Synthesis Of Nanomaterials Research Articles

Influence of the alcohol and water grades on surfactant-free colloidal syntheses of gold nanoparticles in alkaline water-alcohol mixtures

AbstractTo make the most of the unique properties of nanomaterials, and to bridge the gap between fundamental and applied research, controlled, green, cheap and energy efficient syntheses of nanoparticles are required. In this respect, room and low temperature surfactant-free colloidal syntheses of nanoparticles obtained in low viscosity and low boiling point solvents, without additives or nature-derived extracts, are promising to develop more active (electro)catalysts. Recently, a room temperature synthesis of surfactant-free gold nanoparticles has been documented (Chem. Mater. 2023, 35, 5, 2173) that requires only water, a base such as NaOH, an alcohol and HAuCl4. Unfortunately, the syntheses of nanomaterials are often sensitive to multiple parameters and it is well acknowledged that reproducibility is a general challenge in the chemical sciences, where the synthesis of nanomaterials is no exception. Here, we investigate the effect of the water conductivity and solvent grade on the surfactant-free low temperature (ca. 30 °C) synthesis of colloidal gold nanoparticles obtained in alkaline mixtures of ethanol and water. The synthesis can be performed with relatively low-grade ethanol but requires high purity water. The importance of water with low conductivity is also stressed for syntheses where ethylene glycol and glycerol are used as source of reducing agents. The results of this study over 100 samples pave the way to greener, more controlled and scalable syntheses of surfactant-free gold nanomaterials.

Hydroxide‐derived Nanostructures: Scalable Synthesis, Characterization, Properties and Potential Applications

AbstractMetal oxide nanostructures have received an increasing attention owing to their unique chemical and physical properties along with their widespread applications in various fields. In this article, we provide an overview of our recent discovery – christened Hydroxides‐Derived Nanostructures, or HDNs – in which we react hydroxide aqueous solutions (mostly tetramethylammonium hydroxide, TMAH) at temperatures < 100 °C and under atmospheric pressure with various metal‐containing precursors to scalably prepare novel metal oxide nanostructures. In one case, we converted a dozen commercial and earth abundant Ti‐containing powders such as binary carbides, nitrides, borides, among others, into new, one‐dimensional TiO2–based lepidocrocite (1DL) nanofilaments (NFs). Application‐wise, 1DLs show outstanding performance in a number of energy, environmental, and biomedical fields such as photo‐ and electrocatalysis, water splitting, lithium‐sulfur and lithium‐ion batteries, water purification, dye degradation, cancer therapy, and polymer composites. In addition to 1DL, the HDNs family encompasses other metal oxides nanostructures including magnetic Fe3O4 nanoparticles and MnO2 birnessite‐based crystalline two‐dimensional (2D) flakes. The latter showed promise as a bifunctional electrocatalyst for water oxidation and oxygen reduction, as well as cathodes in aqueous asymmetric supercapacitor and in an aqueous ammonium ion battery. Our developed recipe provides a new vista in the molecular self‐assembly synthesis of metal oxide nanomaterials that can advance the field with a library of novel nanostructures with substantial implications in a multitude of fields.This article is protected by copyright. All rights reserved

Enzymes-based nanomaterial synthesis: an eco-friendly and green synthesis approach

Enzymes-based nanomaterial synthesis: an eco-friendly and green synthesis approach

Development of a scalable recombinant system for cyclic beta-1,2-glucans production

