Hexagonal Boron Nitride Quantum Dots Embedded on Layer-by-Layer Films for Peroxidase-Assisted Colorimetric Detection of β-Galactosidase Producing Pathogens.

Pathogen detection has become a major research area all over the world for water quality surveillance and microbial risk assessment. Therefore, designing simple and sensitive detection kits plays a key role in envisaging and evaluating the risk of disease outbreaks and providing quality healthcare settings. Herein, we have designed a facile and low-cost colorimetric sensing strategy for the selective and sensitive determination of β-galactosidase producing pathogens.

Atomically Dispersed Manganese on Graphene Nanosheets as Biocompatible Nanozyme for Glutathione Detection in Liver Tissue Lysate Using Microfluidic Paper-based Analytical Devices.

Recently, single atom catalysts (SACs) featuring M-N (M = metal) active sites on carbon support have drawn considerable attention due to their promising enzyme-like catalytic properties. However, typical synthesis methods of SACs often involve energy-intensive carbonization processes. Herein, we report a facile one-pot, low-temperature, wet impregnation method to fully utilize M-N sites of manganese phthalocyanine (MnPc) by decorating molecular MnPc over the sheets of graphene nanoplatelets (GNP).

Carbon Encapsulated NiCo S Nanoparticles with Enhanced Surface Mediated Charge Storage for Superior Ultracapacitor Electrodes.

Three different compositions of NiCo S (NCS) materials were prepared using three solvents, named NCS HTDI (hydrothermal in DI water), NCS STEG (solvothermal in ethylene glycol), and a novel carbon-encapsulated NCS STFA (solvothermal in formamide). The structural and morphological properties of the prepared NCS HTDI, NCS STEG, and NCS HTDI materials were analyzed using various physical characterization techniques. As prepared, NCS materials were tested as an electrode for supercapacitor (SC) application using a 3-electrode system in a basic electrolyte (3 M KOH).

Few-layer Graphene Lithiophilic and Sodiophilic Diffusion Layer on Porous Stainless Steel as Lithium and Sodium Metal Anodes.

In order to subdue the obvious problem of uneven electric field distribution on regularly used copper/aluminum current collectors for alkali metal batteries, graphene on porous stainless steel (pSS_Gr) was fabricated using the ion etching technique that is employed as an effective host for lithium and sodium metal anodes. The binder-free pSS_Gr demonstrated stable Li plating and stripping at areal current and capacity of 6 mA cm and 2.54 mAh cm , respectively, for over 1000 cycles with 98% coulombic efficiency (C.

The role of 2D material families in energy harvesting: An editorial overview.

The ever increasing proportion of an energy consuming society and the boost in industrialization accelerated the depletion of fossil fuel based energy sources at an alarming rate. This emphasizes the necessity of sustainable energy generation and storage to meet the daily energy demands. But, these alternative renewable energy sources like solar and wind power are intermittent and highly depend on weather, place and individuals.

Research Progress and Perspective on Lithium/Sodium Metal Anodes for Next-Generation Rechargeable Batteries.

With the development of consumer electronic devices and electric vehicles, lithium-ion batteries (LIBs) are vital components for high energy storage with great impact on our modern life. However, LIBs still cannot meet all the essential demands of rapidly growing new industries. In pursuance of higher energy requirement, metal batteries (MBs) are the next-generation high-energy-density devices.

Resistive Switching in HfO/LaSrMnO Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface.

High-performance nonvolatile resistive random access memories (ReRAMs) and their small stimuli control are of immense interest for high-speed computation and big-data processing in the emerging Internet of Things (IoT) arena. Here, we examine the resistive switching (RS) behavior in growth-controlled HfO/LaSrMnO (LSMO) heterostructures and their tunability in a low magnetic field. It is demonstrated that oxygen-deficient HfO films show bipolar switching with a high on/off ratio, stable retention, as well as good endurance owing to the orthorhombic-rich phase constitution and charge (de)trapping-enabled Schottky-type conduction.

Uncovering the origin of enhanced field emission properties of rGO-MnO heterostructures: a synergistic experimental and computational investigation.

The unique structural merits of heterostructured nanomaterials including the electronic interaction, interfacial bonding and synergistic effects make them attractive for fabricating highly efficient optoelectronic devices. Herein, we report the synthesis of MnO nanorods and a rGO/MnO nano-heterostructure using low-cost hydrothermal and modified Hummers' methods, respectively. Detailed characterization and confirmation of the structural and morphological properties are done X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM).

Experimental and theoretical investigations of the effect of heteroatom-doped carbon microsphere supports on the stability and storage capacity of nano-CoO conversion anodes for application in lithium-ion batteries.

