Bronze sodium tungsten precipitation synthesis and lithium intercalation

Author(s)

Martins, Tiago A. ; Goncalves, Roger ; Cabral, L. ; Machado, Thales Rafael ; Paiva, Robert da Silva ; Roca, Roman Alvarez ; Pereira, Ernesto Chaves ; San-Miguel, Miguel A. ; da Silva, E. Z. ; Longo, E.

• Document type: Journal article
• Source: Journal of Solid State Electrochemistry; v. N/A, p. 13-pg., 2024-10-19.

Abstract

Hexagonal sodium tungsten bronze (h-NaxWO3+x/2<middle dot>yH2O) nanorods were obtained by simple acid precipitation in 16 min at 97 degrees C, evidencing the saving of time and energy. The W-OH2 modes were observed in Raman and Fourier transform infrared (FTIR) spectra to confirm the presence of structural water. The h-NaxWO3+x/2<middle dot>yH2O was subjected to heat treatment at 300 degrees C to analyze the effects of heating on the material. X-ray photoelectron spectroscopy (XPS) and diffuse reflectance ultraviolet-visible absorption spectra (UV-vis) indicated the occurrence of diffusion on the surface-bulk of Na+ ions, and the band gap changed from 2.7 eV to 2.4 eV with heating. Electrochromic devices based on h-NaxWO3+x/2<middle dot>yH2O were constructed. The sample without heat treatment and with structural water loss presented the electrochromic efficiency of 127.5 cm2/C and 561.8 cm2/C, respectively, evidencing the creation of vacancies for the intercalation of lithium ions from heat treatment. Also, density functional theory calculations were performed to study the lithium diffusion process in the interstitial Na-WO6 channels of sodium tungsten bronze. (AU)

• FAPESP's process: 17/26105-4 - Multi-user equipment approved in grant 2016/23891-6 high performace computational cluster
• Grantee: Alex Antonelli
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 16/23891-6 - Computer modeling of condensed matter
• Grantee: Alex Antonelli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/20729-9 - Formation of Ag Nanoparticles by Laser Irradiation: An ab inicio Investigation
• Grantee: Luis Antônio Cabral
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 23/12673-1 - Calcium phosphate nanoparticles chemically modified with targeting components using click chemistry for the delivery of anticancer drugs
• Grantee: Thales Rafael Machado
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 20/14417-4 - Novel biomimetic nanosystems based on calcium orthophosphates covered by cellular membranes for bioimaging and controlled release of antineoplastics
• Grantee: Thales Rafael Machado
• Support Opportunities: Scholarships in Brazil - Post-Doctoral