Controlled Self-Assembly of Sm₂O₃ Nanoparticles into Nanorods: Simple and Large Scale Synthesis using Bulk Sm₂O₃ Powders

Abstract

Monodisperse samaria nanospheres and nanorods have been synthesized from commercial bulk Sm2O3 powders and various capping long-chain alkyl acids (e.g., oleic acid, myristic acid, decanoic acid). The synthesized materials were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform IR, thermogravimetric analysis, and N2 adsorption/desorption isotherms was employed to characterize these materials. The results revealed that the synthesis of nanorods consists of two steps of growth: (i) the nanoparticles were formed at relatively low temperature (120−140 °C) by Ostwald ripening and (ii) were followed by oriented attachment of these nanoparticles at higher temperature (160−200 °C) to produce the nanorods (average size of 7 nm × 160 nm). Furthermore, the width of nanorods can be controlled by the length of capping alkyl chain agents; on the basis of the experimental results, it seems that a longer alkyl chain agent leads to thinner nanorods; however, the length of nanorods remains unchanged. For the whole process, the possible Ostwald ripening and oriented attachment mechanisms were also discussed. The XPS results for the calcined nanorods sample shows the presence of two oxidation states, Sm3+/Sm2+ (it is found to be 40% Sm2+), and three components by deconvolution of O 1s peak indicating the defected structure. The surface chemical composition is found to be Sm2O3−x (x = 1.8). We believe that this synthetic method is simple, highly reproducible, inexpensive, and applicable for large-scale production.

Synthesis and characterization of Sm(OH)3 and Sm2O3 nanoroll sticks

“…For Sm 2 O 3 , a broad peak at 3400 cm -1 was due to H 2 O (or hydrated) adsorbed on the oxide surface. The peaks at 1412 and 1473 cm -1 were commonly observed and attributed to symmetric and asymmetric stretching of COO -, respectively [15]. Figure 5 displays the diffuse reflectance UV-Vis-NIR absorption spectra of Sm(OH) 3 Although the intensities were different before and after thermal annealing all the UV-Vis-NIR absorption peaks were in good match with the electronic transitions of Sm(III) [19,33].The absorption spectra between 900 and 2000 nm correspond to the f-f transitions from the ground state of 6 H 5/2 to 6 F 1/2,3/2,5/2,7/2,9/2,11/2 and 6 H 15/2 energy levels as assigned on the corresponding peaks [33].…”

“…Sm(OH) 3 has also been prepared since Sm 2 O 3 could be obtained by a post-thermal dehydration [11,12]. Facial solution-based synthetic methods include hydrothermal [13][14][15], precipitation [11,16], solgel [18], and template [19] methods. Many different morphologies have been synthesized and reported, including nanorods [11,[15][16][17]20], nanodisks [18], nanowires [21,22], submicrospindles [23], nanoparticles [24], and nanoplates [20,21].…”

Samarium Additive Effect onto the Nickel Electrodeposition Process

“…As shown in Fig. 14d, the O 1s core-level spectrum is characterized by the main peak at 531.18 eV, assigned to the oxygen of Sm(III)-O groups, 27 this indicates that the Sm(III) in the film could be in the form of oxides (Sm 2 O 3 ).…”

“…14c). The two prominent peaks at 1083.18 eV and 1110.38 eV correspond to Sm(III), 27,28 whereas the weak peak pair at about 1090 and 1119 eV is ascribed to Sm(II). 29 The presence of Sm(II) in the coating coincides with the formation mechanism of the samarium film previously proposed, in which includes the reduction of Sm(III) to Sm(II).…”

Room temperature synthesis of samarium oxide nanotubes using cost-effective electroless deposition method

“…Only a few studies have been reported on the synthesis of samarium oxide nanoparticles or nanorods using thermal composition [13] or hydrothermal synthesis [14]. Fabrication of metal nanostructures by the template deposition method, pioneered by Martin [15,16], is one of the important processes.…”