Alpha metallic hydroxides vs. metallic glycerolates: synthesis, properties and applications

• Grant number: 22/04127-4
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: December 01, 2022
• End date: March 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Lucio Angnes
• Grantee: Irlan dos Santos Lima
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The well-known Tower's method was created in 1924 and has been widely used for almost a century. At IQUSP, its use has been quite broad, mainly for the synthesis of nanomaterials, with emphasis on transition metal hydroxides, being Ni one of the metals most used. Over the years, the Tower method was used following what the literature described, using X-ray diffraction to monitor the quality of the material formed. In 2020, after the synthesis of such material, a student from our group also chose to perform the elemental analysis of the material obtained, detecting a carbon content unusually above of what was expected. At the time, there was no definitive explanation for this fact, and the C content was attributed to glycerin not eliminated in the washing process. Recently, we started to suspect about the formation of glycerolates of metals, since there may occur the formation of metallic glycerolates, metallic hydroxides and possibly mixed species (glycerolates + metallic hydroxides), considering that it was verified that both metallic glycerolates as metal hydroxides present very similar X-ray diffraction patterns, especially in relation to the low-angle peak attributed to the formation of lamellar structures. In this way, the the understanding of such processes is of fundamental importance and the evaluation of the potential of glycerolates of different metals may provide relevant results for the area of supercapacitors, batteries, electrocatalysis and electrochemical sensors. During this PhD project, we intend to develop nanomaterials based on alpha-NiCo(OH)2 (or NiCo-Gly, NiCo-G) in different proportions of nickel and cobalt, applying the modified Tower method (sol- gel) in the presence and absence of KOH base. The structural similarity observed in both materials will be investigated through the X-ray diffraction patterns (XRD) reported in the literature. This research will seek to answer whether the formation of alpha-NiCo(OH)2 occurs when the modified Tower method is applied or whether the formation of metallic glycerolates take place. In addition to comparing the results by XRD, the different materials will be compared by different spectroscopic and electrochemical techniques. Glycerolates and/or electroactive metal hydroxides should be used to prepare thin films, aiming at application in energetic technologies, such as electrocatalysts and electrode materials (positive) in hybrid supercapacitors. In addition, we should apply these materials for the development of sensors, aiming at the determination and quantification of different species with the use of electroanalytical techniques associated to flow techniques, such as Flow Injection Analysis (FIA) and Batch Injection Analysis (BIA), for what electrochemical cells will be built and optimized. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GONCALVES, JOSUE M.; GHORBANI, ALIREZA; RITTER, TIMOTHY G.; LIMA, IRLAN S.; SARAY, MAHMOUD TAMADONI; PHAKATKAR, ABHIJIT H.; SILVA, VINICIUS D.; PEREIRA, RAFAEL S.; YARIN, ALEXANDER L.; ANGNES, LUCIO; et al. Multimetallic glycerolate as a precursor template of spherical porous high-entropy oxide microparticles. Journal of Colloid and Interface Science, v. 641, p. 10-pg., 2023-03-22. (18/16896-7, 20/06176-7, 17/13137-5, 22/04127-4)

LIMA, IRLAN S.; GONCALVES, JOSUE M.; ANGNES, LUCIO. Ternary NiFeCo-glycerolate catalysts: rational design for improved oxygen evolution reaction efficiency. JOURNAL OF MATERIALS CHEMISTRY A, v. N/A, p. 10-pg., 2024-11-13. (22/04127-4)

LIMA, IRLAN S.; PEREIRA, RAFAEL S.; RITTER, TIMOTHY G.; SHAHBAZIAN-YASSAR, REZA; GONCALVES, JOSUE M.; ANGNES, LUCIO. Nickel Glycerolate Overcoming a High-Entropy Configuration for High-Performance Oxygen Evolution Reaction. CATALYSTS, v. 13, n. 10, p. 14-pg., 2023-10-01. (20/06176-7, 18/16896-7, 22/04127-4, 17/13137-5)