BackgroundCyclic β-1,2-glucans (CβG) are bacterial cyclic homopolysaccharides with interesting biotechnological applications. These ring-shaped molecules have a hydrophilic surface that confers high solubility and a hydrophobic cavity able to include poorly soluble molecules. Several studies demonstrate that CβG and many derivatives can be applied in drug solubilization and stabilization, enantiomer separation, catalysis, synthesis of nanomaterials and even as immunomodulators, suggesting these molecules have great potential for their industrial and commercial exploitation. Nowadays, there is no method to produce CβG by chemical synthesis and bacteria that synthesize them are slow-growing or even pathogenic, which makes the scaling up of the process difficult and expensive. Therefore, scalable production and purification methods are needed to afford the demand and expand the repertoire of applications of CβG.ResultsWe present the production of CβG in specially designed E. coli strains by means of the deletion of intrinsic polysaccharide biosynthetic genes and the heterologous expression of enzymes involved in CβG synthesis, transport and succinilation. These strains produce different types of CβG: unsubstituted CβG, anionic CβG and CβG of high size. Unsubstituted CβG with a degree of polymerization of 17 to 24 glucoses were produced and secreted to the culture medium by one of the strains. Through high cell density culture (HCDC) of that strain we were able to produce 4,5 g of pure unsubstituted CβG /L in culture medium within 48 h culture.ConclusionsWe have developed a new recombinant bacterial system for the synthesis of cyclic β-1,2-glucans, expanding the use of bacteria as a platform for the production of new polysaccharides with biotechnological applications. This new approach allowed us to produce CβG in E. coli with high yields and the highest volumetric productivity reported to date. We expect this new highly scalable system facilitates CβG availability for further research and the widespread use of these promising molecules across many application fields.

Direct Observation of Covalently Bound Clusters in Resonantly Stabilized Radical Reactions and Implications for Carbonaceous Particle Growth.

Based on quantum mechanically guided experiments that observed elusive intermediates in the domain of inception that lies between large molecules and soot particles, we provide a new mechanism for the formation of carbonaceous particles from gas-phase molecular precursors. We investigated the clustering behavior of resonantly stabilized radicals (RSRs) and their interactions with unsaturated hydrocarbons through a combination of gas-phase reaction experiments and theoretical calculations. Our research directly observed a sequence of covalently bound clusters (CBCs) as key intermediates in the evolution from small RSRs, such as benzyl (C7H7), indenyl (C9H7), 1-methylnaphthyl (1-C11H9), and 2-methylnaphthyl (2-C11H9), to large polycyclic aromatic hydrocarbons (PAHs) consisting of 28 to 55 carbons. We found that hydrogen abstraction and RSR addition drive the formation and growth of CBCs, leading to progressive H-losses, the generation of large PAHs and PAH radicals, and the formation of white smoke (incipient carbonaceous particles). This mechanism of progressive H-losses from CBCs (PHLCBC) elucidates the crucial relationship among RSRs, CBCs, and PAHs, and this study provides an unprecedentedly seamless path of observed assembly from small RSRs to large nanoparticles. Understanding the PHLCBC mechanism over a wide temperature range may enhance the accuracy of multiscale models of soot formation, guide the synthesis of carbonaceous nanomaterials, and deepen our understanding of the origin and evolution of carbon within our galaxy.

Waste Biomass-Derived Activated Carbon-Supported 0D, 1D, 2D, and 3D Nanostructures of Copper Oxide for Hydrogenation Reaction: A Study on the Role of Structural Properties.

Intensive attention is given to the morphology-controlled synthesis of inorganic nanomaterials because of their intrinsic shape-dependent properties. In this article, different dimensions (D) of copper oxide (CuO) nanoparticles (such as 0D-sphere, 1D-rod, 1D-belt, 2D-rolling pin sheets, 3D-octahedron, and 3D-throne) are prepared. The catalytic efficacy of these differently shaped CuO catalysts is compared for hydrogenation reactions under reducing agent-free conditions. The order of catalytic activity of the CuO catalyst is found to be belt > octahedron > rolling pin > rod > sphere > throne. The best catalyst among the different shaped CuO catalysts, namely belt shape, is supported on the functionalized groundnut shells activated carbon sheets (FGNC). Interestingly, 25 wt % CuO/FGNC catalysts exhibit the highest catalytic activity for the reduction of nitro compounds. Importantly, the highly active FGNC-supported catalyst is reused for up to 10 cycles without any noticeable loss in the catalytic activity.

