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Ni/Co-free high-energy positive electrode materials are of great importance to ensure the sustainability of Li-ion battery production and its supply chain in addition to minimizing environmental impact. Here, nanostructured LiMnO 2 with both orthorhombic/monoclinic layered domains is synthesized, and its lithium storage properties and mechanism are examined. High-energy mechanical milling is used to convert the metastable and nanosized LiMnO 2 adopting the cation-disordered rocksalt structure to an optimal domain-segregated layered LiMnO 2 . This positive electrode produces an energy density of 820 W h kg -1 , achieved by harnessing a large reversible capacity with relatively small voltage hysteresis on electrochemical cycles. Moreover, voltage decay for cycling, as observed for Li-excess Mn-based electrode materials, is effectively mitigated. Furthermore, by determining the structure-property relationships of different LiMnO 2 polymorphs, LiMnO 2 with similar domain structure and surface area is successfully synthesized with an alternative and simpler method, without the metastable precursor and high-energy mechanical milling. The cyclability of domain-containing LiMnO 2 is also improved with the use of a highly concentrated electrolyte coupled with a lithium phosphate coating due to the suppression of Mn dissolution. These findings maximize the possibility of the development of high-energy, low-cost, and practical rechargeable batteries made from sustainable and abundant Mn sources without Ni/Co., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Dual-ion batteries (DIBs) are attracting attention due to their high operating voltage and promise in stationary energy storage applications. Among various anode materials, elements that alloy and dealloy with lithium are assumed to be prospective in bringing higher capacities and increasing the energy density of DIBs. In this work, antimony in the form of a composite with carbon (Sb-C) is evaluated as an anode material for DIB full cells for the first time. The behaviour of graphite||Sb-C cells is assessed in highly concentrated electrolytes in the absence and presence of an electrolyte additive (1 % vinylene carbonate) and in two cell voltage windows (2-4.5 V and 2-4.8 V). Sb-C full cells possess maximum estimated specific energies of 290 Wh/kg (based on electrode masses) and 154 Wh/kg (based on the combined mass of electrodes and active salt). The work expands the knowledge on the operation of DIBs with non-graphitic anodes., (© 2023 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

Black phosphorene quantum dots (BPQDs) are most commonly derived from high-cost black phosphorus, while previous syntheses from the low-cost red phosphorus (P red ) allotrope are highly oxidised. Herein, we present an intrinsically scalable method to produce high quality BPQDs, by first ball-milling P red to create nanocrystalline P black and subsequent reductive etching using lithium electride solvated in liquid ammonia. The resultant ~25 nm BPQDs are crystalline with low oxygen content, and spontaneously soluble as individualized monolayers in tertiary amide solvents, as directly imaged by liquid-phase transmission electron microscopy. This new method presents a scalable route to producing quantities of high quality BPQDs for academic and industrial applications., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Dual-graphite batteries (DGBs), being an all-graphite-electrode variation of dual-ion batteries (DIBs), have attracted great attention in recent years as a possible low-cost technology for stationary energy storage due to the utilization of inexpensive graphite as a positive electrode (cathode) material. However, DGBs suffer from a low specific energy limited by the capacity of both electrode materials. In this work, a composite of black phosphorus with carbon (BP-C) is introduced as negative electrode (anode) material for DIB full-cells for the first time. The electrochemical behavior of the graphite || BP-C DIB cells is then discussed in the context of DGBs and DIBs using alloying anodes. Mechanistic studies confirm the staging behavior for anion storage in the graphite positive electrode and the formation of lithiated phosphorus alloys in the negative electrode. BP-C containing full-cells demonstrate promising electrochemical performance with specific energies of up to 319 Wh kg -1 (related to masses of both electrode active materials) or 155 Wh kg -1 (related to masses of electrode active materials and active salt), and high Coulombic efficiency. This work provides highly relevant insights for the development of advanced high-energy and safe DIBs incorporating BP-C and other high-capacity alloying materials in their anodes., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Mechanochemistry refers to unusual chemical reactions induced by mechanical energy at room temperatures. It has attracted increased attention because of advantages, such as being a solution-free, energy saving, high-productivity and low-temperature process. However, there is limited understanding of the mechanochemical process because mechanochemistry is often conducted using closed milling devices, which are often regarded as a black box. This feature article shows that mechanochemical reactions can be controlled by varying milling parameters, such as the mechanical force, milling intensity, time and atmosphere. New nanomaterials with doped and functionalized structures can be produced under controlled conditions, which provide a critical insight for understanding mechanochemistry. A fundamental mechanism investigation using force microscopy is discussed.

