Hydrothermal Synthesis and Phase‐, Morphology‐Evolution Mechanism of Lead Titanate Nanostructures Assisted with Tetramethylammonium Hydroxide

Abstract

Lead titanate nanostructures with different phases and morphologies, layered hexagonal PbTiO 2 (CO 3 ) 0.3 -(NO 3 ) 0.35 (OH) nanosheets, pyrochlore Pb 2 Ti 2 O 6 nanodendites, pre-perovskite PbTiO 3 nanofibres and perovskite PbTiO 3 nanoplates, have been synthesized via a conventional hydrothermal route assisted with different concentrations of tetramethylammonium hydroxide (TMAH). X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM) were employed to characterize the phase, morphology and growth behavior of the synthesized samples. The results reveal that at low TMAH concentration the obtained samples are mainly of PbTiO 2 (CO 3 ) 0.3 (NO 3 ) 0.35 (OH) nanosheets. With the TMAH concentration increasing, the obtained samples change to pyrochlore Pb 2 Ti 2 O 6 nanodendites, pre-perovskite PbTiO 3 nanofibres and perovskite PbTiO 3 nanoplates in turn. With the basis of the experimental results, the phase-and morphology-evolution mechanism of the lead titanate nanostructures is discussed by combining the analysis of the lattice structure feature and the properties of TMAH.

Na3K6(CO3)3(NO3)2X·6H2O (X = NO3, Cl, Br): Exploring High-Performance UV Birefringent Crystals Induced by Coplanar π-Conjugated CO3 and NO3 Groups

“…Meanwhile, the anisotropic polarization of CO 3 and NO 3 is superior to that of BO 3 , and they can be also able to penetrate the UV or even deep-UV region; so CO 3 and NO 3 are more suitable for the construction of birefringent materials. − This motivates our interest in finding new UV birefringent crystals in the carbonate nitrate family. Based on a survey of the Inorganic Crystal Structure Database (ICSD with the version of 5.1.0., the last release of ICSD-2023–02) and recent publications, there are 12 synthetic members reported in the carbonate nitrate family, including (Tl 0.85 Cr 0.15 )­Sr 4 Cu 2 (CO 3 ) 0.5 (NO 3 ) 0.5 O 7 , [Co­(CO 3 )­(NH 3 ) 4 (NO 3 )] 2 ·H 2 O, [Pt­(NH 3 ) 2 ] 4 (CO 3 ) 2 (NO 3 ) 4 ·3H 2 O, Co­(CO 3 )­(NH 3 ) 4 NO 3 , Co­(NH 3 ) 5 (CO 3 )­NO 3 ·H 2 O, Ca 5 (UO 2 (CO 3 ) 3 ) 2 (NO 3 ) 2 ·10H 2 O, Na 3 Rb 6 (CO 3 ) 3 (NO 3 ) 2 Cl·6H 2 O, Na 3 Rb 6 (CO 3 ) 3 (NO 3 ) 2 Br·6H 2 O, Pb 6 O 4 (OH)­(NO 3 )­(CO 3 ), PbTiO 2 (CO 3 ) 0.3 (NO 3 ) 0.35 (OH), (NH 3 ) 6 Rh 2 (OH) 2 (CO 3 )­(NO 3 ) 2 ·H 2 O, and (NH 3 ) 6 Co 2 (OH) 2 (CO 3 )­(NO 3 ) 2 ·H 2 O . A few of them have systematically reported their optical and physicochemical properties.…”

“…This motivates our interest in finding new UV birefringent crystals in the carbonate nitrate family. Based on a survey of the Inorganic Crystal Structure Database (ICSD with the version of 5.1.0., the last release of ICSD-2023−02) and recent publications, there are 12 synthetic members reported in the carbonate nitrate family, including (Tl 0.85 Cr 0.15 )Sr 4 Cu 2 (CO 3 ) 0.5 (NO 3 ) 0.5 O 7 ,29 [Co(CO 3 )-(NH 3 ) 4 (NO 3 )] 2 •H 2 O, 30 [Pt(NH 3 ) 2 ] 4 (CO 3 ) 2 (NO 3 ) 4 •3H 2 O, 31 Co(CO 3 )(NH 3 ) 4 NO 3 , 32 Co(NH 3 ) 5 (CO 3 )NO 3 •H 2 O, 33 C a 5 ( U O 2 ( C O 3 ) 3 ) 2 ( N O 3 ) 2 • 1 0 H 2 O ,3 4 Na 3 Rb 6 (CO 3 ) 3 (NO 3 ) 2 Cl•6H 2 O,35 Na 3 Rb 6 (CO 3 ) 3 (NO 3 ) 2 Br• 6 H 2 O ,3 6 P b 6 O 4 ( O H ) ( N O 3 ) ( C O 3 ) ,3 7 PbTiO 2 (CO 3 ) 0.3 (NO 3 ) 0.35 (OH),38 (NH 3 ) 6 Rh 2 (OH) 2 (CO 3 )-(NO 3 ) 2 •H 2 O, 39 and (NH 3 ) 6 Co 2 (OH) 2 (CO 3 )(NO 3 ) 2 •H 2 O.…”

“…3 4 Na 3 Rb 6 (CO 3 ) 3 (NO 3 ) 2 Cl•6H 2 O,35 Na 3 Rb 6 (CO 3 ) 3 (NO 3 ) 2 Br• 6 H 2 O ,3 6 P b 6 O 4 ( O H ) ( N O 3 ) ( C O 3 ) ,3 7 PbTiO 2 (CO 3 ) 0.3 (NO 3 ) 0.35 (OH),38 (NH 3 ) 6 Rh 2 (OH) 2 (CO 3 )-(NO 3 ) 2 •H 2 O, 39 and (NH 3 ) 6 Co 2 (OH) 2 (CO 3 )(NO 3 ) 2 •H 2 O.…”

Hydrothermal synthesis and photocatalytic activity of butterfly-like CaTiO3 dendrites with dominant {101} facets

“…( ) ions, flower-like ZnO nanospheres self-assembled by nanosheets [26] and pyrochlore Pb 2 Ti 2 O 6 nanodendrites [27] were indeed hydrothermally synthesized. Herein, we propose a novel hydrothermal route for morphology-controlled synthesis of butterfly-like CaTiO 3 dendrites dominantly bounded with {101} facets, in which TMAH was used as a mineralizer instead of a strong alkali of NaOH and without any organic solvent added to the hydrothermal system.…”