Effects of CaCO3/MgO on Fe-Co-Mo catalyst in the reprocessing of recycled polypropylene to carbon nanotubes

In recent times, there has been a global discourse on the menace of plastic waste (PW) materials on the ecosystem and ways for effective management of PW. This has resulted in the utilization of PW in the research arena in the synthesis of smart nanomaterials of high value as a sustainable solution. In this study, the catalytic-pyrolysis procedure was used to develop carbon nanotubes (CNTs) from recycled polypropylene (PP) plastic in a one-step chemical vapour deposition (CVD) reactor. The impacts of CaCO3 and MgO as supports for Fe-Co-Mo catalysts in the production of CNTs were studied. Kinetic and thermodynamic parameters were determined from the thermal profile of the catalysts to establish the nature of the reaction in CNTs synthesis. Transmission electron microscopy (TEM), energy Dispersive X-ray (EDX), selected area electron diffraction pattern, particle size distribution (PSD), thermogravimetric analysis (TGA), Raman spectroscopy, Fourier transforms infrared (FTIR) and X-ray diffraction (XRD) were employed to characterize the catalysts and CNTs. The results obtained showed the impact of the supports on the yield, quality, and morphology of the synthesized CNTs. The CNTs yield from catalysts supported with CaCO3 and MgO were 35.12 % and 37.24% respectively. The average outer diameters of CNTs produced over the catalyst with CaCO3 and MgO supports were 36 and 29 nm respectively. The ID/IG ratio for CaCO3 and MgO supports were 0.6724 and 0.8401 respectively. The change in entropy for all phases were −274.41 and −1032.97 J/mol/K and −213.0, −318.48 and −1022.13 J/mol/K for CaCO3 and MgO supported catalyst respectively which confirmed non-spontaneous endothermic reaction. It was observed that MgO support showed better catalytic activity toward CNTs growth in terms of yield while those with CaCO3 support showed higher graphitization.

Eco-friendly synthesis of novel magnesium oxide nanomaterials for dye degradation, battery, and sensor applications

Nowadays green synthesis is being incorporated into various technological fields to achieve more sustainable and environmentally friendly processes. By reducing the use of hazardous chemicals, minimizing waste generation, and utilizing renewable resources, green synthesis offers potential solutions to address environmental concerns and promote sustainable development in technology sectors. Herein we demonstrate an environmentally friendly green approach for the fabrication of MgO nanoparticles by using various fruit extracts. In this current study, watermelon, Aloe vera, and Jamun fruit extracts are used as fuel for the synthesis of MgO nanomaterials. Prepared materials were characterized by various characterization techniques. Scanning electron microscopy (SEM) images demonstrate the porous nature of the material and the Diffused reflectance spectroscopy (DRS) reveals the energy gap (4.8–4.9 eV) of the material. Photocatalytic degradation of Direct Green (DG) dye was evaluated under UV light irradiation and the catalyst prepared via jamun fuel (MgO-J) exhibited excellent catalytic activity at 84% for the degradation of DG dye under UV light and better electrochemical behavior as an electrode material compared to other prepared materials. This present work demonstrates a highly efficient eco-friendly route to synthesize MgO nanoparticles for multifunctional applications and also encourages sustainable development in technology areas.

Comparative versatility and diverse biological applications of eco-friendly zinc oxide and cobalt oxide nanoparticles using Punica granatum L. peel extract

A fundamental element of nanotechnology today is the advancement of sustainable, environmentally friendly and economically viable approaches to green synthesis of nanomaterials. In this study, fresh aqueous extract of pomegranate peels was used as reducing and stabilizing agents in a rapid and eco-friendly approach for the synthesis of zinc oxide nanoparticles (ZnO-NPs) and cobalt oxide nanoparticles (Co3O4-NPs). X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission electron microscope (TEM), Energy Dispersive Analysis of X-rays (EDX), and Fourier-transform Infrared Spectroscopy (FT-IR) were used to analyze the biosynthesized ZnO-NPs and Co3O4-NPs. XRD analysis confirmed the crystalline structures of ZnO-NPs and Co3O4-NPs as approximately 33.4 and 11.9nm, respectively. SEM images showed distinct morphologies, while EDX and elemental mapping confirmed compositional integrity. FT-IR validated the characteristic functional groups present in both nanoparticles. TEM analysis provide the average particle size of ZnO-NPs and Co3O4-NPs were observed at 41.25 and 17.19nm, respectively. The zeta potential of green synthesized ZnO-NPs and Co3O4-NPs were found to have a distinct peak at -12.5 and -16.3mV, respectively. Both NPs have shown potent antimicrobial activity against four common pathogens, with increased antimicrobial activity against increasing concentrations of NPs. In vivo studies show a protective role for both ZnO-NPs and Co3O4-NPs against doxorubicin (DOX)-induced toxicity. In addition, Co3O4-NPs were effective against hepatotoxicity, nephrotoxicity, and endocrine disruption in male albino rats. Multi-technique investigation in this study offers a comprehensive understanding and indicates promising biological applications of ZnO-NPs and Co3O4-NPs.