2D transition metal carbides and nitrides called "MXene" are recent exciting additions to the 2D nanomaterials family. The high electrical conductivity, specific capacitance, and hydrophilic nature of MXenes rival many other 2D nanosheets and have made MXenes excellent candidates for diverse applications including energy storage, electromagnetic shielding, water purification, and photocatalysis. However, MXene nanosheets degrade relatively quickly in the presence of water and oxygen, imposing great processing challenges for various applications. Here, a facile solvent exchange (SE) processing route is introduced to produce nonoxidized and highly delaminated Ti 3 C 2 T x MXene dispersions. A wide range of organic solvents including methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, dimethyl sulfoxide, chloroform, dichloromethane, toluene, and n -hexane is used. Compared to known processing approaches, the SE approach is straightforward, sonication-free, and highly versatile as multiple solvent transfers can be carried out in sequence to yield MXene in a wide range of solvents. Conductive MXene polymer composite fibers are achieved by using MXene processed via the solvent exchange (SE) approach, while the traditional redispersion approach has proven ineffective for fiber processing. This study offers a new processing route for the development of novel MXene-based architectures, devices, and applications., Competing Interests: The authors declare no conflict of interest., (© 2019 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

As an advanced analytical tool, surface-enhanced Raman scattering (SERS) has broad applications in identification of colorants in paints and glazes, hazard detection to ensure food safety, biomedicine and diagnosis, environmental monitoring, detection of explosives and forensic science. In this review, main types of plasmonic substrates, which include solid substrate with metallic nanostructures and chemically synthesized noble metal colloids, and their fabrication methods are reviewed. The design principles for fabrication of ultrasensitive plasmonic substrates for SERS are presented on the basis of published literature. Finally, various applications of SERS substrates are described, indicating the potential of this technique in practical applications. As an ultrasensitive detection method, SERS is at the core of a rapidly expanding research field., (Copyright © 2017 Elsevier B.V. All rights reserved.)

An anode material incorporating a sulfide is reported. SnS 2 nanoparticles anchored onto reduced graphene oxide are produced via a chemical route and demonstrate an impressive capacity of 350 mA h g -1 , exceeding the capacity of graphite. These results open the door for a new class of high capacity anode materials (based on sulfide chemistry) for potassium-ion batteries.

The hybridisation of Co 3 O 4 and Fe 2 O 3 nanoparticles dispersed in a super P carbon matrix is proposed as a favourable approach to improve the electrochemical performance (reversible capacity, cycling stability and rate capability) of the metal oxide electrodes in metal-ion batteries. Hybrid Co 3 O 4 -Fe 2 O 3 /C is prepared by a simple, cheap and easily scalable molten salt method combined with ball-milling and used in sodium-ion and potassium-ion batteries for the first time. The electrode exhibits excellent cycling stability and superior rate capability in sodium-ion cells with a capacity recovery of 440 mA h g -1 (93% retention) after 180 long-term cycles at 50-1000 mA g -1 and back to 50 mA g -1 . In contrast, Co 3 O 4 -Fe 2 O 3 , Co 3 O 4 and Fe 2 O 3 electrodes display unsatisfactory electrochemical performance. The hybrid Co 3 O 4 -Fe 2 O 3 /C is also reactive with potassium and capable of delivering a reversible capacity of 220 mA h g -1 at 50 mA g -1 which is comparable with the most reported anode materials for potassium-ion batteries. The obtained results broaden the range of transition metal oxide-based hybrids as potential anodes for K-ion and Na-ion batteries, and suggest that further studies of these materials with potassium and sodium are worthwhile.

