Single-crystal Na2Ti6O13 nanorings formed by self-coiling of a nanobelt

A single-source molten salt synthesis of rod-shaped Na2Ti6O13 crystals

“…The rod-like Na 2 Ti 6 O 13 crystals with 200-500 nm diameter and 1-5 μm length (Fig. 7b) are similar to products from traditional molten salt methods [1,5,10,11]. When sintering temperature below 500 1C, the peaks of Na 2 Ti 6 O 13 do not appear, and the crystalline products just contain anatase ( Fig.…”

“…6d). Although the sintering temperature in this method is close to normal molten salt systems (825-1100 1C) [10,11], the sintering time (only need to sinter PX crystals at 900 1C for 30 min) is much shorter than conventional molten salt methods ( 42 h) [1,5,10,11]. In addition, the crystallinity of Na 2 Ti 6 O 13 is 96.3% (calculated from XRD pattern), which is higher than the Na 2 Ti 6 O 13 from the hydrothermal method [6][7][8].…”

“…However, up to now, a few methods have been reported for synthesis of Na 2 Ti 6 O 13 crystals, such as hydrothermal reaction of NaOH-TiO 2 [6][7][8], sol -gel reaction of Ti-butoxide and Na-tertbutoxide [9], solidstate molten salt reaction of Na 2 C 2 O 4 -NaCl-TiO 2 [5,10], NaCl-Na 2 CO 3 -TiO 2 [1,11] or Na 2 O-TiO 2 [12]. However, these conventional methods reported are not cost-effective.…”

Fluorescent bracelet-like Cu@cross-linked poly(vinyl alcohol) (PVA) microrings by a hydrothermal process

“…Several crystalline plane polarized semiconductor nanorings, such as SnO 2 28 and ZnO nanorings, 10 have been prepared through the solid-vapor process, the formation mechanism of which was attributed to the minimization of electrostatic energy between polarized crystal planes. In the hydrothermal process, Ag 2 VO 4 , 11 CuO, 12 VO 2 13 and Na 2 Ti 6 O 13 14 nanorings can also be obtained with the help of electrostatic interaction of polarized crystal planes. Apparently, the polarized surface induced bending mechanism can not be applied to interpret the self-coiling process of Cu nanowires, because there is no polarized crystal plane in Cu.…”

Chiral Nanoceramics

“…It was proposed that the formation of helices was thermodynamically and kinetically favored because the neighboring faces can achieve charge‐neutrality and the neighboring loop can assist the growth of the crystal at its termini in a helix. Based on the solid–vapor growth method, such an electrostatic mechanism in the solid–vapor growth process, various helical and spring structured SiO 2 , [ 61 ] SnO 2 , [ 62 ] CuO, [ 63 ] Ag 2 V 4 O 11 , [ 64 ] Ag 1.2 V 3 O 8 , [ 65 ] Na 2 TiO 6 O 13 , [ 66 ] K 2 Ti 6 O 13 , [ 67 ] etc., micro or nanoceramic materials were prepared. Note however, that in these studies and many other studies in this section, the structures are obviously chiral, but the product is racemic.…”