Piperidine and Isobutyl-Nitrite Fuels for the Combustion Synthesis of Nanomaterials: A Study of Crystal Structure, Microstructure, Thermodynamics, and Optical Properties

In this research, the fuels of piperidine (C5H11N) and isobutyl nitrite (C4H9NO2) were used to produce YVO4:Eu3+ nanoparticles. To remove the remaining organic materials and also to improve the crystal structure, these materials were calcined at 800 and 1000 °C, and then the particle size and morphology of the synthesized nanostructures were monitored using a scanning electron microscope (SEM). It was found that the type of consumed fuel and also the calcination temperature result in significant effects on the morphology of the nanostructures as well as the obtained luminescence properties. The use of isobutyl nitrite and piperidine leads to synthesis of homogeneous powders with particle sizes of 38 and 100 nm, respectively. The Rietveld calculations revealed that the growth of the mentioned particles through calcination at 800 °C leads to a reduction of microstrains from 0.00137 to 0.00048 and 0.00126 to 0.00044, respectively. The exciting of these materials by the wavelength of 307 nm causes the creation of a powerful emission spectrum with the highest intensities at the wavelengths of 594 and 624 nm, which originate from the electron transitions of 5D0-7F1 and 5D0-7F2, respectively. Also, the photoluminescence emission of phosphors synthesized by isobutyl nitrite is higher than that of piperidine, which this phenomenon is consistent with X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA) results which proved that the crystallinity of the phosphors synthesized by isobutyl nitrite is higher than that of piperidine.

Synthesis and application of multifunctional magnetic mesoporous nanomaterials with redox reaction and NIR response in tumor treatment

In recent years, the novel minimally invasive combination therapy for tumors has garnered widespread attention due to its controllable therapeutic target, effective combination therapy outcome, and minimal toxic side effects. This study integrated inorganic nanospheres of ferric oxide (Fe3O4) with mesoporous silica nanoparticles (MSN), along with polymeric organic polymers—polyaniline (PANI) and hyaluronic acid (HA)—to create a multifunctional tumor treatment platform (Fe3O4@MSN@PANI@HA), aiming to enhance the efficacy of therapies that have monotherapy limitations. The Fe2+ within the Fe3O4@MSN@PANI@HA nanoparticles can react with the unique hydrogen peroxide present in the tumor microenvironment to generate hydroxyl radicals (·OH), which possess cytotoxic properties that can selectively eradicate tumor cells, thereby facilitating chemodynamic therapy (CDT). Moreover, Fe3O4@MSN@PANI@HA nanoparticles, when loaded with the chemotherapy drug doxorubicin hydrochloride (DOX), yield Fe3O4@MSN@PANI@HA-DOX nanoparticles. It has been demonstrated that these nanoparticles exhibit commendable drug-loading efficiency and controlled drug-release capabilities, contributing to the chemotherapy of tumors. The inclusion of PANI in the Fe3O4@MSN@PANI@HA nanoparticles endows them with an exceptional photothermal conversion capability. Upon exposure to an 808-nm near-infrared laser (NIR), the photothermal conversion efficiency of the composite nanomaterials reaches 42.76 %, thereby enabling photothermal therapy (PTT) through the thermal ablation of tumor cells. The HA component of the composite nanoparticles provides excellent biocompatibility and a sustained drug-release effect. Simultaneously, it could target tumor cells by recognizing specific receptors that are overexpressed on the cell surfaces, directing the transport of the composite nanoparticles to the tumor site, and selectively destroying tumor cells. This paper confirms the potent therapeutic impact of composite nanoparticles on tumors and offers a novel perspective for designing multifunctional composite nanomaterials.

Nanomaterials in biology and medicine: a new perspective on its toxicity and applications.