Nanoflower-like architectures represent a unique type of nanomaterials in which thin 2D nanosheets are self-organised into interconnected structures. Lack of restacking between nanosheets and significant internal porosity are the particular advantages of such nanoscale architectures. A general method for the preparation of nanoflowers of a range of oxides (e.g., FeTiO 3 , TiO 2 , Mn 2 O 3 ) through a two-step procedure of ball milling and subsequent hydrothermal treatment is outlined. Importantly, the synthetic method is valid not only for a single oxide, but is extendable to a family of oxide materials. It is established that the formation of the nanoflowers from ball-milled powders follows a dissolution-precipitation mechanism; this is confirmed by inductively coupled plasma time of flight mass spectrometry measurements. Additional information on the X-ray photoelectron spectroscopy characterisation and intermediate stage of growth of the nanostructures is included. Furthermore, two applications of Mn 2 O 3 nanostructures are briefly investigated. Firstly, their properties for energy storage in the electrodes of electrochemical supercapacitors are presented. A capacitive response in the potential window of -0.1-0.9 V versus an Ag/AgCl reference electrode is observed, with an associated increase of the capacitance values over cycling. Secondly, the use of Mn 2 O 3 nanoflowers as model systems for the development of novel nanofabrication techniques (such as nanopatterning with a He + beam) is investigated., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A simple, cost-effective, and easily scalable molten salt method for the preparation of Li 2 GeO 3 as a new type of high-performance anode for lithium-ion batteries is reported. The Li 2 GeO 3 exhibits a unique porous architecture consisting of micrometer-sized clusters (secondary particles) composed of numerous nanoparticles (primary particles) and can be used directly without further carbon coating which is a common exercise for most electrode materials. The new anode displays superior cycling stability with a retained charge capacity of 725 mAh g -1 after 300 cycles at 50 mA g -1 . The electrode also offers excellent rate capability with a capacity recovery of 810 mAh g -1 (94 % retention) after 35 cycles of ascending steps of current in the range of 25-800 mA g -1 and finally back to 25 mA g -1 . This work emphasizes the importance of exploring new electrode materials without carbon coating as carbon-coated materials demonstrate several drawbacks in full devices. Therefore, this study provides a method and a new type of anode with high reversibility and long cycle stability., (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Sodium-ion batteries are in the spotlight as viable alternatives to lithium-ion batteries in stationary storage and power grid applications. Among possible anode materials, Sb is one of the interesting candidates due to a combination of battery-type potential plateaus in the charge-discharge profiles, high capacity (theoretical capacity of 660 mAh g -1 ), and demonstrated good cyclic stability. The influence of Sb particle size (particularly at the nanoscale range) and the composition of Sb-carbon composites on the electrode performance, stability, and charge storage mechanism is systematically evaluated here for the first time. A range of Sb-carbon nanocomposites with varied Sb particle size (between 50 and ∼1 nm) are studied. The control of the particle size is achieved via varying the carbon and Sb weight ratio in the precursors. The shape of charge-discharge profiles, hysteresis, and the difference in cyclic stabilities and rate performance are analyzed. The nanocomposite with the smallest particle size (∼1 nm) and the largest carbon content provides the most stable cyclic behavior and a better rate capability but suffers from an increased hysteresis between charge and discharge curves. In situ synchrotron X-ray diffraction experiments indicate that the storage mechanism in the Sb-carbon nanocomposites containing Sb nanoparticles is different from the electrodes with bulkier, micron-sized Sb particles, and the electrochemical reaction proceeds through a number of crystalline intermediates.

The electrochemical behaviour of a Sn-based anode in a potassium cell is reported for the first time. The material is active at low potentials vs. K/K(+), and encouraging capacities of around 150 mA h g(-1) are recorded. Experimental evidence shows that Sn is capable of alloying/de-alloying with potassium in a reversible manner.

A range of high-capacity Li-ion anode materials (conversion reactions with lithium) suffer from poor cycling stability and limited high-rate performance. These issues can be addressed through hybridization of multiple nanostructured components in an electrode. Using a Co3O4-Fe2O3/C system as an example, we demonstrate that the cycling stability and rate performance are improved in a hybrid electrode. The hybrid Co3O4-Fe2O3/C electrode exhibits long-term cycling stability (300 cycles) at a moderate current rate with a retained capacity of approximately 700 mAh g(-1). The reversible capacity of the Co3O4-Fe2O3/C electrode is still about 400 mAh g(-1) (above the theoretical capacity of graphite) at a high current rate of ca. 3 A g(-1), whereas Co3O4-Fe2O3, Fe2O3/C, and Co3O4/C electrodes (used as controls) are unable to operate as effectively under identical testing conditions. To understand the structure-function relationship in the hybrid electrode and the reasons for the enhanced cycling stability, we employed a combination of ex situ and in situ techniques. Our results indicate that the improvements in the hybrid electrode originate from the combination of sequential electrochemical activity of the transition metal oxides with an enhanced electronic conductivity provided by percolating carbon chains.

