Utilization of Environmentally Benign Hydrogels and Their Networks as Reactor Media in the Catalytic Reduction of Nitrophenols

Catalytic innovations: Improving wastewater treatment and hydrogen generation technologies

The effective reduction of hazardous organic pollutants in wastewater is a pressing global concern, necessitating the development of advanced treatment technologies. Pollutants such as nitrophenols and dyes, which pose significant risks to both human and aquatic health, making their reduction particularly crucial. Despite the existence of various methods to eliminate these pollutants, they are not without limitations. The utilization of nanomaterials as catalysts for chemical reduction exhibits a promising alternative owing to their distinguished catalytic activity and substantial surface area. For catalytically reducing the pollutants NaBH4 has been utilized as a useful source for it because it reduces the pollutants quiet efficiently and it also releases hydrogen gas as well which can be used as a source of energy. This paper provides a comprehensive review of recent research on different types of nanomaterials that function as catalysts to reduce organic pollutants and also generating hydrogen from NaBH4 methanolysis while also evaluating the positive and negative aspects of nanocatalyst. Additionally, this paper examines the features effecting the process and the mechanism of catalysis. The comparison of different catalysts is based on size of catalyst, reaction time, rate of reaction, hydrogen generation rate, activation energy, and durability. The information obtained from this paper can be used to steer the development of new catalysts for reducing organic pollutants and generation hydrogen by NaBH4 methanolysis.

Reduction of 4-nitrophenol and 2-nitroaniline using immobilized CoMn2O4 NPs on lignin supported on FPS

In the present work, fibrous phosphosilicate (FPS) is functionalized by using octakis[3(3-aminopropyltriethoxysilane)propyl]octasilsesquioxane (APTPOSS) groups.

Kinetic research on dechlorinating dichlorobenzene in aqueous system by nano-scale nickel/iron loaded with CMC/NFC hydrogel

In this study, we reported on the nano-scale nickel/iron particles loaded in carboxymethyl/nanofibrillated cellulose (CMC/NFC) hydrogel for the dechlorination of o-dichlorobenzene (DCB) in aqueous solution. The biodegradable hydrogel may provide an ideal supporting material for fastening the bimetallic nano-scale particles, which was examined and characterized by TEM, SEM-EDX, FT-IR and BET. The performance of the selected bimetallic particles was evaluated by conducting the dechlorination of DCB in the solution under different reaction conditions (e.g., pH, dosage of nickel/iron nanoparticles and temperature). The results showed that about 70% of DCB could be dechlorinated at 20 °C in 8 h, which indicated that the immobilized reactive material had a high reduction activity when Ni/Fe loading dosage in the hydrogel (18 wt%) was considered. Moreover, the reduction behavior agreed to the pseudo-first order reaction, in which the dechlorination rate was irrelative to the pH aqueous solution. A kinetic model for predicting the concentration of DCB during the reduction reaction was established based on the experimental data.

The reduction of 4-nitrophenol and 2-nitroaniline by the incorporation of Ni@Pd MNPs into modified UiO-66-NH2 metal–organic frameworks (MOFs) with tetrathia-azacyclopentadecane

UiO-66-NH₂/TTACP/Ni@Pd MNPs exhibited excellent catalytic activity for the reduction of 2-nitroaniline and 4-nitrophenol.

An enzyme-like imprinted-polymer reactor with segregated quantum confinements for a tandem catalyst

This study was aimed at addressing the present challenge in tandem catalysts, as to how to furnish catalysts with tandem catalytic-ability without involving the precise control and man-made isolation of different types of catalytic sites. This objective was realized by constructing an enzyme-like imprinted-polymer reactor made of a unique polymer composite inspired from the compartmentalization of cells, a composite of a reactive imprinted polymer (containing acidic catalytic sites), and encapsulated metal nanoparticles (acting as catalytic reduction sites). The compilation of two types of catalytic sites with admissible access allowed this reactor to behave like compartments of cells for enzymatic reactions and hence catalytically constituted two quantum interaction-segregated domains, which led to the occurrence of catalytic tandem processes. Unlike the reported functional reactors that run tandem catalysis by largely depending on the precise control and man-made isolation of different types of catalytic sites, tandem catalysis in this reactor run naturally with segregated quantum confinements, which does not involve the precise control and isolation of different types of catalytic sites. This protocol presents new opportunities for the development of functional catalysts for complicated chemical processes.

This study was aimed at addressing the present challenge in tandem catalysts: how to furnish catalysts with tandem catalytic-ability without involving the precise control and man-made isolation of different types of catalytic sites.

Size dependence of silver nanoparticles in carboxylic acid functionalized mesoporous silica SBA-15 for catalytic reduction of 4-nitrophenol

Silver nanoparticles with a size around 3 nm are formed within the mesopores of –COOH functionalized mesoporous silica SBA-15, and they are highly active in the catalytic reduction of 4-nitrophenol.

Preparation of a novel high-strength polyzwitterionic liquid hydrogel and application in catalysis

A new polymeric hydrogel P(PVIS–AA) based on zwitterionic liquids (1-propyl-3-vinyl imidazole sulfonate) (PVIS) and acrylic acid (AA) was prepared by free-radical polymerization.