Conversion-type anode materials have been intensely studied for application in Li-ion batteries (LIBs) due to their potentially higher capacities than current graphite-based anodes. This work reports the development of a high-capacity and stable anode from a nanocomposite of N and S co-doped carbon spheres (NSCSs) with CoO (NSCS-CoO). A hydrothermal reaction of saccharose with l-cysteine was carried out, followed by its carbonization.

Correction: Synthesis of high surface area porous carbon from anaerobic digestate and it's electrochemical study as an electrode material for ultracapacitors.

[This corrects the article DOI: 10.1039/C9RA06603A.].

Synthesis of high surface area porous carbon from anaerobic digestate and it's electrochemical study as an electrode material for ultracapacitors.

The remnants of the anaerobic digestion process, 'the digestate,' mainly consist of fibrous lignin and cellulose like molecules, as a significant carbon repository along with some other inorganic impurities. The present work demonstrates the potential use of anaerobically treated fruit and vegetable waste (FVW) as a source of porous carbon for supercapacitor electrode materials. This work suggests that the FVW digestate can inherit silicon (Si) and calcium (Ca) based inorganic impurities, which play an essential role as structure directing agents for digestate derived carbon.

High-Energy Flexible Supercapacitor-Synergistic Effects of Polyhydroquinone and RuO· xHO with Microsized, Few-Layered, Self-Supportive Exfoliated-Graphite Sheets.

An effective and straightforward route for tailoring the self-supporting, exfoliated flexible graphite substrate (E-FGS) using electrochemical anodization is proposed. E-FGS has essential features of highly exfoliated, few-layered, two-dimensional graphite sheets with the size of several tens of micrometers, interconnected along the axis of the substrate surface. The novel hierarchical porous structural morphology of E-FGS enables large active sites for efficient electrolyte ion and charge transport when used as electrode material for a supercapacitor.

Biomass-Mediated Synthesis of Cu-Doped TiO Nanoparticles for Improved-Performance Lithium-Ion Batteries.

Pure TiO and Cu-doped TiO nanoparticles are synthesized by the biomediated green approach using the Bengal gram bean extract. The extract containing biomolecules acts as capping agent, which helps to control the size of nanoparticles and inhibit the agglomeration of particles. Copper is doped in TiO to enhance the electronic conductivity of TiO and its electrochemical performance.

Nutty Carbon: Morphology Replicating Hard Carbon from Walnut Shell for Na Ion Battery Anode.

Efficient Na ion intercalation/deintercalation in the semigraphitic lattice of a hard carbon derived from the walnut shell is demonstrated. High-temperature (1000 °C) pyrolysis of walnut shells under an inert atmosphere yields a hard carbon with a low surface area (59 m g) and a large interplanar axis separation of 0.39-0.

Facile Synthesis of Unique Cellulose Triacetate Based Flexible and High Performance Gel Polymer Electrolyte for Lithium Ion Batteries.

Lithium ion batteries (LIBs) with polymer based electrolytes have attracted enormous attention due to the possibility of fabricating intrinsically safer and flexible devices. However, economical and eco-friendly sustainable technology is an oncoming challenge to fulfill the ever increasing demand. To circumvent this issue, we have developed a gel polymer electrolyte (GPE) based on renewable polymers like cellulose triacetate and poly(polyethylene glycol methacrylate) p(PEGMA) using a photo polymerization technique.

Ammonia-modified graphene sheets decorated with magnetic FeO nanoparticles for the photocatalytic and photo-Fenton degradation of phenolic compounds under sunlight irradiation.

Synthesis of easily separable and eco-friendly efficient catalyst with both photocatalytic and photo-Fenton degradation properties is of great importance for environment remediation application. Herein, ammonia-modified graphene (AG) sheets decorated with FeO nanoparticles (AG/FeO) as a magnetically recoverable photocatalyst by a simple in situ solution chemistry approach. First, we have functionalized graphene oxide (GO) sheets by amide functional group and then FeO nanoparticles (NPs) are doped onto the functionalized GO surface.

Facile Green Synthesis of BCN Nanosheets as High-Performance Electrode Material for Electrochemical Energy Storage.

Two-dimensional hexagonal boron carbon nitride (BCN) nanosheets (NSs) were synthesized by new approach in which a mixture of glucose and an adduct of boric acid (H3 BO3 ) and urea (NH2 CONH2 ) is heated at 900 °C. The method is green, scalable and gives a high yield of BCN NSs with average size of about 1 μm and thickness of about 13 nm. Structural characterization of the as-synthesized material was carried out by several techniques, and its energy-storage properties were evaluated electrochemically.