Nanotechnology offers excellent prospects for application in biology and medicine. It is used for detecting biological molecules, imaging, and as therapeutic agents. Due to nano-size (1-100 nm) and high surface-to-volume ratio, nanomaterials possess highly specific and distinct characteristics in the biological environment. Recently, the use of nanomaterials as sensors, theranostic, and drug delivery agents has become popular. The safety of these materials is being questioned because of their biological toxicity, such as inflammatory responses, cardiotoxicity, cytotoxicity, inhalation problems, etc., which can have a negative impact on the environment. This review paper focuses primarily on the toxicological effects of nanomaterials along with the mechanisms involved in cell interactions and the generation of reactive oxygen species by nanoparticles, which is the fundamental source of nanotoxicity. We also emphasize the greener synthesis of nanomaterials in biomedicine, as it is non-hazardous, feasible, and economical. The review articles shed light on the complexities of nanotoxicology in biosystems and the environment.

Synthesis and Analysis of Euphorbia cognata Boiss-Assisted Organic-Inorganic Complex: Photosynthesis and Stabilization of CoO Nanoparticles.

Synthesis of metal oxide nanomaterials using phytochemicals has now been regarded as mutually exclusive to chemical synthesis techniques. Here, we have extracted, isolated, and characterized the phytochemicals of Euphorbia cognata Boiss leaf hydro-organic extract and utilized them as biofuel in the preparation of metal oxide nanoparticles (CoO NPs). To evaluate the chemical composition of bio templates, chromatographic techniques like high-performance liquid chromatography (HPLC) and gas chromatography-mass spectroscopy (GC-MS) were being utilized. The reducing properties of the organic fuel were investigated by efficiently synthesizing CoO NPs by treating aqueous plant extract with an aqueous complex of Co(NO3)·6H2O. X-ray diffraction (XRD) was utilized for identification of newly prepared NPs, and composition of elements was inveterate via energy dispersive X-ray spectroscopy (EDX). The spherical-shaped morphology was noticed via field emission-scanning electron microscopy (FE-SEM), and the biocomponents of synthesized metal oxide were identified by GC-MS which has confirmed the active presence of monopolized octodrine, decanoic acid, cathinone, and acetic acid in the synthesized metal oxides NPs. Overall, the present study has demonstrated well the significant potential of E. cognata phytocompounds as fuel in the synthesis of nanomaterial.

Chiral Ligand-Concentration Mediating Asymmetric Transformations of Silver Clusters: NIR-II Circularly Polarized Phosphorescence Lighting.

Near infrared (NIR) emitter with circularly polarized phosphorescence (CPP), known as NIR CPP, has emerged as a key part in the research of cutting-edge luminescent materials. However, it remains a challenge to obtain nanoclusters with NIR CPP activity. Here, we propose an asymmetric transformation approach to efficiently synthesize two pairs of chiral silver nanoclusters (R/S-Ag29 and R/S-Ag16) using an achiral Ag10 nanocluster as starting material in the presence of different concentration chiral inducer (R/S)-1,1'-binaphthyl-2,2'-diyl hydrogenphosphate (R/S-BNP). R/S-Ag29, formed in the low-concentration R/S-BNP, exhibits a unique kernel-shell structure consisting of a distorted Ag13 icosahedron and an integrated cage-like organometallic shell with a C3 symmetry, and possesses a superatomic 6-electron configuration (1S2ǀ1P4). By contrast, R/S-Ag16, formed in the high-concentration R/S-BNP, features a sandwich-like pentagram with AgI-pure kernel. Profiting from the hierarchically chiral structures and superatomic kernel-dominated phosphorescence, R/S-Ag29 exhibits infrequent CPP activity in the second near-infrared (975 nm) region, being the first instance of NIR-II CPP observed among CPL metal nanoclusters. This study presents a new approach to reduce the difficulty of de novo synthesis for chiral silver nanomaterials, and facilitates the design of CPP-active superatomic nanoclusters in NIR region.

