Transfer hydrogenation of nitroarenes using cellulose filter paper-supported Pd/C by filtration as well as sealed methods

A reductive filter paper for selective nitro reduction has been prepared by modification of a pristine cellulose filter paper by Pd/C nanoparticles, as a portable catalyst. The reaction was performed in two different set-ups including (i) filtration and (ii) sealed systems, in the presence of ammonium formate and ex situ generated hydrogen gas reducing agents, respectively. In the sealed system in the presence of H₂ gas, the halogenated nitroarenes were completely reduced, while in the filtration system, different derivatives of the nitroarenes were selectively reduced to aryl amines. In both systems, the reduction of nitroarenes to aryl amines was performed with high efficiency and selectivity, comparable to a heterogeneous system. Reaction parameters were comprehensively designed using Design Expert software and then studied. The properties of the catalytic filter paper were studied in detail from the points of view of swellability, shrinkage, reusability, and stability against acidic, alkaline, and oxidative reagents.

A novel and efficient catalytic filtration has been developed for the selective reduction of nitro compounds on a Pd/C-doped cellulose filter paper.

Nickel carbide (Ni3C) nanoparticles for catalytic hydrogenation of model compounds in solvent

Nickel carbide nanoparticles (Ni3C) synthesized in high-boiling point solvent are used as colloidal catalysts for the hydrogenation of polar groups and hydrocarbons. They are stable under operating conditions (100 °C, 7 bar H2).

Threonine dehydratase enhances bacterial cadmium resistance via driving cysteine desulfuration and biomineralization of cadmium sulfide nanocrystals

Biomineralization is often used by microorganisms to sequester heavy metal ions and provides a potential means for remediating increasing levels of heavy metal pollution. Bacteria have been shown to utilize cysteine for the biomineralization of metal sulfide. Indeed, in the present study, the supplement of L-cysteine was found to significantly improve both cadmium resistance and removal abilities of a deep-sea bacterium Pseudomonas stutzeri 273 through cadmium sulfide (CdS) nanoparticle biomineralization. With a proteomic approach, threonine dehydratase of P. stutzeri 273 (psTD) was proposed to be a key factor enhancing bacterial cadmium resistance through catalyzing L-cysteine desulfuration, H₂S generation and CdS nanoparticle biomineralization. Consistently, deletion of the gene encoding psTD in P. stutzeri 273 resulted in the decline of H₂S generation, decrease of cadmium resistance, and reduction of cadmium removal ability, confirming the unique function of psTD directing the formation of CdS nanoparticles. Correspondingly, the single-enzyme biomineralization of CdS nanoparticle driven by psTD was further developed, and psTD was shown to act as a capping reagent for the mineralization reaction, which controlling the size and structure of nanocrystals. Our results provide important clues for the construction of engineered bacteria for cadmium bioremediation and widen the synthesis methods of nanomaterials.

Facile synthesis of hierarchical Ni7S6 and Co(ii)-doped Ni7S6 flower structures for high-performance supercapacitors

The as-prepared flower-like Ni₇S₆ structure with abundant surface active sites demonstrated good supercapacitor performance in an alkaline solution.

Wurtzite CuNi2InS4 Nanocrystals: A Quaternary Chalcogenide Magnetic Semiconductor

For the first time, quaternary chalcogenide CuNi₂InS₄ nanocrystals with a wurtzite structure have been designed and fabricated as a new magnetic semiconductor. The phase structure analysis suggests that the synthesized wurtzite CuNi₂InS₄ phase has a disordered structure in which Cu⁺, Ni²⁺, and In³⁺ ions share the same lattice site of the unit cell with a random cation distribution. The prepared CuNi₂InS₄ nanocrystals have uniform bullet-like morphology, small size distribution, good monodispersity, and high crystallinity. The magnetic properties investigation reveals that the wurtzite CuNi₂InS₄ nanocrystals can exhibit a weak ferromagnetic moment with the blocking temperature at around 13 K thanks to the disordered wurtzite structure and the high content of magnetic Ni²⁺ ions. As for the semiconducting properties, the as-obtained wurtzite CuNi₂InS₄ nanocrystals show a strong and broad visible light absorption and have a direct bandgap of 1.45 eV. Due to their favorable optical properties, the fabricated thin film of CuNi₂InS₄ nanocrystals exhibits a good photoelectric response to the solar spectrum, which makes the obtained new phase potential candidate for applications in the photovoltaics. This work demonstrates a new metastable I-II₂-III-VI₄ chalcogenide that can be used to render multiple functionalities and applications.