3D Polyaniline Architecture by Concurrent Inorganic and Organic Acid Doping for Superior and Robust High Rate Supercapacitor Performance.

A good high rate supercapacitor performance requires a fine control of morphological (surface area and pore size distribution) and electrical properties of the electrode materials. Polyaniline (PANI) is an interesting material in supercapacitor context because it stores energy Faradaically. However in conventional inorganic (e.

Glucose-Derived Porous Carbon-Coated Silicon Nanowires as Efficient Electrodes for Aqueous Micro-Supercapacitors.

In this study, we report on carbon coating of vertically aligned silicon nanowire (SiNWs) arrays via a simple hydrothermal process using glucose as carbon precursor. Using this process, a thin carbon layer is uniformly deposited on the SiNWs. Under optimized conditions, the coated SiNWs electrode showed better electrochemical energy storage capacity as well as exceptional stability in aqueous system as compared to uncoated SiNWs.

Synthesis of N, F and S co-doped graphene quantum dots.

Graphene quantum dots (GQDs) are a promising category of materials with remarkable size dependent properties like tunable bandgap and photoluminescence along with the possibility of effective chemical functionalization. Doping of GQDs with heteroatoms is an interesting way of regulating their properties. Herein, we report a facile and scalable one-step synthesis of luminescent GQDs, substitutionally co-doped with N, F and S, of ∼2 nm average size by a microwave treatment of multi-walled carbon nanotubes in a customized ionic liquid medium.

Enhanced photoluminescence and photoactivity of plasmon sensitized nSiNWs/TiO₂ heterostructures.

A light sensitive wide band gap radial heterojunction between TiO2 and nSiNWs sensitized by gold nanoparticles is reported. The surface plasmon of AuNPs influences the optical and photocurrent properties of the heterojunction considerably. Improvement in the band gap emission of TiO2 has been found at the expense of defect radiation.

Electrochemical preparation of vertically aligned, hollow CdSe nanotubes and their p-n junction hybrids with electrodeposited Cu2O.

Vertically aligned, hollow nanotubes of CdSe are grown on fluorine doped tin oxide (FTO) coated glass substrates by ZnO nanowire template-assisted electrodeposition technique, followed by selective removal of the ZnO core using NH4OH. A detailed mechanism of nucleation and anisotropic growth kinetics of nanotubes have been studied by a combination of characterization tools such as chronoamperometry, SEM and TEM. Interestingly, "as grown" CdSe nanotubes (CdSe NTs) on FTO coated glass plates behave as n-type semiconductors exhibiting an excellent photo-response (with a generated photocurrent density value of ∼ 470 μA cm(-2)) while in contact with p-type Cu2O (p-type semiconductor, grown separately on FTO plates) because of the formation of a n-p heterojunction (type II).

C@SiNW/TiO2 core-shell nanoarrays with sandwiched carbon passivation layer as high efficiency photoelectrode for water splitting.

One-dimensional heterostructure nanoarrays are efficiently promising as high performance electrodes for photo electrochemical (PEC) water splitting applications, wherein it is highly desirable for the electrode to have a broad light absorption, efficient charge separation and redox properties as well as defect free surface with high area suitable for fast interfacial charge transfer. We present highly active and unique photoelectrode for solar H2 production, consisting of silicon nanowires (SiNWs)/TiO2 core-shell structures. SiNWs are passivated to reduce defect sites and protected against oxidation in air or water by forming very thin carbon layer sandwiched between SiNW and TiO2 surfaces.

Plasmon-enhanced photocurrent generation from click-chemically modified graphene.

The visible-light response of Au nanoparticles (AuNPs) assembled on rGO through different molecular bridges was investigated by transient photocurrent generation. We prepared rGO with two self-assembled monolayers (SAMs), one linear and the other with aromatic triazoles through a click cycloaddition reaction. A fivefold photocurrent enhancement was observed for triazole linkers over the aminopropyltrimethoxysilane (APTMS) linker.

The synthesis of citrate-modified silver nanoparticles in an aqueous suspension of graphene oxide nanosheets and their antibacterial activity.

A composite material consisting of silver nanoparticles (Ag NPs) deposited on graphene oxide (GO) nanosheets is prepared by chemical reduction of Ag metal ions by sodium borohydride (NaBH4) in the presence of trisodium citrate acting as a stabilizing agent to prevent agglomeration of the nanoparticles. The synthesized GO/Ag NPs composite was characterized by UV/vis spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM analysis confirmed a high density of Ag NPs on the GO nanosheets with a particle size range of 2-25 nm.