Tuning morphology, surface, and nanocrystallinity of rare earth vanadates by one-pot colloidal conversion of hydroxycarbonates

Autor(es)

Guida, Gabriela ^[1] ; Huband, Steven ^[2] ; Walker, Marc ^[2] ; Walton, Richard I. ^[3] ; de Sousa Filho, Paulo C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Campinas UNICAMP, Inst Chem, Dept Inorgan Chem, POB 6154, BR-13083970 Campinas, SP - Brazil

^[2] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands - England

^[3] Univ Warwick, Dept Chem, Coventry CV4 7AL, W Midlands - England

• Tipo de documento: Artigo Científico
• Fonte: NANOSCALE; v. 13, n. 9, p. 4931-4945, MAR 7 2021.
• Citações Web of Science: 0

Resumo

We show that particle size, morphology, nanocrystallinity, surface area, and defect density of (Y,Eu)VO4 structures can be tuned by one-pot colloidal conversion of rare earth hydroxycarbonates in water/ethylene glycol (EG) suspensions. Using small angle X-ray scattering, transmission electron microscopy and dynamic light scattering, we show how volume fractions of EG direct the amorphous to crystalline conversion at 1 atm/95 degrees C by controlling size and aggregation of hydroxycarbonate precursors. A template effect due to a Kirkendall-type conversion occurs for low EG contents, yielding solids with high densities of oxygen defects, as demonstrated by O-2 uptakes in thermogravimetry and X-ray photoelectron spectroscopy profiles. Starting from small and aggregated hydroxycarbonates high-porosity (Y,Eu)VO4 nanoparticles were produced with expanded unit cells and short-range (<100 angstrom) crystalline ordering. We explored the effects of synthesis on the textural, microstructure, and defects of (Y,Eu)VO4 solids, which were further correlated to the spectroscopic profiles of Eu3+-activated samples. We show that the ratios between Eu3+ 5D0 internal quantum yields and particle diameters can be directly correlated to the particle surface areas, opening new perspectives for theoretical detailing of f-f luminescence in YVO4 solids, and enabling accurate tuning of structure and applicability of colloidal vanadate nanoparticles for sensing and catalysis applications. (AU)

• Processo FAPESP: 18/08334-9 - Novos materiais avançados para aplicações em sensoriamento: um projeto colaborativo sobre a caracterização estrutural e espectroscópica de novos sólidos à base de terras raras
• Beneficiário: Paulo Cesar de Sousa Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/11764-2 - Estratégias na síntese de nanomateriais luminescentes para o desenvolvimento de novos sensores ópticos multimodais
• Beneficiário: Paulo Cesar de Sousa Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular