Search

The structural and magnetic properties were studied for recycling Nb-Fe-B powders from Nb-Fe-B sintered magnets sludge via reduction diffusion (RD) with calcium hydride (CaH2) particles. For comparison, traditional reducing agent calcium granules were applied to prepare recycled Nb-Fe-B powders. Finer particle size and better size distribution as well as lower impurity content are achieved by using CaH2 instead of Ca. In detail, the average particle size of the recycled Nb-Fe-B powder is reduced from 4.66 to 3.43 μm, and the bimodal distribution disappears. Moreover, the residual calcium content and oxygen content are reduced to about 0.080 wt% and 0.32 wt%. As a consequence, the room-temperature magnetization of the CaH2-recycled Nb-Fe-B powder is increased to 146.30 emu/g, 6.8% and 33% higher, respectively, than that of Ca-reduced powder and the initial sludge. Further analysis indicates that CaH2 is able to reduce the sludge at lower temperature to fabricate well-dispersed, uniform recycled powder with high magnetization arise from a combination factors of its low melting point, low thermodynamic behavior, and the release of hydrogen during the reaction.

A surfactant-free synthesis of precious metal nanoparticles performed in low boiling point solvents and in alkaline conditions has been reported recently. This strategy presents several advantages over alternative colloidal syntheses. The resulting nanoparticles are readily relevant for applications like catalysis and the synthetic process is compatible with large scale production. Alkaline mono-alcohols are here investigated as solvent and reducing agents to obtain colloidal Os nanoparticles by this low temperature (< 100 °C) surfactant-free synthesis. The effect of precursor (OsCl3 or H2OsCl6), precursor concentration (up to 100 mM), solvent (methanol or ethanol), presence or absence of base (NaOH) and addition of water (0 to 100 v.%) on the resulting nanomaterials is discussed. It is fond that no base is required to obtain Os nanoparticles as opposed to the case of Pt NPs for instance. The robustness of the synthesis for concentration of precursor up to 100 mM allows to perform X-ray total scattering with pair distribution function (PDF) analysis that shows that the 1-2 nm hcp NPs forms from chain-like [OsOxCly]-complexes.

VOCs, volatile organic compounds, which are mostly produced by the excessive emission of different industrial and commercial activities, pose a serious hazard to human health and primarily contribute to the creation of photochemical smog, which has a significant influence on air quality. The treatment of VOCs by catalytic oxidation at the lowest feasible temperature has been acknowledged as an efficient and cost-effective approach. Here, a novel catalyst with the platinum (Pt) nanoparticles confined in TiO2 nanotubes (TNT) by surface oxygen vacancy towards the catalytic combustion of ethylene has been prepared. Through the liquid-phase reduction strategy using sodium borohydride (NaBH4) as the reducing agent, the oxygen vacancies are effectively inserted onto the surface of TNT by regulating the reduction time, named as R-TNT. Subsequently, Pt was permitted to be trapped within R-TNT (Pt-in/R-TNT) via the vacuum assisted-impregnation method. The Pt nanoparticles confined in the TNT (Pt-in/TNT) could reduce the temperature down to about 175 °C for complete catalytic combustion of ethylene, a kind of VOCs, which was roughly 10 °C lower than the Pt nanoparticles loaded on TNT (Pt-out/TNT). More intriguing, the Pt-in/R-TNT displayed the highest catalytic activity and lowered the temperature by 20 °C. The X-ray photoelectron spectroscopy (XPS) and Ultraviolet–visible (UV–vis) measurements revealed that a saturation amount of oxygen vacancies were successfully introduced into TNT by reducing in NaBH4 solution. Based on the confinement effect of TNT, the formation of active oxygen species on the surface of TNT could further aggravate the electron density destitution inside TNT. Hence, the catalytic activity for Pt nanoparticles confined in R-TNT was significantly enhanced. A high-performance catalyst for removing VOCs is presented using an efficient confinement effect coupled with an electron modifier approach.

Nickel oxyhydroxide (NiOOH) is regarded as one of the promising cocatalysts to enhance the catalytic performance of photoanodes but suffers from serious interfacial charge-carrier recombination at the photoanode||NiOOH interface. In this work, surface-engineered BiVO4 photoanodes are fabricated by sandwiching an oxygen vacancy (Ovac) interlayer between BiVO4 and NiOOH. The surface Ovac interlayer is introduced on BiVO4 by a chemical reduction treatment using a mild reducing agent, sodium hypophosphite. The induced Ovac can alleviate the interfacial charge-carrier recombination at the BiVO4||NiOOH junction, resulting in efficient charge separation and transfer efficiencies, while an outer NiOOH layer is coated to prevent the Ovac layer from degradation. As a result, the as-prepared NiOOH-P-BiVO4 photoanode exhibits a high photocurrent density of 3.2 mA cm−2 at 1.23 V vs. RHE under the irradiation of 100 mW/cm2 AM 1.5G simulated sunlight, in comparison to those of bare BiVO4, P-BiVO4, and NiOOH-BiVO4 photoanodes (1.1, 2.1 and 2.3 mA cm−2, respectively). In addition to the superior photoactivity, the 5-h amperometric measurements illustrate improved stability of the surface-engineered NiOOH-P-BiVO4 photoanode. Our work showcases the feasibility of combining cocatalysts with Ovac, for improved photoactivity and stability of photoelectrodes.

Co–B has good catalytic activity in the hydrogenation reaction of unsaturated groups and has been widely studied and applied. Co–B catalysts were usually prepared by reducing cobalt salts with reducing agents. However, the high surface energy and magnetic properties of Co–B catalysts made the particles easily agglomerate. Then, agglomeration increased the particle size of the sample and reduced the effective surface area of the catalyst powder, which limited the catalytic activity of the Co–B catalysts. A new type of Co–B/copper nanowires/cetyl trimethyl ammonium bromide (Co–B/CuNWs/CTAB) catalyst with high catalytic activity was prepared by a chemical reduction in this work. The performance of Co–B/CuNWs/CTAB was studied in the hydrolysis of ammonia-borane (AB) and CuNWs inserted into the Co–B interlayer could avoid particle agglomeration, thereby effectively increasing the specific surface areas of the catalysts. Furthermore, the insertion of CuNWs facilitated the transportation of electrons and improved catalytic activity. The BET analysis shows that the maximum surface area of the sample is 148.9 m2/g. Meanwhile, the hydrogen generation rate of 13.46 L min−1·g−1 at 30 °C was obtained by using the synthesized Co–B/CuNWs/CTAB catalyst with a low activation energy of 8.771 kJ mol−1.

Coriandrum sativum and Allium sativumare belong to family alliaceae which is famous for its culinary and medicinal properties. These two sativum species’ seeds and cloves extracts are chosen to synthesize the cobalt oxide nanoparticles because it is eco- benign, secure as well as cost – effective method. The reducing sugar such as glucose which is present naturally in the extract used as reducing agent instead a harmful chemicals as reducing agent. The synthesized cobalt oxide nanoparticles using sativum species were characterization using UV–Visible spectroscopy, FT-IR spectroscopy, EDAX and SEM. The optical absorption spectrum for Co3O4 nanoparticles are studied using UV–Visible spectroscopy. The FT-IR spectrum confirms the presence of functional group in cobalt oxide nanoparticles. Scanning Electron Microscopy was employed to analyze the morphology, it shows that synthesized cobalt oxide nanoparticles show different morphology, which depends on the nature of the extract and of the compound present the extract. The EDAX studies show that the presence of cobalt and oxygen elements in the synthesized nanoparticles. Photo - catalytic activity of the synthesized nanoparticles was evaluated by degradation of Rhodamine B dye.

A high surface acidic ZrO2 nanoparticle was prepared using glucose as a non-toxic reducing agent. Palladium (Pd) nanoparticles in the range of 1–2 nm are grafted in in-situ as well as ex-situ via urea deposition over pre-synthesized ZrO2 nanoparticles. Both methods are found to be useful for the one-pot transformation of glucose to HMF, and their catalytic activities towards selective production of HMF are found to be strongly dependent on the particle size and nature of acidic sites. A linear-type activity trend is observed with Pd loading in reference to the HMF selectivity and presents the best catalytic performance. The activation energy and turnover frequency (TOF) of the 1–2 nm NP catalyst are further calculated to be 44.1 kJ mol−1 and 6.011 molHMF·molPd−1·h−1, respectively. Characterization of the spent catalysts indicates that smaller-sized NPs face severe agglomeration, resulting in poor stability and activity. Hence, the high catalytic performance can be attributed to the balance between Bronsted and Lewis acid sites, in combination with Pd species intrinsic activity. Due to their improved activity and stability, 2Pd–ZrO2in-situ exhibits 55% glucose conversion with 74.0% of HMF selectivity after 3h of reaction at 160 °C.

The inorganic calcium phosphate compound hydroxyapatite (HAP) is widely used in bone and teeth proxy applications in the biomedical field. The efficacy of this material depends on size and absolutely morphology. Synthesis of hydroxyapatite nanoparticles with appreciable size and morphology is considered as a significant technology. However, post-surgery bacterial infections were also accounted that could be a crucial and challengeable for a good biomaterial. To compensate, all issues, synthesis of Silver/Hydroxyapatite/Tryptophan nanocomposite was reported in the present study. Initially synthesis of silver nanoparticles (AgNPs) was done by the cost effective green method using the flower extract of Aerva lanata. The alkaloids, flavonoids, tannin and polyphenols present in the flower extract were acting as reducing agent for Ag ions. In the synthesis of HAP, Calcium Nitrate Tetrahydrate [CaNO3·4H2O] (0.05 M) and Diammonium Hydrogen Phosphate [(NH4)2 HPO4] were used as precursors and the amino acid tryptophan as a template. The as-synthesized silver nanoparticles, HAP/Tryptophan nanocomposite and Silver/HAP/Tryptophan nanocomposite were characterized by UV–Visible, FT-IR, XRD, SEM and antibacterial studies. All the results were authenticated that the Ag/HAP/Tryptophan nanocomposite can perform as a good biomaterial for bone and tooth replacement applications.

A simple novel green synthesis of the nano compound cerium oxide doped with zinc oxides (CeO2–ZnO) was produced with a reduction agent of glycosmis mauritiana leaf extracted. The compounds synthesized are characterized by × - ray diffraction, UV, DRS and TEM. The results show that the prepared materials were superior in performance as compared to unoped ZnO and CeO2 particles, due to alternation in band gap, surface adsorption and enhanced photoresponsive. The photocatalytic efficiency of the CeO2-ZnO series was evaluated against Acid black 1 and the antibacterial properties were checked against the clinical bacteria strains. All findings showed that CeO2-ZnOs' photocatalytical and antibacterial activities with various CeO2 material are superior to the pure ZnO activities.

Background Phosphogypsum is a waste product from production of phosphorus and is stored in a containment pond. Phosphogypsum wastewater still contains a usable amount of phosphorus. In addition to phosphorus, this water contains a small amount of arsenic, which prevents direct use of this water in agriculture. Method Recycling of phosphorus from phosphogypsum wastewater was performed by struvite (NH4MgPO4•6H2O), precipitation. Arsenostruvite (NH4MgAsO4•6H2O) has always occurred naturally in the presence of struvite. The properties of arsenostruvite in comparison with struvite were monitored. The effect of selected reductants (SnCl2, ascorbic acid, K2S2O5) on the potential of reducing the concentration of As in the struvite crystallized from phosphogypsum wastewater, was monitored. Findings When recovering phosphorus from phosphogypsum wastewater in the form of struvite the results showed that a ratio of As to P was lower by 50% compared to the original wastewater. K2S2O5 proved to be the most effective reducing agent for reducing the arsenic content of the product, but it was still not sufficient for the product to be used as a fertilizer without any further treatment.

The purpose of this study was to fabricate non-invasive transdermal patches loaded with promising greenly synthesized nanoparticles for breast cancer therapy. The half maximum inhibitory concentration (IC50) on triple negative breast cancer (TNBC) and human dermal fibroblast (HDF) cell lines were investigated. In addition, the migration inhibition of the cancerous cells was investigated as well. Moreover, the physicochemical properties (water uptake, thickness, weight, and content uniformity) of the patches were evaluated with the in-vitro release of the prepared nanoparticles from the patches. Carbopol was used as a film forming polymer, ethylene–vinyl acetate as a backing layer, while the root hair extract of Phoenix dactylifera was used as a reducing agent to form zinc oxide nanoparticles (ZnO NPs). Clear, transparent, and flexible transdermal patches were successfully synthesized with uniform thickness (0.25 ± 0.001 mm) and weight (0.42 ± 0.007 g). Patches showed ZnO NPs content uniformity of 91.74–94.40% with surface pH of 6.25 ± 0.02. They exhibited sustained release of ZnO NPs over 25 h with a steady-state flux of 7.21 µg/h/cm2. The particle size of ZnO NPs was 88.15 ± 4.99 nm, polydispersity index was 0.44 ± 0.26, and zeta potential was − 16.63 mV. Moreover, the cytotoxicity of ZnO NPs on the TNBC cell lines was dose dependent. Accordingly, it increased from 54 to 100% upon increasing ZnO NPs concentration from 0.16 to 2.5 µg/mL. The IC50 of ZnO NPs (0.42 µg/mL) on TNBC was significantly (p

Ferrovanadium nitride, which comprises V and N, is an important alloy additive for the production of high-strength low-alloy steel. As an efficient reducing agent and nitrogen source, ammonia gas is widely used in the preparation of metal nitrides. In this study, ferrovanadium nitride alloy powder is prepared by reducing and nitriding VO2/Fe2O3 in NH3–H2 gas mixtures with different nitriding potentials. Thermodynamic analysis indicate that the reduction and nitridation of VO2 and Fe2O3 is feasible. VO2 is converted into VN, whereas Fe and Fe4N can be formed depend on the reaction conditions. Lower temperatures and higher nitriding potentials are beneficial to the formation of Fe4N. Based on Rietveld refinement analysis, the formation of Fe4N and the atomic occupancy of V and N in vanadium oxynitride, which is associated with the temperature, reaction time, and nitriding potential, is determined. A ferrovanadium nitride alloy powder with an O content of 0.26 wt.% is prepared by reducing and nitriding VO2/Fe2O3 at 900 °C for 1 h at a nitriding potential of 4.4 × 10−3 Pa−0.5.

Gold (Au) and zinc oxide (ZnO) nanoparticles decorating reduced graphene oxide (RGO) was designed by hydrothermal method using the agent of 1,8 diamino, 3, 6 dioxaoctan (DDO). This novel DDO with triple function: reducing agent, capping agent and alkaline agent lead to the decoration of Au and ZnO on the RGO. Ternary nanohybrid of Au/ZnO/RGO are probed as photocatalysts for comparative photo-degradation study. The pollutant model of Rhodamine B with different concentrations and pH in the presence of diverse dosages of designed nanohybrids was tested in terms of photocatalyst degradation. Further, Au/ZnO/RGO nanohybrid delivered a good efficiency of 95.05 % at pH of 11 and dye concentration of 10 ppm in the presence of 0.06 g designed photocatalysts under visible light. The efficiency retention over 7 runs was 85.80%.

Steam iron process represents a technology for H2 production based on iron redox cycles. FexOy are reduced by syngas/carbon to iron, which is subsequently oxidized by steam to produce pure H2. However, the system shows low stability. In this work, the effect of promoters (Al2O3, MgO and CeO2) on FexOy stability is investigated (10 consecutive redox cycles). Bioethanol is used as a reducing agent. The particles are synthesized by coprecipitation method, analysed by BET, XRD, SEM and tested in a fixed bed reactor (675 °C, 1 bar). Pure H2 is obtained controlling the FexOy reduction degree feeding different amounts of ethanol (4.56–1.14 mmol) until no CO is detected in oxidation. The results show that the promoters not only improve the thermal stability of FexOy but also affect its redox activity and react with iron forming spinel structures. MgO led to the highest activity and cyclability (H2 = 0.15 NL; E = 35%).

Introduction and Aim:Emergence of different applications of metallic nanoparticles in various field leads to innovation of new synthetic strategies. Besides being non-toxic to mammalian cells, zinc oxide nanoparticles (ZnONPs) has gained paramount attention due to its excellent antibacterial potential. This study illustrates a comparative analysis of antibacterial and cytotoxic activity of both phytochemically synthesized and chemically synthesized commercially available ZnONPs. Materials and Methods:As a source of reducing agent, leaf extract of Coriander sativum was employed in case of green synthesis of ZnONPs. Several techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Dynamic light Scattering (DLS) and Field emission Scanning Electron Microscopy (FESEM) were performed to characterize both green synthesized and commercial ZnONPs.Antibacterial potential of both theZnONPs were investigated on Gram-positive and Gram-negative bacterial strains to draw a correlative outcome. Hepatocellular cell line was used to determine the cytotoxic activity of both ZnONPs. Results:Both the nanoparticles showed antibacterial and cytotoxic activity with measurable degree of difference. Conclusion: From these studies it can be concluded, the green synthesized nanoparticles showed greater antibacterial as well as cytotoxic activity in comparison to the commercial ZnONPs.

Among diverse metal nanoparticles, palladium nanoparticles (PdNPs) have captured the special attention of researchers because of their unique applications. However, the synthesis of PdNPs by conventional procedures incorporates harmful solvents, reducing agents, and produces toxic pollutants and by-products. The plant part extract-assisted green synthesis of palladium nanoparticles has been known as the best solution to minimize the limitations of conventional methods. Bio synthesized nanoparticles have good selectivity and catalytic properties. Thus, they have been investigated as nanocatalysts in numerous catalyst based reactions. In this review article, we have explored the various plant parts responsible for the bioreduction of palladium ions, characterization of PdNPs and heterogeneous catalytic activity of PdNPs in the C–C coupling reaction. In addition, we reviewed a plausible mechanist approach for the fabrication of PdNPs.

Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft" copper(I) hydrides to previously unreactive "hard" ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.

The interaction of isomeric dinitrobenzenes (DNBs) with titanium(III), tin(II), and vanadium(II) chlorides, which are reducing agents used as electron carriers in the electrosynthesis of diaminobenzenes, has been studied. Rate constants of the reduction of isomeric DNBs and nitrophenylhydroxylamines by SnCl2 and TiCl3 in a 2 M water-alcohol solution (10 vol.% C2H5OH) of HCl were measured, and activation energies of the reduction of isomeric DNBs were determined. The rates of interaction of DNBs with the listed mediators increase in the series SnCl2 < TiCl3 < VCl2. It is shown that the electrolysis of DNBs in the presence of an excess of these mediators makes it possible to obtain the corresponding diaminobenzenes with a yield of 60–90%.

Typically, industrial electroless copper plating solutions use formaldehyde as a reducing agent. However, since formaldehyde has a strong odor and is a carcinogenic substance, it has an adverse effect on the working environment and the human body. Therefore, an electro-less copper plating solution containing no formaldehyde is desired. We have researched and developed a formaldehyde-free electro-less copper plating solution and evaluated its properties for applications such as panel level package (PLP). Price is the main reason for selecting agents with reducing power to copper for use in the plating market. We promoted to develop the plating solution using sodium hypophosphite as a reducing agent, which is the next least expensive after formalin solution. The reducing agent used in this plating solution has low catalytic activity for copper. As a result, when the palladium catalyst on the resin is covered with copper plating, the plating deposition rate is reduced. In order to prevent the deposition reaction from stopping during plating, a metal salt with high catalytic activity for this reducing agent is plated. The method of adding to the liquid was carried out. As a result, the bath stability of the development bath is excellent because no Cannizzaro reaction or disproportionate reaction of the first copper ion occurs, unlike ordinary electro-less copper plating solutions. This is a major advantage in terms of running costs and requirements for ancillary the plating equipment. When the characteristics of the plating film by development bath were examined, the internal stress was found to be as low as 150 MPa on the tensile side. The adhesion to the ABF resin was high, ranging from 500 to 700 gf/cm. Also it exhibits excellent plating deposition inside blind via hole (BVH) which is equivalent to that of general electro-less copper plating solution, it can be applied to semi-additive process package boards where electro-less copper plating film is etched.

Activation of a nickel-chromium catalyst for low temperature steam reforming of C2+-alkanes to methane rich gas has been studied by TPR and XRD in situ techniques. The activation procedure has been studied with the following reducing agents: hydrogen, syngas, methanol and the reaction mixture of low-temperature steam reforming. Attempts were made to activate the catalyst at 300, 340 and 420 °C. Activated samples were tested in low-temperature steam reforming of a methane-propane mixture. A passivation process has been proposed and tested for compatibility with following activation in the LTSR reaction mixture.

To enhance the remediation efficiency of arsenic (As) and chromium (Cr)co-contaminated soil, the effect of various combinations of reducing and chelating agents on the removal of As and Cr was studied in the present work by using electrokinetic technology coupled with a permeable reactive barrier (EK-PRB). In an experiment with EK-PRB, reducing agents (ascorbic acid and citric acid) and chelating agents (EDTA-2Na) were applied together with CaAl-layered double hydroxide (CaAl-LDH) to pretreat As and Cr co-contaminated soil. The chelating agents increased the removal efficiency of As and Cr, while the reducing agent only improved As removal in co-contaminated soil. The best removal efficiencies of As and Cr were 41.2% and 46.8%, respectively. The reducing agents promoted the production of As(III) and enhanced the migration of As. However, a large amount of Cr(VI) was reduced to Cr(III), which affected the migration of Cr. Although the addition of chelating agents partly increased the migration of Cr(III), the removal of total chromium (TCr) still decreased. In this remediation system, a PRB can effectively capture and fix As and Cr. The results indicated that As was mainly adsorbed on the surface of CaAl-LDH, while the surface adsorption and intercalation of CaAl-LDH were the main mechanisms for Cr.

Antigen-bearing proteins become progressively unavailable to immunodetection after prolonged storage of routine sections, exposed to a variety of agents, such as moisture, oxygen, and temperature. By proteomic analysis, the antigens are retained in the sections and definitely in the tissue block, pointing to fixation-independent, storage time–dependent protein modifications. Based on previous experience, we hypothesized that a combined exposure to a reducing agent and to chemicals favoring protein conformation changes would reverse the masking in aged sections. Disaccharides, lactose and sucrose, and a surfactant, added to a standard antigen retrieval buffer, reverse the negative changes in aged sections. Furthermore, they provide enhanced access to antigens in freshly cut sections, but not universally, revealing additional factors, besides heat and calcium chelation, required for antigen retrieval of individual proteins

The leaching of manganese (Mn) ore in sulphuric acid (H2SO4) under reductive conditions has been studied. The effects of leaching parameters such as ore/reductant mass ratio, acid concentration, ore particle size, solid/liquid ratio, leaching time and different reductant potential on the maximum recovery of manganese have been investigated. The optimal leaching conditions were ore/reductant mass ratio of 1:3.4, acid concentration of 10% v/v H2SO4, ore particle size of 63-200 µm, particle size of iron powder of –150 µm, solid/liquid ratio of 1:20, and leaching time of 1.5 hours at room temperature. A comparative analysis on the recovery of manganese ore was also investigated under the optimal leaching conditions for two different reductants, iron sulphate (FeSO4) and iron powder. The maximum manganese recoveries at the optimal leaching conditions in the presence of FeSO4 and iron powder are 80.6% and 95%, respectively. The results indicate that manganese can readily be leached during short time at room temperature. Furthermore, iron powder has a stronger reducing power compared to FeSO4 with respect to manganese ore recovery.

An assessment of the possibility of steel direct microalloying with cerium was performed using thermodynamic modeling of cerium reduction from slags of CaO– SiO2– Ce2O3 system containing 15 % Al2O3 and 8 % МgO, additional additives of reducing agents (aluminum or ferrosilicoaluminium), at temperatures of 1550 and 1650 °C using the HSC 6.1 Chemistry (Outokumpu) software package. Depending on the additional additives of aluminum or ferroglycoaluminium, metal temperature, slag basicity and content of cerium oxide, 0.228 to 40.5 ppm of cerium transfers into the metal. With an additional additive of aluminum from slag (Y1) containing 1.0 % of cerium oxide, 0.228 ppm of cerium is transferred to the metal at 1550 °C. An increase in the system temperature to 1650 °C is accompanied by a slight increase in cerium content, reaching no more than 0.323 ppm. When added to ferrosilicoaluminium metal, cerium content in the metal is higher and amounts to 0.402 and 0.566 ppm at 1550 and 1650 °C, respectively. When concentration of cerium oxide in the slag (Y2) increases to 7.0 %, more signifcant increase in cerium content in the metal is observed, reaching in temperature range of 1550 – 1650 °C, 1.65 – 2.31 ppm with aluminum additives and 2.90 – 4.05 ppm with ferrosilicoaluminium additives. The most noticeable increase in cerium content in the metal is observed with an increase in slag basicity. During formation of slags with basicity of 2 – 3, containing 1 – 7 % Ce2O3, the equilibrium concentration of cerium in the metal varies from 0.5 to 4 ppm with aluminum additives and 1 – 7 ppm with ferro­silicoaluminium additives at 1550 °C. Slags transfer to the increased (up to 3 – 5) basicity is accompanied by an increase in the equilibrium content of cerium in the metal to 4 – 12 ppm with aluminum additives and 7 – 20 ppm with ferrosilicoaluminium additives at Ce2O3 content of 3 – 7 % and, as a result, an increase in efciency of cerium reduction process.