We report subnanometer modification enabled by an ultrafine helium ion beam. By adjusting ion dose and the beam profile, structural defects were controllably introduced in a few-layer molybdenum disulfide (MoS2) sample and its stoichiometry was modified by preferential sputtering of sulfur at a few-nanometer scale. Localized tuning of the resistivity of MoS2 was demonstrated and semiconducting, metallic-like, or insulating material was obtained by irradiation with different doses of He(+). Amorphous MoSx with metallic behavior has been demonstrated for the first time. Fabrication of MoS2 nanostructures with 7 nm dimensions and pristine crystal structure was also achieved. The damage at the edges of these nanostructures was typically confined to within 1 nm. Nanoribbons with widths as small as 1 nm were reproducibly fabricated. This nanoscale modification technique is a generalized approach that can be applied to various two-dimensional (2D) materials to produce a new range of 2D metamaterials.

The electrochemical behaviour of Co3O4 with sodium is reported here. Upon cycling in the voltage window of 0.01-3.0 V, Co3O4 undergoes a conversion reaction and exhibits a reversible capacity of 447 mA h g(-1) after 50 cycles. Therefore, nanostructured Co3O4 presents feasible electrochemical sodium storage, offering possibilities to develop new anode materials for sodium-ion batteries.

We report the preparation of a novel nanocomposite architecture of α-LiFeO2-MWCNT based on clusters of α-LiFeO2 nanoparticles incorporated into multiwalled carbon nanotubes (MWCNTs). The composite represents a promising cathode material for lithium-ion batteries. The preparation of the nanocomposite is achieved by combining a molten salt precipitation process and a radio frequency oxygen plasma for the first time. We demonstrate that clusters of α-LiFeO2 nanoparticles incorporated into MWCNTs are capable of delivering a stable and high reversible capacity of 147 mA h g(-1) at 1 C after 100 cycles with the first cycle Coulombic efficiency of ~95%. The rate capability of the composite is significantly improved and its reversible capacity is measured to be 101 mA h g(-1) at a high current rate of 10 C. Both rate capability and cycling stability are not simply a result of introduction of functionalized MWCNTs but most likely originate from the unique composite structure of clusters of α-LiFeO2 nanoparticles integrated into a network of MWCNTs. The excellent electrochemical performance of this new nanocomposite opens up new opportunities in the development of high-performance electrode materials for energy storage application using the radio frequency oxygen plasma technique.

Molecule-coated nanoparticles are hybrid materials which can be engineered with novel properties. The molecular coating of metal nanoparticles can provide chemical functionality, enabling assembly of the nanoparticles that are important for applications, such as biosensing devices. Herein, we report a new self-assembly of core-satellite gold nanoparticles linked by a simple amino acid l-Cysteine for biosensing of Cu(2+). The plasmonic properties of core-satellite nano-assemblies were investigated, a new red shifted absorbance peak from about 600 to 800 nm was found, with specific wavelength depending on ratios with assembly of large and small gold nanoparticles. The spectral features obtained using surface-enhanced Raman spectroscopy (SERS) provided strong evidence for the assembly of the Cu(2+) ions to the L-Cysteine molecules leading to the successful formation of the core-satellite Cu(l-Cysteine) complex on the gold surfaces. In addition, a linear relationship between the concentration of mediating Cu(2+) and absorbance of self-assembled gold nanoparticles (GNPs) at 680 nm was obtained. These results strongly address the potential strategy for applying the functionalized GNPs as novel biosensing tools in trace detections of certain metal ions., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Technological and scientific challenges coupled with environmental considerations have attracted a search for robust, green and energy-efficient synthesis and processing routes for advanced functional nanomaterials. In this article, we demonstrate a high-energy ball milling technique for large-scale synthesis of nitrogen doped carbon nanoparticles, which can be used as an electro-catalyst for oxygen reduction reactions after a structural refinement with controlled thermal annealing. The resulting carbon nanoparticles exhibited competitive catalytic activity (5.2 mA cm(-2) kinetic-limiting current density compared with 7.6 mA cm(-2) on Pt/C reference) and excellent methanol tolerance compared to a commercial Pt/C catalyst. The proposed synthesis route by ball milling and annealing is an effective process for carbon nanoparticle production and efficient nitrogen doping, providing a large-scale production method for the development of highly efficient and practical electrocatalysts.