An in situ Bi-decorated BiOBr photocatalyst for synchronously treating multiple antibiotics in water

Currently, there is an urgent demand for developing new materials to remove antibiotics in the water environment, especially for the simultaneous degradation of multiple antibiotics. Here, we fabricated a novel Bi/BiOBr heterostructure via an in situ solvothermal strategy, and it exhibited excellent visible-light-responsive photocatalytic activity for synchronously removing multiple antibiotics coexisting in water. The Bi nanoparticles could extend the light absorption spectra of the sample and further facilitate electron-hole pair separation. The in-depth electron spin resonance (ESR) results confirm that the active species in Bi/BiOBr are holes (h⁺) and superoxide radicals (·O₂ ^-) under irradiation, and it is also proved that Bi could selectively reduce the formation of ·O₂ ^- in the BiOBr matrix. The coexisting system of TC (tetracycline hydrochloride), CIP (ciprofloxacin) and DOX (doxycycline) could be simultaneously photodegraded to approximately 0% within 30 min by the Bi/BiOBr photocatalyst.

Reduction of Nitro Compounds Using 3d-Non-Noble Metal Catalysts

The reduction of nitro compounds to the corresponding amines is one of the most utilized catalytic processes in the fine and bulk chemical industry. The latest development of catalysts with cheap metals like Fe, Co, Ni, and Cu has led to their tremendous achievements over the last years prompting their greater application as "standard" catalysts. In this review, we will comprehensively discuss the use of homogeneous and heterogeneous catalysts based on non-noble 3d-metals for the reduction of nitro compounds using various reductants. The different systems will be revised considering both the catalytic performances and synthetic aspects highlighting also their advantages and disadvantages.

Enzymeless biosensor based on β-NiS@rGO/Au nanocomposites for simultaneous detection of ascorbic acid, epinephrine and uric acid

In this study, marigold flower-like self-assembled β-NiS (nickel sulfide) nanosheets were grown on rGO (reduced graphene oxide) by a single-step hydrothermal process and then gold nanospheres (AuNS) were electrochemically deposited on the β-NiS@rGO nanostructures.

Graphene-like nanocomposites anchored by Ni3S2 slices for Li-ion storage

A facile route is employed to construct thin Ni₃S₂ nanoslices anchored by 2D RGO-based carbon, which can be used as high-performance LIB anode owing to the 2D structures facilitate to the electron transport and rapid Li⁺ diffusion.

Facile hydrothermal synthesis of NiS hollow microspheres with mesoporous shells for high-performance supercapacitors

Hollow NiS microspheres with excellent capacitive performance were prepared by a facile hydrothermal route without any surfactant or template.

Cotton-Textile-Enabled, Flexible Lithium-Ion Batteries with Enhanced Capacity and Extended Lifespan

Activated cotton textile (ACT) with porous tubular fibers embedded with NiS2 nanobowls and wrapped with conductive graphene sheets (ACT/NiS2-graphene) was fabricated by a simple two-step heat treatment method. When used as a binder-free electrode, the ACT/NiS2-graphene electrode exhibited an exceptional electrochemical performance including ultrahigh initial discharge capacity (∼1710 mAh g(-1) at 0.01 C), magnificent rate performance (the discharge capacitance retained at ∼645 mAh g(-1) at 1 C after 100 cycles) and excellent cyclic stability (the discharge capacitance recovered to ∼1016 mAh g(-1) at 0.1 C after 400 cycles).

A Non-sulfided flower-like Ni-PTA Catalyst that Enhances the Hydrotreatment Efficiency of Plant Oil to Produce Green Diesel

The development of a novel non-sulfided catalyst with high activity for the hydrotreatment processing of plant oils, is of high interest as a way to improve the efficient production of renewable diesel. To attempt to develop such a catalyst, we first synthesized a high activity flower-like Ni-PTA catalyst used in the hydrotreatment processes of plant oils. The obtained catalyst was characterized with SEM, EDX, HRTEM, BET, XRD, H₂-TPR, XPS and TGA. A probable formation mechanism of flower-like Ni(OH)₂ is proposed on the basis of a range of contrasting experiments. The results of GC showed that the conversion yield of Jatropha oil was 98.95%, and the selectivity of C11-C18 alkanes was 70.93% at 360 °C, 3 MPa, and 15 h⁻¹. The activity of this flower-like Ni-PTA catalyst was more than 15 times higher than those of the conventional Ni-PTA/Al₂O₃ catalysts. Additionally, the flower-like Ni-PTA catalyst exhibited good stability during the process of plant oil hydrotreatment.

