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Nanomaterials are emerging as important contributors in various applications and can be used especially in environmental catalysis. Herein, a brief summary on the basic knowledge of supercritical hydrothermal synthesis (SCWHS) is presented, including the synthesized functional nanomaterials, the effects of different experimental conditions on the properties of nanoparticles, and examples of their applications in environmental catalysis, highlighting the environmental and economic advantages of SCWHS. This review focuses on supercritical water as an environmentally friendly particle engineering tool for the production of high-quality, high-yield nanoparticles and the possibility of achieving their continuous production in industry. Nanoparticles are nucleated within a short time and their particle size can be controlled by SCWHS. Therefore, attention is given to the relationship between the formation and experimental conditions, as well as the properties of the obtained material in terms of particle size, surface area, crystallinity, morphology and surface properties. In addition, SCWHS can combine organic wastewater treatment, waste resource utilization and nanoparticle synthesis, and the in situ-generated nanoparticles can promote the oxidation of organic wastewater and the resourceful conversion of solid wastes as well as have production value as a by-product. The work may provide guidance for the further development of SCWHS, preparation of functional nanomaterials, and exploration of multiple applications. [ABSTRACT FROM AUTHOR]

Developing efficient and stable catalysts for synergistic removal of NOx and dioxin has always been key for controlling air pollution. For this, the hydrotalcite-like structured Cr(x)/LDO catalysts were successfully synthesized for synergistic removal of NOx and o-DCB using a co-precipitation method. The performance test results show that the Cr(0.25)/LDO catalyst has the best catalytic performance, and the NOx and o-DCB conversions are 89% and 82% at 250 °C, respectively. In addition, the reaction mechanism of NH3-SCR and o-DCB catalytic oxidation on the surface of the Cr(0.25)/LDO catalyst, and the interaction between the two reactions were investigated by designing in- situ DRIFTS experiments. The results indicate that the NH3-SCR reaction follows both E–R and L–H reaction mechanisms. The reaction pathway for the o-DCB oxidation process is proposed: o-DCB → chlorinated phenolate → benzoquinone → maleic acid, formic acid, acetic acid, etc. → H2O, CO2, HCl. Moreover, there are interactions between NH3-SCR and catalytic oxidation of o-DCB. At low temperature, there is obvious competitive adsorption between NH3/NO and o-DCB. The competitive adsorption between NH3/NO and o-DCB leads to the decrease of the o-DCB conversion. At high temperature, NH3-SCR and o-DCB oxidation exhibit a synergistic effect, NO2in situ-generated from the oxidation of NO can further participate in the o-DCB oxidation and reduce the accumulation of o-DCB oxidation intermediates on the catalyst surface. The research results contribute to understanding the reaction processes of Cr(x)/LDO catalysts and provide support for practical applications. [ABSTRACT FROM AUTHOR]

With the development of nanotechnology, nanocomposites have been used as bimodal contrast agents for magnetic resonance (MR) and computed tomography (CT) imaging. We have developed a facile method for the synthesis of iron oxide@bismuth sulfide magnetic core–shell nanocomposites. These bifunctional nanocomposites can be made water-soluble via PEG coating and present strong MRI/CT contrast enhancement. Evaluation of cytotoxicity by MTT assay shows that the nanocomposites have low cytotoxicity. The results illustrate that the nanocomposites have great potential as bimodal imaging agents for MR/CT. [ABSTRACT FROM AUTHOR]

Bimetallic Pt@Ir zigzag nanocomplexes were successfully synthesized with a uniform morphology via the simple reduction of Ir(acac)3 on the surface of Pt nanorods. The novel Pt@Ir nanocomplexes exhibited good catalytic activity in hydrogenation reactions under mild conditions, such as the hydrogenation of nitroaromatic compounds. The highest yield of the obtained product achieved was ∼99.9% using H2 as the sole reductant. [ABSTRACT FROM AUTHOR]

A novel, efficient, convenient and environmentally friendly approach for the synthesis of nitriles and imines from primary amines has been developed. Using commercially available red copper as the catalyst, ammonium bromide as the co-catalyst and molecular oxygen as the sole oxidant, nitriles and imines can be afforded in high yields through benzylic oxidation. [ABSTRACT FROM AUTHOR]

A new one-pot method has been developed for the selective synthesis of secondary amines via reductive amination of the corresponding nitriles using Pt nanowires as a catalyst. This method allows for the synthesis of both unsymmetrical and symmetrical secondary amines in excellent yields (up to 95%) in the presence or absence of additional amines, respectively. Furthermore, the reaction proceeds under mild conditions and is environmentally benign. [ABSTRACT FROM AUTHOR]

A novel one-pot method has been developed for the interfacial hydrogenation of nitriles to synthesize asymmetrical tertiary amines. The active Pt NWs allow for the preparation of a series of tertiary amines in excellent yields (up to 99.0%) and a mixed solvent is vital for the adjustment of the yield. And also, the reaction proceeded under mild conditions and is environmentally friendly.