A novel nanocomposite architecture of a Fe2O3-SnO2-C anode, based on clusters of Fe2O3 and SnO2 nanoparticles dispersed along the conductive chains of Super P Li™ carbon black (Timcal Ltd.), is presented as a breathable structure in this paper for lithium-ion batteries. The synthesis of the nanocomposite is achieved by combining a molten salt precipitation process and a ball milling method for the first time. The crystalline structure, morphology, and electrochemical characterization of the synthesised product are investigated systematically. Electrochemical results demonstrate that the reversible capacity of the composite anode is 1110 mA h g(-1) at a current rate of 158 mA g(-1) with only 31% of initial irreversible capacity in the first cycle. A high reversible capacity of 502 mA h g(-1) (higher than the theoretical capacity of graphite, ~372 mA h g(-1)) can be obtained at a high current rate of 3950 mA g(-1). The electrochemical performance is compared favourably with those of Fe2O3-SnO2 and Fe2O3-SnO2-C composite anodes for lithium-ion batteries reported in the literature. This work reports a promising method for the design and preparation of nanocomposite electrodes for lithium-ion batteries.

We report the fabrication of quantum wells in ZnO nanowires (NWs) by a crystal phase engineering approach. Basal plane stacking faults (BSFs) in the wurtzite structure can be considered as a minimal segment of zinc blende. Due to the existing band offsets at the wurtzite (WZ)/zinc blende (ZB) material interface, incorporation of a high density of BSFs into ZnO NWs results in type II band alignment. Thus, the BSF structure acts as a quantum well for electrons and a potential barrier for holes in the valence band. We have studied the photoluminescence properties of ZnO NWs containing high concentrations of BSFs in comparison to high-quality ZnO NWs of pure wurtzite structure. It is revealed that BSFs form quantum wells in WZ ZnO nanowires, providing an additional luminescence peak at 3.329 eV at 4 K. The luminescence mechanism is explained as an indirect exciton transition due to the recombination of electrons in the QW conduction band with holes localized near the BSF. The binding energy of electrons is found to be around 100 meV, while the excitons are localized with the binding energy of holes of ∼5 meV, due to the coupling of BSFs, which form QW-like structures.

The mineral ilmenite is one of the most abundant ores in the Earth's crust and it is the main source for the industrial production of bulk titanium oxide. At the same time, methods to convert ilmenite into nanostructures of TiO(2) (which are required for new advanced applications, such as solar cells, batteries, and photocatalysts) have not been explored to any significant extent. Herein, we describe a simple and effective method for the preparation of rutile TiO(2) nanorods from ball-milled ilmenite. These nanorods have small dimensions (width: 5-20 nm, length: 50-100 nm, thickness: 2-5 nm) and possess large specific surface areas (up to 97 m(2)  g(-1)). Dissolution/hydrolysis/precipitation is proposed as a growth mechanism. The nanorods were found to have attractive photocatalytic properties in the degradation of oxalic acid. Their photocatalytic activity is close to that of the benchmark Degussa P25 material and better than that of a commercial high-surface-area rutile powder., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

SnO2 nanoribbons have been synthesized by annealing of a milled SnO2 powder, which is able to evaporate efficiently at the temperature as low as 1100 degrees C due to the metastable structure created by ball milling treatment. When the milled powder was annealed in an assembly of two combustion boats, SnO2 nanoribbons formed on the surface of the milled powder. The nanoribbons tend to grow along the [101] crystallographic direction and their side surfaces are represented by +/- (010) and +/- (101) facets. The oxygen plays an important role in enhancing their formation.

Ball-milling and annealing is one effective method for the mass production of boron nitride nanotubes (BNNTs). We report that the method has been modified to a boron (B) ink annealing method. In this new process, the nanosize ball-milled B particles are mixed with metal nitrate in ethanol to form an ink-like solution, and then the ink is annealed in nitrogen-containing gas to form nanotubes. The new method greatly enhances the yield of BNNTs, giving a higher density of nanotubes. These improvements are caused by the addition of metal nitrate and ethanol, both of which can strongly boost the nitriding reaction, as revealed by thermogravimetric analysis. The size and structure of BNNTs can be controlled by varying the annealing conditions. This high-yield production of BNNTs in large quantities enables the large-scale application of BNNTs.