Magnetically recoverable Ni/C catalysts with hierarchical structure and high-stability for selective hydrogenation of nitroarenes

A magnetic Ni/C catalyst with hierarchical structure has been synthesized and exhibits a high stability for selective hydrogenation of nitroarenes.

Facile construction of graphene-like Ni3S2 nanosheets through the hydrothermally assisted sulfurization of nickel foam and their application as self-supported electrodes for supercapacitors

A facile and low-cost approach has been developed for the fabrication of large-area nickel sulfide nanosheets via the hydrothermally assisted sulfurization of Ni foam.

Nanostructured metal sulfides for energy storage

Advanced electrodes with a high energy density at high power are urgently needed for high-performance energy storage devices, including lithium-ion batteries (LIBs) and supercapacitors (SCs), to fulfil the requirements of future electrochemical power sources for applications such as in hybrid electric/plug-in-hybrid (HEV/PHEV) vehicles. Metal sulfides with unique physical and chemical properties, as well as high specific capacity/capacitance, which are typically multiple times higher than that of the carbon/graphite-based materials, are currently studied as promising electrode materials. However, the implementation of these sulfide electrodes in practical applications is hindered by their inferior rate performance and cycling stability. Nanostructures offering the advantages of high surface-to-volume ratios, favourable transport properties, and high freedom for the volume change upon ion insertion/extraction and other reactions, present an opportunity to build next-generation LIBs and SCs. Thus, the development of novel concepts in material research to achieve new nanostructures paves the way for improved electrochemical performance. Herein, we summarize recent advances in nanostructured metal sulfides, such as iron sulfides, copper sulfides, cobalt sulfides, nickel sulfides, manganese sulfides, molybdenum sulfides, tin sulfides, with zero-, one-, two-, and three-dimensional morphologies for LIB and SC applications. In addition, the recently emerged concept of incorporating conductive matrices, especially graphene, with metal sulfide nanomaterials will also be highlighted. Finally, some remarks are made on the challenges and perspectives for the future development of metal sulfide-based LIB and SC devices.

Evolution of nickel sulfide hollow spheres through topotactic transformation

In this study, a topotactic transformation route was proposed to synthesize single-crystalline β-NiS hollow spheres with uniform phase and morphology evolving from polycrystalline α-NiS hollow spheres. Uniform polycrystalline α-NiS hollow spheres were firstly prepared with thiourea and glutathione as sulfur sources under hydrothermal conditions through the Kirkendall effect. By increasing the reaction temperature the polycrystalline α-NiS hollow spheres were transformed to uniform β-NiS hollow spheres. The β-NiS crystals obtained through the topotactic transformation route not only have unchanged morphology of hollow spheres but are also single-crystalline in nature. The as-prepared NiS hollow spheres display a good ability to remove the organic pollutant Congo red from water, which makes them have application potential in water treatment.

Solution-based synthesis and design of late transition metal chalcogenide materials for oxygen reduction reaction (ORR)

Late transition metal chalcogenide (LTMC) nanomaterials have been introduced as a promising Pt-free oxygen reduction reaction (ORR) electrocatalysts because of their low cost, good ORR activity, high methanol tolerance, and facile synthesis. Herein, an overview on the design and synthesis of LTMC nanomaterials by solution-based strategies is presented along with their ORR performances. Current solution-based synthetic approaches towards LTMC nanomaterials include a hydrothermal/solvothermal approach, single-source precursor approach, hot-injection approach, template-directed soft synthesis, and Kirkendall-effect-induced soft synthesis. Although the ORR activity and stability of LTMC nanomaterials are still far from what is needed for practical fuel-cell applications, much enhanced electrocatalytic performance can be expected. Recent advances have emphasized that decorating the surface of the LTMC nanostructures with other functional nanoparticles can lead to much better ORR catalytic activity. It is believed that new synthesis approaches to LTMCs, modification techniques of LTMCs, and LTMCs with desirable morphology, size, composition, and structures are expected to be developed in the future to satisfy the requirements of commercial fuel cells.