scholarly journals Synthesis of Hierarchically Porous Metal Oxide Monoliths via Sol–Gel Process Accompanied by Phase Separation From Divalent Metal Salts: A Short Review

2021 ◽  
Vol 3 ◽  
Author(s):  
Xuanming Lu ◽  
Kazuki Nakanishi
Keyword(s):  
Phase Separation ◽  
Metal Oxide ◽  
Sol Gel ◽  
Porous Metal ◽  
Short Review ◽  
Divalent Metal ◽  
Metal Salts ◽  
Hierarchically Porous ◽  
Metal Phosphates ◽  
Sol Gel Process

The sol–gel process accompanied by phase separation is one of the methods to prepare hierarchically porous monoliths, hierarchically porous monolith, which is applicable not only to oxides but also to various materials compositions such as metal phosphates, organic-polymers/carbons, metal-organic frameworks. It is not until recently, however, that progress has been made in the preparation of low-valence metal oxide HPMs, such as those of magnesium, manganese, cobalt, nickel, etc. Due to the difficulty of divalent metal precursors to form homogeneous gels, different approaches from those established for trivalent and tetravalent counterparts have been attempted. This short review introduces the methods and trials in the preparation of metal oxide HPMs from divalent metal salts.

Synthesis of hierarchically porous MnO/C composites via a sol–gel process followed by two-step combustion for lithium-ion batteries

2020 ◽  
Vol 44 (28) ◽  
pp. 12307-12316
Author(s):  
Wei Liu ◽  
Daoyan Feng ◽  
Hui Yang ◽  
Xingzhong Guo
Keyword(s):  
Phase Separation ◽  
Lithium Ion Batteries ◽  
Sol Gel ◽  
Lithium Ion ◽  
Hierarchically Porous ◽  
Sol Gel Process

Hierarchically porous MnO/C composites with interconnected macropores and co-continuous skeletons were fabricated via a sol–gel process combined with phase separation, followed by a two-step combustion.

scholarly journals Preparation of a hierarchically porous AlPO4monolith via an epoxide-mediated sol–gel process accompanied by phase separation

2013 ◽  
Vol 14 (4) ◽  
pp. 045007 ◽  
Author(s):  
Wenyan Li ◽  
Yang Zhu ◽  
Xingzhong Guo ◽  
Kazuki Nakanishi ◽  
Kazuyoshi Kanamori ◽  
...  
Keyword(s):  
Phase Separation ◽  
Sol Gel ◽  
Hierarchically Porous ◽  
Sol Gel Process

scholarly journals Hierarchically porous monoliths based on low-valence transition metal (Cu, Co, Mn) oxides: gelation and phase separation

2020 ◽  
Vol 7 (11) ◽  
pp. 1656-1666 ◽  
Author(s):  
Xuanming Lu ◽  
Kazuyoshi Kanamori ◽  
Kazuki Nakanishi
Keyword(s):  
Phase Separation ◽  
Sol Gel ◽  
Average Molecular Weight ◽  
Reaction Parameters ◽  
Valence Transition ◽  
Hierarchically Porous ◽  
Sol Gel Process ◽  
Crystalline Metal ◽  
Hydrolysis And Polycondensation ◽  
Mn Oxides

Abstract Hierarchically porous monoliths based on copper (Cu), cobalt (Co) and manganese (Mn) oxides with three-dimensionally (3D) interconnected macropores and open nanopores were prepared using metal bromides as precursors via a sol–gel process accompanied by phase separation. The difficulty of gelation for low-valence metal cation was overcome by introducing a highly electronegative Br atom near to the metal atom to control the rates of hydrolysis and polycondensation. The 3D interconnected macropores were obtained using appropriate polymers to induce phase separation. The domain sizes of macropores and skeletons can be controlled by reaction parameters such as concentration and/or average molecular weight of polymers, and the amount of hydrochloric acid. The crystalline metal oxide monoliths with their 3D interconnected macroporous structure preserved were obtained after heat treatment in air.

scholarly journals CYCLOTRIPHOSPHAZENE-METAL OXIDE HYBRIDS BY A NONHYDROLYTIC SOL-GEL PROCESS.

1999 ◽  
Vol 10 (0) ◽  
pp. 714-719
Author(s):  
LAURENCE CROUZET ◽  
DOMINIQUE LECLERCQ
Keyword(s):  
Metal Oxide ◽  
Sol Gel ◽  
Sol Gel Process

Preparation of Macroprous C12A7 Mayenite Monoliths via a Sol-Gel Process with Nitrates as Precursors

2018 ◽  
Vol 768 ◽  
pp. 211-217 ◽  
Author(s):  
Rui Wang ◽  
Yu Kun Sun ◽  
Bao Jia Qi Jiang ◽  
Hui Yang ◽  
Xing Zhong Guo
Keyword(s):  
Heat Treatment ◽  
Phase Separation ◽  
Binary System ◽  
Propylene Oxide ◽  
Crystalline Phase ◽  
Sol Gel ◽  
Single Crystalline ◽  
Sol Gel Process

Macroporous Ca12Al14O33(C12A7) mayenite monoliths have been successfully prepared via a sol-gel process in the presence of propylene oxide (PO) and poly (ethyleneoxide) (PEO). Gelation of CaO-Al2O3binary system with nitrates salts as additional precursors is accelerated by PO as an acid scavenger, while PEO works as a phase separation inducer to mediate the phase separation of the system. Appropriate PO and PEO amounts allow the formation of monolithic xerogel with interconnected macropores and co-continuous skeletons. The resultant dried gels are amorphous and the single crystalline phase Ca12Al14O33mayenite forms after heat-treatment at 1100 °C in air, while the macrostructure is preserved with a porosity as high as 78% and smoother and denser skeletons.

Introduction of Organic Moieties into Transition-Metal Oxide Matrices via Phosphonate Groups

1998 ◽  
Vol 519 ◽  
Author(s):  
P.H. Mutin ◽  
C. Delenne ◽  
D. Medoukali ◽  
R. Corriu ◽  
A. Vioux
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Phosphonic Acid ◽  
Sol Gel ◽  
Transition Metal Oxide ◽  
Metal Alkoxide ◽  
Hydrolytic Condensation ◽  
Metal Phosphonates ◽  
Or Groups ◽  
Sol Gel Process

AbstractTransition metal oxide / phenylphosphonate hybrids with M/P ratios ranging from 1 to 5, (M= Ti, Zr) and metal phosphonates (M/P = 0.5) have been prepared by a sol-gel process involving in a first step the non-hydrolytic condensation between metal alkoxide and phosphonic acid leading to M-O-P bonds, followed by the hydrolysis-condensation of the remaining M-OR groups. The composition, texture and structure of the materials were investigated using EDX, TGA, XRD, IR and 31P NMR.

Sign in / Sign up

Export Citation Format

Share Document