Tungstenite of unusual shapes (spheroids, rings, threads, spirals, etc.) was found in scheelite of gold-bearing quartz–carbonate–pyrite–chalcopyrite veins. It is crystallized in the veins in the final part of mineral deposition, after crystallization of sulfides, sulfosalts, and scheelite of several generations against the background of decreasing activity of sulfur. The issue concerning the type of the strong reducing agent of the W6+ → W4+reaction rarely occurring in nature is crucial for the formation of tungstenite. There are no traces of reducing agents, which could be solid or liquid hydrocarbons, in the veins. The unusual shapes of tungstenite aggregates similar to biomorphosеs may be evidence of the existence of microorganisms in the fractured anisotropic medium in scheelite at the boundary of the transition of the quartz part of the vein to the substantially carbonate part. The occurrence of the biomorphоsеs only in scheelite suggests that microorganisms have a W-dependent metabolism, which is observed in extremophiles of the Archaea domain producing a strong reducing agent H2; methanogens producing CH4 coexist in symbiosis with them.

The paper presents the thermodynamic modeling results of zinc and iron reduction from B2O3 ‒ CaO ‒ Fe2O3 ‒ ZnО melts by CO ‒ CO2 and H2 ‒ H2O mixtures containing 0 – 60 % CO2 (H2O) at 1273 – 1673 K using a technique describing the reduction of metals from an oxide melt by gas in bubbling processes, under conditions that provide an approximation to real systems. Its originality is equilibrium determination for each individual portion of gas supplied into the working fluid. The reducible metals oxides content in each calculation cycle is taken from the previous data. During the calculations, changes in the content of zinc (СZnO ) and iron (СFe2O3 , СFe3O4 and СFeO ) oxides in the melt and the degree of their reduction were estimated. When using CO or H2 as a reducing agent, this process proceeds in three stages. In the first stage, Fe2O3 is reduced to Fe3O4 and FeO. CFe2O3 values decrease to almost zero, while CFe3O4 and CFeO increase simultaneously. By the end of the stage, СFe3O4 reaches its maximum value. At the second stage, the Fe3O4 → FeO transition occurs, when СFeO values reach its maximum. At these stages, there is a slight increase in the CZnO . At the third stage, the values CFeO and CZnO decrease, and iron and zinc are reduced. An increase in temperature dramatically reduces the gas consumption for zinc reduction by 2 – 3 times, and the replacement of CO with H2 reduces it by less than 20 %. In the presence of oxidizing agents (CO or H2O), only zinc is reduced. The process ends when the final content of zinc oxide in the melt corresponds to the equilibrium with the initial gas composition. The higher the temperature, the less CZnO is. The obtained data are useful for the development of technologies for the selective recovery of metals.

Nanoparticle synthesis is an important area of nanotechnology and has been performed by undergraduate students frpm various universities across the globe. Due to the availability of massive data on the synthesis of a wide variety of metallic nanoparticles, including silver, gold, selenium, zinc, copper, iron, palladium, platinum, titanium, etc., and their oxides, it has become tedious to select an ideal and workable protocol for their synthesis. Herein, we have focused on the standardized chemical and biological methodologies to prepare selenium nanoparticles (SeNPs or nanoselenium). Chemical methods exploit chemicals such as sodium selenite (Na2SeO3) and reductants (l-ascorbic acid, glutathione, etc.), along with stabilizing agents (Polysorbate 20, protic acid, lysozyme). Although these methods have been used for commercial purposes, they suffer from several drawbacks such as the use of excessive additives for controlled morphology, multistep synthesis, high running cost, and environmental toxicity. Biogenic synthesis using plant materials and microorganisms (algae, fungi, yeast, bacteria, and viruses), on the other hand, is a sustainable, environment-friendly, and cost-effective approach. The natural reducing agents facilitate the conversion of selenium salts into nanosized selenium particles in a single step and act as capping and stabilizing agents, which impart synergism in biological activities. Physical methods such as hydrothermal, irradiation, pulsed laser ablation, etc., have also been used for their production; however, high cost, stringent conditions, and high energy consumption have hampered their applications. Herein, we present a step-by-step methodology using chemical and biological reducing agents to synthesize selenium nanoparticles which will assist the undergraduate learners in selecting a well-tested method based on the conditions of an experiment and desired applications.

An1.33T4Al8Si2 (An = Ce, Th, U, Np; T = Ni, Co) were synthesized in metal flux reactions carried out in aluminum/gallium melts. In previous work, U1.33T4Al8Si2 (T = Co, Ni) analogues were formed by arc-melting U:T:Si and reacting this mixture in Al/Ga flux. However, in the current work, all compounds were synthesized by using AnO2 reactants, taking advantage of the ability of the aluminum in the flux to act as both solvent and reducing agent. While reactions with T = Co yielded hexagonal Gd1.33Fe4Si10-type quaternary phases for all An, reactions with T = Ni produced these compounds only with An = U and Np. For reactions with An = Ce and Th, the reactions led instead to the formation of AnNi3-xSixAl4-yGay phases, with the tetragonal KCu3S4 structure type. Attempts to synthesize plutonium analogues Pu1.33T4Al8Si2 were also unsuccessful, producing the previously reported PuCoGa5 and Pu2Ni5Si6 instead. Magnetic data collected on the neptunium analogues Np1.33T4Al8Si2 (T = Ni, Co) show antiferromagnetic coupling at low temperatures and indicate a tetravalent state for the Np ions.

This article presents the results of research on the development of an effective technology for the production of non-fired pellets using a binder additive and a reducing agent. The proposed method will make it possible to obtain pellets using material of class 0-5 mm, i.e. eliminates the costliest part of the pellet production technology - regrinding. It is also important that the non-fired agglomeration of the material almost unchanged the composition and properties of the feedstock, as a result of which the reduction processes in them begin earlier and proceed more intensively. Using the results of physical and chemical studies, a technology has been developed for pelletizing fines of manganese ore from the Western Kamys deposit using clay from the Sazdinsky deposit as a binder and smelting ferrosilicon manganese using manganese pellets.

A green deposition method of zinc oxide nanoparticles using coffee leaf extraction was successfully prepared. The use of these preparation techniques is accepted by many researchers because it is nonexpensive and simple and has no environmental impact during the operation. The determination and reduction of Zn ions to ZnO NPs were characterized by using a UV-visible spectroscope. The UV-visible spectroscopy result reveals that the large band gap energy is observed in the visible region at the wavelength of 300 nm. X-ray diffraction and SEM analysis confirm that the deposited nanoparticle is highly crystalline with (111), (222), and (100) planes and cubic shape structure. The coffee leaf extraction serves as a reducing agent for stability of the particle length, where its medicinal value outcome showed an important antibacteria of the pathogenic type which appeared on the wound. The present research deals with the green synthesis of ZnO NPs as well as its application in toxicity reduction.