Chiral Ligand‐Concentration Mediating Asymmetric Transformations of Silver Clusters: NIR‐II Circularly Polarized Phosphorescence Lighting

Near infrared (NIR) emitter with circularly polarized phosphorescence (CPP), known as NIR CPP, has emerged as a key part in the research of cutting‐edge luminescent materials. However, it remains a challenge to obtain nanoclusters with NIR CPP activity. Here, we propose an asymmetric transformation approach to efficiently synthesize two pairs of chiral silver nanoclusters (R/S‐Ag29 and R/S‐Ag16) using an achiral Ag10 nanocluster as starting material in the presence of different concentration chiral inducer (R/S)‐1,1'‐binaphthyl‐2,2'‐diyl hydrogenphosphate (R/S‐BNP). R/S‐Ag29, formed in the low‐concentration R/S‐BNP, exhibits a unique kernel‐shell structure consisting of a distorted Ag13 icosahedron and an integrated cage‐like organometallic shell with a C3 symmetry, and possesses a superatomic 6‐electron configuration (1S2ǀ1P4). By contrast, R/S‐Ag16, formed in the high‐concentration R/S‐BNP, features a sandwich‐like pentagram with AgI‐pure kernel. Profiting from the hierarchically chiral structures and superatomic kernel‐dominated phosphorescence, R/S‐Ag29 exhibits infrequent CPP activity in the second near‐infrared (975 nm) region, being the first instance of NIR‐II CPP observed among CPL metal nanoclusters. This study presents a new approach to reduce the difficulty of de novo synthesis for chiral silver nanomaterials, and facilitates the design of CPP‐active superatomic nanoclusters in NIR region.

Efficient removal of environmental pollutants by green synthesized metal nanoparticles of Clitoria ternatea

Prevention and management of water pollution are becoming a great challenge in the present scenario. Different conventional methods like carbon adsorption, ion exchange, chemical precipitation, evaporation, and biological treatments remove water pollutants. Nowadays, the requirement for effective, non-toxic and safe waste management strategies is very high. Nanomaterials have been explored in various fields due to their unique characteristics. Green synthesis of nanomaterial is becoming more popular due to their safety, non-toxicity, and ease of scale-up technology. Metal nanoparticles can be synthesized using a green synthesis method using biological sources provided by eco-friendly, non-hazardous nanomaterials with superior properties to bulk metals. Hence, this study has designed a green synthesis of magnetic (cobalt oxide) and noble (gold) nanoparticles from the fresh flowers of Clitoria ternatea. The flavonoids and polyphenols in the extract decreased the energy band gap of cobalt oxide and gold nanoparticles; hence, the capping of the natural constituents in Clitoria ternatea helped form stable metal nanoparticles. The cobalt oxide and gold nanoparticles are evaluated for their potential for eliminating organic pollutants from industrial effluent. The novelty of this present work represents the application of cobalt oxide nanoparticles in the removal of organic pollutants and a comparative study of the catalytic behaviour of both metal nanoparticles. The degradation of bromophenol blue, bromocresol green, and 4–nitrophenol in the presence of gold nanoparticles was completed in 120, 45, and 20 min with rate constants of 3.7 × 10−3/min, 6.9 × 10−3/min, and 16.5 × 10−3/min, respectively. Similarly, the photocatalysis of bromophenol blue, bromocresol green, and 4–nitrophenol in the presence of cobalt oxide nanoparticles was achieved in 60, 90, and 40 min with rate constants of 2.3 × 10−3/min, 1.8 × 10−3/min, and 1.7 × 10−3/min, respectively. The coefficient of correlation (R2) values justify that the degradation of organic pollutants follows first-order kinetics. The significance of the study is to develop green nanomaterials that can be used efficiently to remove organic pollutants in wastewater using a cost-effective method with minimal toxicity to aquatic animals. It has proved to be useful in environmental pollution management.

