance with an overpotential of 268 mV at 10 mA cm-2 and a small Tafel slope of 72.5 mV dec-1. This work presents a novel strategy for the design of modest heteroatom-doped OER catalysts.

Molding law of traditional Chinese medicine gel plaster based on physicochemical properties of raw materials and intermediates

This paper aims to study the correlation between the physicochemical properties of raw materials and intermediates and the molding quality and law of traditional Chinese medicine(TCM) gel plaster by using TCM slices and powder as raw materials. 48 TCM compounds are selected as model prescriptions to prepare gel plasters. The rotational rheometer is used to determine the rheological parameters of the plaster, including storage modulus(G'), loss modulus(G″), yield stress(τ), and creep compliance [J(t)]. The molding quality of the prepared TCM gel plaster is evaluated by subjective and objective measures. Clustering and principal component analysis are conducted to evaluate the physical properties of the plaster. By measuring the rheological properties of the plaster, the molding quality of the TCM gel plaster can be predicted, with an accuracy of 83.72% after seven days of modeling and 88.37% after 30 days of modeling. When the parameters such as G' and G″ of the plaster are large, and the [J(t)] is small, the molding quality of the plaster is better. When the plaster coating point is no less than 3, it is difficult to be coated. In addition, when the proportion of metal ions in the prescription is higher, the 30-day forming quality of the plaster is mainly affected, and the viscosity of the plaster is poor. If the prescription contains many acidic chemical components, the 7-day forming quality of the plaster is mainly affected, with many residuals. The results suggest that the rheological properties of the plaster can be used to predict the molding quality of TCM slice and powder gel plaster. It can provide a reference for the development of TCM gel plaster prescriptions.

Получение TiN-покрытий реактивным анодным испарением титана в разряде с самонакаливаемым полым катодом

A method for TiN-coatings deposition by anodic evaporation of titanium in a high-current gas discharge (30 A) with a self–heated hollow cathode in an Ar+N2 medium is proposed. Optical spectral analysis shows that a large amount of activated titanium is present in the gas-discharge plasma, and the proportion of metal ions coming from the plasma to the substrate, taking into account the single-charge ions, reaches 70%. At a nitrogen flow of 5 sccm, TiN-coatings with a thickness of 2 µm and a hardness of up to 24 GPa were obtained. The deposition rate at a distance of 7 cm from the vapor source was ~4 µm/h.

Conversion of plastic waste into CNTs using Ni/Mo/MgO catalyst—An optimization approach by mixture experiment

ABSTRACTA combustion technique is used to study the synthesis of carbon nano tubes from waste plastic as a precursor and Ni/Mo/MgO as a catalyst. The catalytic activity of three components Ni, Mo, MgO is measured in terms of amount of carbon product obtained. Different proportions of metal ions are optimized using mixture experiment in Design expert software. D-optimal design technique is adopted due to nonsimplex region and presence of constraints in the mixture experiment. The activity of the components is observed to be interdependent and the component Ni is found to be more effective. The catalyst containing Ni0.8Mo0.1MgO0.1 yields more carbon product. The structure of catalyst and CNTs are studied by using SEM, XRD, and Raman spectroscopy. SEM analysis shows the formation of longer CNTs with average diameter of 40–50 nm.

THE AGGREGATION EFFECT OF METAL IONS ON SILVER SOL AND THE FRACTAL STRUCTURE FORMED

We have studied the aggregation of silver sol by mixing silver sol with several kinds of ions. We found that it is very difficult for the monovalent metal ions to make silver sol aggregate. The metal ions of the second main group can make silver sol aggregate and form fractal state. With the radii of metal ions increase, their ability of aggregation increases accordingly. The metal ion of the third main group A13+ can also make silver sol aggregate and form fractal state. As for acid radical ions, they can not make silver sol aggregate directly, but they can influence the speed of the aggregation and final state of silver sol. The simple explanations of these phenomena were given. We also found that the speed of aggregation and final state of silver sol were determinded by the state of silver sol and the proportion of metal ions in silver sol.