In this research work, a simple, one-step and environmentally friendly method is reported for synthesizing metallic Co nanoparticles (NPs) and its application in Fischer–Tropsch Synthesis. In this attractive method, metallic CoNPs decorated on the alumina surface are prepared by auto-reduction of cobalt (II) formate dihydrate at 380 °C for 4 h under high-pure nitrogen atmosphere. During the thermal decomposition process, hydrogen and carbon monoxide gases, which are reducing agents, are released. The decomposed samples were directly used in the reaction without typical hydrogen pretreatment. For comparison, the Co/γ-Al2O3 catalyst was also prepared by the traditional impregnation method, which includes the calcination and reduction steps. Different characterization techniques including TGA-DTA, XRD, FESEM, EDX mapping and BET were carried out to investigate the structural and textural properties of samples. CO conversion of the auto-reduced Co/γ-Al2O3 catalyst was almost twofold of the reduced catalyst by H2. The characterization data indicated that auto-reduction method leads to better dispersion and smaller CoNPs production than those prepared by H2 reduction pretreatment. Therefore, the active sites for the reaction increased, leading to an increase in CO conversion. The results suggested that the catalyst reduction under H2 stream is unnecessary.

S-MnO2, Cl-MnO2, and Ac-MnO2 samples were prepared by redox method with the oxidant (KMnO4) and the reducing agent precursors [MnSO4, MnCl2 and Mn(Ac)2]. This work studied the influence of the precursors on the catalytic performance. Ac-MnO2 was aminated and doped with graphene to obtain the modified manganese-based catalyst MnO2-NH2-GO. XRD, Raman, FTIR, XPS, NH3-TPD, CV (cyclic voltammetry) were used to characterize the catalyst. The average oxidation state (AOS) of Mn element was also calculated. The results of the catalytic ozonation quinoline degradation experiment shown that the four catalysts was ranked as follows: S-MnO2

AlH3 (PPh3 )2 was synthesized as a stable solid being the first known 1 : 2 alane arylphosphane adduct. Although only weakly intra-molecularly coordinated, it displays as a molecular crystal significant inertness against atmospheric humidity and oxygen due to strong steric screening of the alane unit. The compound readily dissociates PPh3 in solution allowing for its use as a Lewis acidic reducing agent. These features lead to an easy to store, easy to use reducing agent that may enable the quantitative investigation of aluminum hydride chemistry including reduction, complexation and hydroalumination reactions. The structure contains two non-equivalent penta-coordinated aluminum centers that despite long Al-P distances of ca. 2.7 A display unusually high quadrupolar coupling constants CQ of 25.1 and 26.5 in 27 Al solid state NMR measurements. The product was also tested as a reducing agent on a small set of selected compounds with various functional groups.

The fast progress of lab-scale perovskite solar cells makes the problem of upscaling of perovskite thin-film deposition more and more acute; therefore, the development of new methods for perovskite deposition is highly desired. In this work, we proposed a new solution-free preparation approach for hybrid perovskite films based on the in situ generation of methylammonium iodide from methylamine and iodine vapors in the presence of an organic reducing agent conjugated with a redox process of metallic lead conversion with iodine vapor. At first, we demonstrated that either metallic lead or lead iodide powders can readily react with the solution of methylamine and iodine in the presence of isopropyl alcohol acting as a reducing agent, resulting in a phase-pure polycrystalline CH3NH3PbI3 perovskite. A possible mechanism of underlying chemical processes has been proposed. In order to convert the predeposited thin films of metallic lead to CH3NH3PbI3 perovskite, a protocol of sequential treatment by iodine and methylamine vapors was proposed. Finally, we revealed the optimal conditions of processing, which were proven to be facile and robust for the sake of the better control of perovskite grain morphology.

Abstract Selenium nanoparticles (SeNPs) have the potential to be used for various applications. Therefore, they have attracted more attention in recent years and several synthesis methods have been exploited. Green synthesis using plant extracts has gained popularity because it requires non-toxic solvents and moderate temperatures. Furthermore, it is environmentally friendly and uses a reducing agent that is easily accessible and biodegradable. In this review, we present recent reports concerning the capability of different plant materials for the biosynthesis of selenium nanoparticles. The synthesis conditions (temperature, time, selenium precursor, and extract concentration) are discussed in combination with the characteristics of the obtained product (composition, size, shape, stability). The application of synthesized selenium nanoparticles was briefly presented. Graphic abstract

In the present paper we report a novel synthesis method of silicon quantum dots (SiQDs) using 3-Aminopropyltriethoxysilane (APTES) as silicon precursor and low molecular weight chitosan (CS) as reducing agent. The obtained SiQDs have a hydrodynamic diameter of 2.3 nm, water dispersible, presents blue emission band at 434.5 nm (2.85 eV) with a Commission Internationale de l’Eclairage 1931 (CIE1931) chromaticity coordinates (x = 0.1665, y = 0.1222), the experimental absorbance of the SiQDS was measured and the band gap (Eg) was estimated through PerkinElmer’s method, the obtained value was 3.1 eV and a positive ζ-potential of + 35 mV, resulting in photonics, microelectronics, and biotechnological potential applications.

The purposes of this study are to reduce Fe2O3 using hydrogen (H2) and carbon monoxide (CO) gases at a high temperature zone (500 °C–900 °C) by focusing on the influence of reduction gas concentrations. Reduction behavior of hematite (Fe2O3) at high temperature was examined using temperature programmed reduction (TPR) under non-isothermal conditions with the presence of 10% H2/N2, 20% H2/N2, 10% CO/N2, 20% CO/N2 and 40% CO/N2. The TPRCO results indicated that the first and second reduction peaks of Fe2O3 at a temperature below 660 °C appeared rapidly when compared to TPRH2. However, TPRH2 exhibited a better reduction in which Fe2O3 entirely reduced to Fe at temperature 800 °C (20% H2) without any remaining of wustite (FeO) whereas a temperature above 900 °C is needed for a complete reduction in 10% H2/N2, 10% and 20% CO/N2. Furthermore, the reduction of hematite could be improved when increasing CO and H2 concentrations since reduction profiles were shifted to a lower temperature. Thermodynamic calculation has shown that enthalpy change of reaction (ΔHr) for all phases transformation in CO atmosphere is significantly lower than in H2. This disclosed that CO is the best reductant as it is a more exothermic, more spontaneous reaction and able to initiate the reduction at a much lower temperature than H2 atmosphere. Nevertheless, the reduction of hematite using CO completed at a temperature slightly higher compared to H2. It is due to the presence of an additional carburization reaction which is a phase transformation of wustite to iron carbide (FeO → Fe3C). Carburization started at the end of the second stage reduction at 600 °C and 630 °C under 20% and 40% CO, respectively. Therefore, reduction by CO encouraged the formation of carbide, slower the reduction and completed at high temperature. XRD analysis disclosed the formation of austenite during the final stage of a reduction under further exposure with high CO concentration. Overall, less energy consumption needed during the first and second stages of reduction by CO, the formation of iron carbide and austenite were enhanced with the presence of higher CO concentration. Meanwhile, H2 has stimulated the formation of pure metallic iron (Fe), completed the reduction faster, considered as the strongest reducing agent than CO and these are effective at a higher temperature. Proposed iron phase transformation under different reducing agent concentrations are as followed: (a) 10% H2, 20% H2 and 10% C; Fe2O3 → Fe3O4 → FeO → Fe, (b) 20% CO; Fe2O3 → Fe3O4 → FeO → Fe3C → Fe and (c) 40% CO; Fe2O3 → Fe3O4 → FeO → Fe3C → Fe → F,C (austenite).

