Current efficiency of synthesis magnesium hydroxide nanoparticles via electrodeposition

Abstract

Abstract:The nanograde particles of magnesium hydroxide [Mg(OH) 2 ] with lamella morphology were synthesized by the method of electrodeposition. The effects of operation parameters, such as Mg 2+ concentration and electric current density, interpolar distance and Na + concentration on current efficiency of synthesis magnesium hydroxide nanoparticles were investigated. The results show that the current efficiency can be reach to 76.53% under the conditions of Mg 2+ concentration 0.5mol/L, Na + concentration 1%, electric current density 40mA/cm 2 and electrode interpolar distance 4cm. The samples were characterized by X-ray diffractions (XRD) and field emission scanning electron microscopy (FESEM). IntroductionIn recent years, the synthesis of nanoscale Mg(OH) 2 has been the focus of considerable interest because of its potential properties in electronic, mechanical, electrochemistry, optical and topological [1][2][3][4][5] . Several methods have been used to prepare Mg(OH) 2 with controlled shape and size, such as ultrasonic-assisted [6] , precipitation [7] , sol-gel technique [8] , using bubbling setup [9] , hydrothermal route [10] and electrolysis of an aqueous magnesium salt solution [11] ,etc. Ranjit and Klabunde [12] have synthesized mesostructured Mg(OH) 2 using different anionic surfactants as template, but their process limited due to low current efficiency and economically unacceptable. In present study, the Mg(OH) 2 deposition processes from magnesium chloride hexahydrate was researched, and the effects of the variation of Mg 2+ concentration, electric current density, interpolar distance and Na + concentration on current efficiency were studied. Experimental MaterialsMagnesium chloride hexahydrate (MgCl 2 ·6H 2 O), sodium chloride(NaCl), potassium chloride(KCl) were supplied from Shenyang Chemical Reagent Co. Ltd, China, all of these chemicals are analytical pure grade and without further purification. Deionized water was employed for all experiments. Procedures of synthesis of Mg(OH) 2 nanoparticlesThe electrolysis procedure were performed in a single conventional compartment cell(capacity is 2.5L). The anode is graphite plate and the cathode is stainless steel plates with smooth surface. The electrolysis experiments were took out at room temperature. In a typical run, 100g of MgCl 2 ·6H 2 O is dissolve in 2L of deionized water to make a mother solution, the electrodes surface is both 100 cm 2 and the electrode interpolar distance is 4cm, the electric current density is 40 where η is current efficiency, m is the actual mass of metal hydroxide deposited, m*is theoretical mass of metal hydroxide deposited. The actual mass of metal hydroxide deposited(m) is determined by the mass after dry. The theoretical mass of metal hydroxide(m*) is calculated by the Faraday's law: m*=ItM/(nF) (2) where I is the applied current, t is the time, n is the number of electrons transferred in the elementary act of the electrode reaction, M is the mole mass of the metal hydroxide and F is the faraday constant. Physical char...