Controlled Synthesis of Unconventional Phase Alloy Nanobranches for Highly Selective Electrocatalytic Nitrite Reduction to Ammonia

The controlled synthesis of metal nanomaterials with unconventional phases is of significant importance to develop high‐performance catalysts for various applications. However, it remains challenging to modulate the atomic arrangements of metal nanomaterials, especially the alloy nanostructures that involve different metals with distinct redox potentials. Here we report the general one‐pot synthesis of IrNi, IrRhNi and IrFeNi alloy nanobranches with unconventional hexagonal close‐packed (hcp) phase. Notably, the as‐synthesized hcp IrNi nanobranches demonstrate excellent catalytic performance towards electrochemical nitrite reduction (NO2RR), with superior NH3 Faradaic efficiency and yield rate of 98.2% and 34.6 mg h‐1 mgcat‐1 (75.5 mg h‐1 mgIr‐1) at 0 and ‐0.1 V (vs reversible hydrogen electrode), respectively. Ex/in‐situ characterizations and theoretical calculations reveal that the Ir‐Ni interactions within hcp IrNi alloy improve electron transfer to benefit both nitrite activation and active hydrogen generation, leading to a stronger reaction trend of NO2RR by greatly reducing energy barriers of rate‐determining step.

Controlled Synthesis of Unconventional Phase Alloy Nanobranches for Highly Selective Electrocatalytic Nitrite Reduction to Ammonia.

The controlled synthesis of metal nanomaterials with unconventional phases is of significant importance to develop high-performance catalysts for various applications. However, it remains challenging to modulate the atomic arrangements of metal nanomaterials, especially the alloy nanostructures that involve different metals with distinct redox potentials. Here we report the general one-pot synthesis of IrNi, IrRhNi and IrFeNi alloy nanobranches with unconventional hexagonal close-packed (hcp) phase. Notably, the as-synthesized hcp IrNi nanobranches demonstrate excellent catalytic performance towards electrochemical nitrite reduction (NO2RR), with superior NH3 Faradaic efficiency and yield rate of 98.2% and 34.6 mg h-1 mgcat-1 (75.5 mg h-1 mgIr-1) at 0 and -0.1 V (vs reversible hydrogen electrode), respectively. Ex/in-situ characterizations and theoretical calculations reveal that the Ir-Ni interactions within hcp IrNi alloy improve electron transfer to benefit both nitrite activation and active hydrogen generation, leading to a stronger reaction trend of NO2RR by greatly reducing energy barriers of rate-determining step.

Green synthesis of silver nanoparticles by waste of Murcott Mandarin peel as a sustainable approach for efficient heavy metal removal from metal industrial wastewater

This study introduces a sustainable and environmentally friendly method for synthesizing silver nanoparticles (Ag-NPs) using waste from Murcott Mandarin peel (Citrus reticulata Blanco × C. sinensis (L.) Obs.). By repurposing agricultural waste as a precursor for nanoparticle synthesis, the research not only reduces waste but also aligns with green chemistry principles. The synthesis process involved extracting bioactive compounds from Murcott Mandarin peel, which acted as both reducing and stabilizing agents during nanoparticle formation. Characterization techniques, including UV–Vis spectroscopy and X-ray diffraction (XRD), confirmed the successful formation of silver nanoparticles. These nanoparticles demonstrated exceptional efficiency in removing heavy metals from metal industrial wastewater, particularly lead ions. Batch experiments revealed significant adsorption capabilities, with lead ions being uptake by silver nanoparticles at a rate of 42.7 mg/g under optimal conditions of pH 5.5 and 60 min of stirring. Additionally, Murcott Mandarin Solid Residue (MM-SR) obtained from the filtration process during Ag-NP synthesis exhibited promising lead ion uptake, reaching 6.6 mg/g under the same optimal conditions. The eco-friendly synthesis route and the efficient heavy metal removal capabilities of silver nanoparticles underscore the potential of utilizing agricultural waste in nanomaterial synthesis for wastewater treatment. This approach not only tackles waste disposal challenges but also generates value-added materials with practical applications in environmental management. Overall, the study emphasizes the importance of exploring innovative and sustainable pathways for nanoparticle synthesis, highlighting the promising role of silver nanoparticles synthesized from Murcott Mandarin peel waste in cost-effective and environmentally benign strategies for heavy metal removal in metal industrial wastewater treatment.

Unlocking the magnetic potential of Fe2O3 nanoparticles by single-step synthesis of cobalt-infused nanomaterials for chromium removal

Unlocking the magnetic potential of Fe2O3 nanoparticles by single-step synthesis of cobalt-infused nanomaterials for chromium removal