Zirconia supported palladium catalysts were synthesized in the inert solvent by an in-situ reduction route. The preparative parameters, such as the reducing agents and the way of pre-nucleation, were regulated for the purpose of tuning the interaction between the support and the active metal (SMI). When a high dispersion of palladium is obtained by reducing agent of 1,2-hexadecanediol, a strong SMI between the active metal and zirconia is built up. This depresses the catalytic performance of the Pd/PdOx composite active phase for methane combustion. Conversely, the ratio of palladium species (Pd/PdOx) is apt to be optimized in the case of sample reduced by 2,5-di-tert-butyl-p-diphenol (DTBHQ). Furthermore, the catalysts involved a pre-nucleation step will result in a much weaker SMI, which leads to a decrease of catalytic activity for methane combustion. It is proved that an appropriate SMI is a key factor for the oxidation activity of supported palladium catalysts. The reduction of palladium component by 2,5-di-tert-butyl-p-diphenol (DTBHQ) launched until 200 °C. This would result in an active phase (Pd/PdOx) with less strong metal-support interaction (SMSI). Therefore, the ignition temperature of the methane oxidation is lowered by 100 °C.

Cobalt (III) is present in most of the minerals in the Congolese Copperbelt deposits. Its hydrometallurgical treatment requires to be reduced to Co2+, using a reducing agent. Using the Principal Component Analysis (PCA) approach, a 16 × 7 matrix was built to identify groups of ores/reducers with similar metallurgical performance. The study was based on the optimum values of reducing agents for the four selected minerals: 1.34, 0.33, 1.51, 0.25 g for Fe2+; 0.63, 0.51, 0.47, 0.24 g for Na2S2O5; 0.37, 0.11, 0.34, 0.21 g for Fe; and 2.02, 0.07, 0.13, 0.16 g for Cu. These optima crossed with other variables retained, in particular, the Cu and Co yields, reducing agent consumption, Cu and Co solubilization, and redox potential at leaching completion were reduced to two main components F1 (41.38%) and F2 (31, 46%). It emerges from the application of Principal Component Analysis to the 16 × 7 matrix a correlation circle showing that the variables having a major influence on the solubilization of Co are the reducing agent consumption by Co (24.48%), the amount of reducing agent (20.14%), and the potential at reaction completion (18.61%). Homogeneous groups of ores/reducers with good performance quality (F1 + F2 = 72.84%) were identified. In all and from a performance perspective, the ores treated with Fe2+, Fe, and Cu gave satisfactory metallurgical results (> 95% yield). On the contrary, the use of Na2S2O5 on all the deposits gave lower results (between 90% and 95% Co).

The influence of mercury on the morphology and formation mechanism of gold amalgams in the presence of different reducing agents (ascorbic acid and sodium borohydride) was systematically studied. In the presence of cetyltrimethylammonium bromide (CTAB), chemical reducing agents not only reduced mercury ions in the solution but also replaced the CTAB molecules on the surface of the gold nanorod. The stability of the reducing agents in the colloidal system and the combining capacity of the reducing agent to the gold nanoparticles can affect the alloying process of mercury and gold, thereby forming a rod-shaped or spherical gold amalgam. Once CTAB was removed, a similar transformation process occurs between the gold nanorods and mercury. In addition, without the presence of a stabilizer, mercury that cannot be dispersed undergoes Ostwald ripening growth, which causes the gold amalgam nanoalloys to form a tip-to-tip structure as a result of mercury enrichment because of the weak shielding effects occurring at the tips of the gold nanorods. After the CTAB molecules were substituted with ascorbic acid and alkylthiol molecules, the question of whether the shielding effect weakened or disappeared was also investigated. By investigation, this research found that, in comparison to the blocking effect of CTAB molecules, the binding ability of the reducing agent to gold plays a dominant role in the nanoamalgam formation process.

Green synthesis of ZnO NPs with biological systems is becoming a growing field, especially in plant extracts nanotechnology. Biological reducing agents have been interpreted worldwide to lessen the impact of toxic chemicals applied in development of nanoparticles. In present research, work deals with green synthesis & characterization of ZnO NPs via Psidium guajava leaf extract, also to evaluate their antibacterial action against some selected bacteria. The preparation of ZnO NPs was attained via sol–gel assisted microwave irradiation process. The XRD pattern confirms the hexagonal phase of ZnO and crystalline size to be ~ 15.8 nm. FTIR analysis depicts the bio functional groups present in the surface of the ZnO nanoparticles, SEM predicts the size and morphology of the sample, and it shows rod-shaped surface. Then, the EDAX results showed the purity & elemental stoichiometry of the ZnO nanoparticles. Also, the UV was performed to investigate the optical nature of the prepared ZnO nanoparticles. Also, the antibacterial activity results revealed significantly inhibited both types of bacteria in higher concentrations. This study also suggests that green synthesized ZnO nanoparticles can an excellent antibacterial agent.

Reductive transformations of easily available oxidized matter are at the heart of synthetic manipulation and chemical valorization. The applications of catalytic hydrofunctionalization benefit from the use of liquid reducing agents and operationally facile setups. Metal‐catalyzed hydroborations provide a highly prolific platform for reductive valorizations of stable C=X electrophiles. Here, we report an especially facile, broad‐scope reduction of various functions including carbonyls, carboxylates, pyridines, carbodiimides, and carbonates under very mild conditions with the inexpensive pre‐catalyst Mn(hmds)2. The reaction could be successfully applied to depolymerizations., Mn(hmds)2 enables clean hydroborations of C=X electrophiles (nitriles, amides, esters, pyridines, carbonates, diimides) at 20–80 °C. The protocol was applied to polymer degradations (polyesters, polycarbonates) and CO2 reduction. Mechanistic studies indicate the catalytic role of MnII hydrides, for example, the isolated cluster [MnH(hmds)]6.

