Solvothermal synthesis of flower‐like lanthanum tartrate and lanthanum oxide microspheres in ethanol‐water mixed system

Abstract

Monodispersed lanthanum tartrate microspheres with flower-like shape were synthesized by a mild solvothermal method using ethanol-water mixed system as the solvent. Lanthanum oxide with reserved spherical shape was subsequently fabricated by a following calcination process. X-ray diffraction analyses (XRD), X-ray spectroscopy (EDS), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA) were employed to characterize the composition, structure, and morphology of the products. The lanthanum tartrate microspheres were aggregated by nanosheets as petals. Size of the aggregation and thickness of the petal vary with the vol.% of ethanol. As the vol.% of ethanol increases the degree of aggregation and the thickness of the petal decrease, and other properties such as the size distribution, dispersion are also modulated. These alterations can be interpreted by the changing dielectric constant of mixed solvent. Such lanthanum tartrate can be applied to fabricate micro-sphereshaped lanthanum oxide after calcination.

Ethanol-assisted hydrothermal synthesis of LiNi0.5Mn1.5O4 with excellent long-term cyclability at high rate for lithium-ion batteries

“…Fig. 28,29 The relationship between the particle radius (r) and the solvent dielectric constant (3) was described as 1/r ¼ A + B/3, where A and B are regarded as constants. Both patterns can be assigned to cubic spinel LiNi 0.5 Mn 1.5 O 4 (JCPDS Card no.…”

“…2 shows the XRD patterns of LiNi 0.5 Mn 1.5 O 4 synthesized by the ethanol-assisted hydrothermal method and precipitation method. 28,29 Thus, decreasing the dielectric constant leads to smaller particle sizes. : 80-2162).…”

Synthesis of porous peanut-like LiNi0.5Mn1.5O4 cathode materials through an ethylene glycol-assisted hydrothermal method using urea as a precipitant

“…However, as for the precursor synthesized in the presence of EG, the highly uniform Ni 0.25 Mn 0.75 CO 3 particles with much smaller particle size are obtained, as shown in Fig. 21,22 The relationship between the particle radius (r) and the solvent dielectric constant (ε) is described as 1/r = A + B/ε, where A and B can be regarded as constants. This indicates that the EG-assisted hydrothermal process can decrease the size and agglomeration degree of particles.…”

“…1(b). 21,22 Therefore, the decrease of the dielectric constant leads to smaller particle size. This phenomenon is in good agreement with the results of Ref.…”

Spherical Microstructures of Lu2O3:Ln3+ (Ln=Tm, Dy, Tb, Eu): Rapid Microwave‐Assisted Synthesis, Energy Transfer, and Multicolor Emission

“…Under different solvent, the dielectric constant of solution was different. Adding low dielectric medium (ethanol) to aqueous solution will alter the thermodynamics of reaction system and nucleation kinetics, which will result the supersaturating of solution . So, the nucleation rate will be increase and the primary particle size decreases.…”