Promoting the effect of cationic substitution on thermal stability and redox properties of new synthesized Keggin type lacunary polyoxometalates (L-POMs) Ni2.5PMo11 M(H2O)O39 (M = Co, Fe, Cu, Zn)

• Published in: International journal of materials research Vol. 113; no. 2; pp. 112 - 121
• Main Authors: El Arrouji, Imane, Oulmekki, Abdallah, Harrach, Ahmed, Taoufik, Mostafa, Lefebvre, Frédéric, Toyir, Jamil
• Format: Journal Article
• Language: English
• Published: Stuttgart De Gruyter 23-02-2022; Carl Hanser Verlag
• Subjects: Cobalt; Copper; Crystallography; Differential scanning calorimetry; Electrochemical analysis; Heat transfer; Iron; Keggin structure; Polyoxometalates; Polyoxometallates; Redox behavior; Stability analysis; Substitutes; Synthesis; Thermal resistance; Thermal stability; Thermogravimetric analysis; Transition metals; Zinc
• ISSN: 1862-5282; 2195-8556
• DOI: 10.1515/ijmr-2021-8294

New lacunary Keggin type polyoxometalate salts (Ni
PMo
(H
O)O
= Co, Fe, Cu, Zn), were synthesized using the inorganic condensation method. X-ray diffraction and infrared spectroscopy results showed that the Keggin structure of the salts was preserved. The thermal stability was checked by differential scanning calorimetry coupled with thermogravimetric analysis showing that the thermal resistance was significantly improved by the incorporation of the metals into polyoxometalates. Proton and molybdenum substitution respectively by nickel and cobalt, iron, copper and zinc metals induced a positive effect on the crystallographic configuration of the prepared salts allowing them a better thermal resistance (up to 580 °C). Cyclic voltammetry revealed an interesting electrochemical property of synthesized samples, especially for Ni
PMo
Zn(H
O)O
sample in which the presence of zinc greatly boosted the redox behavior.