Green synthesis of selenium nanoparticles (Se-NPs) was done using Abelmoschus esculentus extract as the capping and reducing agent and sodium selenite (Na2SeO3) as the selenium source. UV-Vis spect...

Detection of uric acid (UA) is inevitable today, as very less amount of uric acid in human leads to Fanconi Syndrome, Wilson’s disease and cardiovascular disorders. Here, we report an eco-friendly synthesis of a nitrogen-doped carbon dot/Chromium (VI) [N–C dot/Cr (VI)] fluorescent nanoprobe for nanomolar detection of uric acid. N–C dot/Cr (VI) nanoprobe is synthesized using solvent free, fast, easy, green, pyrolysis method, which is characterized using UV–VIS, FTIR, XRD, SEM- EDX and PL technique. Addition of Cr (VI) to fluorescent N–C dot leads to immediate turn OFF in fluorescence with the formation of N–C dot/Cr (VI) nanocomposite. The lowest detection limit of Cr (VI) by N–C dot is 1.42 × 10–9 M. For the first time, we are reporting uric acid, a reducing agent to reduce Cr (VI) to lower valent Cr (III)/Cr (0). The addition of uric acid turns ON the fluorescence with the elimination of inner filter effect (IFE) thus N–C dot/Cr (VI) nanoprobe functioning as a Turn Off–On fluorescent nanosensor for the detection of UA. The efficiency of the sensor is based on fluorescence resonance energy transfer between N-Carbon dots and chromium (VI). A linear response was noted with every nanomolar addition of uric acid. The lowest detection limit toward sensing of UA is found to be 12.5 × 10–9 M. Thus, the novelty of this method is nanomolar amount of redox species is enough to form a stable nanocomposite and the N-CDs/Cr (VI) nanocomposite is able to sense nanomolar to millimolar concentration of uric acid within a few seconds. The nanoprobe is found to be stable, simple and cost effective which can be extended for detection of uric acid in vegetables, fruits and also in clinical studies.

Copper reduction to metallic copper from dilute acid solutions containing Cu+2 was studied by means of sawdust from Radiata Pine as a reducing agent. Influence of the temperature, copper concentrat...

As applied to the radioactive waste vitrification technology, it was established that ruthenium exists in nitric acid solutions in the form of nitrate complexes, which decompose on heating with the release of volatile RuO4 at a nitric acid concentration above 4 M and in the presence of nitrates decomposing on heating to NO2.The release of RuO4 upon heating nitric acid solutions is suppressed by the introduction of reducing agents or by the removal of nitric acid from the reaction zone. Reducing the volatility of ruthenium is also possible by making a cold protective cap on the surface of the molten glass. RuO4 is unstable at temperatures above 100°C and decomposes into non-volatile RuO2, which has the catalytic acceleration effect on decomposition. Decomposition of RuO4 is also accelerated in the presence of metal surfaces. The methods for capturing ruthenium from the gas phase are considered. It is demonstrated that silica gel is not appropriate adsorbent for capturing ruthenium.

The physio-chemical properties of metallic nanoparticles are different from their corresponding bulk material. Synthesizing stable zero valent copper nanoparticles is a challenge since they get oxidized easily. This paper discusses both the batch and continuous synthesis of copper nanoparticles using a polyol process in the absence of an inert atmosphere. The nanoparticles were synthesized using copper amine complex as a precursor, ascorbic acid as a reducing agent, and polyvinyl pyrrolidone as a capping agent. UV-Vis spectra confirmed that particles from a continuous synthesis had better Localized Surface Plasmon Resonance (LSPR) peak than those from batch synthesis. At 120 °C, nanoparticles in the continuous process could be synthesized at a residence time of 1 min in contrast to the batch reactor, which needed a reaction time of 4 min. The nanoparticles synthesized were of size 1.5–6 nm. Those synthesized in continuous mode were stable for 10 days as compared to those synthesized in batch mode.

A simple wet-chemical route for the preparation of core-shell-structured catalysts was developed to achieve high oxygen reduction reaction (ORR) activity with a low Pt loading amount. Nickel nitride (Ni3N) nanoparticles were used as earth-abundant metal-based cores to support thin Pt layers. To realize the site-selective formation of Pt layers on the Ni3N core, hydrogen molecules (H2) were used as a mild reducing agent. As H2 oxidation is catalyzed by the surface of Ni3N, the redox reaction between H2 and Pt(IV) in solution was facilitated on the Ni3N surface, which resulted in the selective deposition of Pt on Ni3N. The controlled Pt formation led to a subnanometer (0.5-1 nm)-thick Pt shell on the Ni3N core. By adopting the core-shell structure, higher ORR activity than the commercial Pt/C was achieved. Electrochemical measurements showed that the thin Pt layer on Ni3N nanoparticle exhibits 5 times higher mass activity and specific activity than that of commercial Pt/C. Furthermore, it is expected that the proposed simple wet-chemical method can be utilized to prepare various transition-metal-based core-shell nanocatalysts for a wide range of energy conversion reactions.

Reductive cleavage of aromatic and benzylic C–O bonds by chromium catalysis is reported. This deoxygenative reaction was promoted by low-cost CrCl2 precatalyst combined with poly(methyl hydrogen siloxane) as the mild reducing agent, providing a strategy in forming reduced motifs by cleavage of unactivated C–O bonds. A range of functional groups such as bromide, chloride, fluoride, hydroxyl, amino, and alkoxycarbonyl can be retained in the reduction.

Reduction chemistry induced by divalent lanthanides has been primarily focused on samarium so far. In light of the rich physical properties of the lanthanides, this limitation to one element is a drawback. Since molecular divalent compounds of almost all lanthanides have been available for some time, we used one known and two new non-classical reducing agents of the early lanthanides to establish a sophisticated reduction chemistry. As a result, six new d/f-polyphosphides or d/f-polyarsenides, [K(18-crown-6)] [Cp''2 Ln(E5 )FeCp*] (Ln=La, Ce, Nd; E=P, As) were obtained. Their reactivity was studied by activation of P4 , resulting in a selective expansion of the P5 rings. The obtained compounds [K(18-crown-6)] [Cp''2 Ln(P7 )FeCp*] (Ln=La, Nd) are the first examples of an activation of P4 by a f-element-polypnictide complex. Additionally, the first systematic femtosecond (fs)-spectroscopy investigations of d/f-polypnictides are presented to showcase the advantages of having access to a broader series of lanthanide compounds.