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

Abstract

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.

Treatment of Wastewater Containing Pharmaceutical Micropollutants by Adsorption under Flow in Highly Porous Carbon Monoliths

“…In this context, we have developed carbon-based adsorbents for wastewater treatment, which are easy to handle and ideal for flow-through processes . Highly porous carbon monoliths (CM) with well-controlled hierarchical micro/meso/macropores were obtained by replicating silica monoliths by hydrothermal nanocasting. , CM proved to be very suitable for high flow, a low drop pressure, and a homogeneous contact time. ,, This family of monoliths, prepared by spinodal decomposition, can have different natures (silica, zeolites, titania, etc.) and has proven to be extremely efficient in flow chemistry in many applications such as high-performance liquid chromatography and electrochromatography, , heterogeneous catalysis, − photocatalysis, biocatalysis, ,, oil purification, decontamination of water containing radioactive elements, metal capture, , etc.…”

“…28,29 CM proved to be very suitable for high flow, a low drop pressure, and a homogeneous contact time. 28,30,31 This family of monoliths, prepared by spinodal decomposition, 32 can have different natures (silica, zeolites, titania, etc.) and has proven to be extremely efficient in flow chemistry in many applications such as high-performance liquid chromatography and electrochromatography, 33,34 heterogeneous catalysis, 35−40 photocatalysis, 30 biocatalysis, 28,41,42 oil purification, 43 decontamination of water containing radioactive elements, metal capture, 44,45 etc.…”