Stable Cuprous Hydroxide Nanostructures by Organic Ligand Functionalization.

Copper compounds have been extensively investigated for diverse applications. However, studies of cuprous hydroxide (CuOH) have been scarce due to structural metastability. Herein, a facile, wet-chemistry procedure is reported for the preparation of stable CuOH nanostructures via deliberate functionalization with select organic ligands, such as acetylene and mercapto derivatives.

Impacts of ruthenium valence state on the electrocatalytic activity of ruthenium ion-complexed graphitic carbon nitride/reduced graphene oxide nanosheets towards hydrogen evolution reaction.

Design and engineering of effective electrode catalysts represents a critical first step for hydrogen production by electrochemical water splitting. Nanocomposites based on ruthenium atomically dispersed within a carbon scaffold have emerged as viable candidates. In the present study, ruthenium metal centers are atomically embedded within graphitic carbon nitride/reduced graphene oxide nanosheets by thermal refluxing.

Ultrafast Preparation of Nonequilibrium FeNi Spinels by Magnetic Induction Heating for Unprecedented Oxygen Evolution Electrocatalysis.

Carbon-supported nanocomposites are attracting particular attention as high-performance, low-cost electrocatalysts for electrochemical water splitting. These are mostly prepared by pyrolysis and hydrothermal procedures that are time-consuming (from hours to days) and typically difficult to produce a nonequilibrium phase. Herein, for the first time ever, we exploit magnetic induction heating-quenching for ultrafast production of carbon-FeNi spinel oxide nanocomposites (within seconds), which exhibit an unprecedentedly high performance towards oxygen evolution reaction (OER), with an ultralow overpotential of only +260 mV to reach the high current density of 100 mA cm.

Photodynamic Activity of Graphene Oxide/Polyaniline/Manganese Oxide Ternary Composites toward Both Gram-Positive and Gram-Negative Bacteria.

Graphene derivatives have been attracting extensive interest as effective antimicrobial agents. In the present study, ternary nanocomposites are prepared based on graphene oxide quantum dots (GOQD), polyaniline (PANI), and manganese oxides. Because of the hydrophilic GOQD and PANI, the resulting GPM nanocomposites are readily dispersible in water and upon photoirradiation at 365 nm exhibit antimicrobial activity toward both Gram-negative () and Gram-positive ().

Oxygen Reduction Reaction Catalyzed by Carbon-Supported Platinum Few-Atom Clusters: Significant Enhancement by Doping of Atomic Cobalt.

Oxygen reduction reaction (ORR) plays an important role in dictating the performance of various electrochemical energy technologies. As platinum nanoparticles have served as the catalysts of choice towards ORR, minimizing the cost of the catalysts by diminishing the platinum nanoparticle size has become a critical route to advancing the technological development. Herein, first-principle calculations show that carbon-supported Pt clusters represent the threshold domain size, and the ORR activity can be significantly improved by doping of adjacent cobalt atoms.

Graphene Oxide Quantum Dot-Based Functional Nanomaterials for Effective Antimicrobial Applications.

Conventional β-lactam antibiotics are resisted by bacteria at an increasing rate, prompting studies into the development of alternate antibiotic agents. In this personal account, we summarize recent progress in the design and engineering of graphene oxide quantum dot-based nanomaterials as potent antimicrobial agents. Specifically, we examine the impacts of chemical reduction on the antimicrobial activity of graphene oxide quantum dots, and enhancement of the bactericidal performance by the formation of nanocomposites with metal oxide nanoparticles, within the context of photodynamic generation of reactive oxygen species.

Antibacterial Activity of Nitrogen-Doped Carbon Dots Enhanced by Atomic Dispersion of Copper.

Antibiotic resistance is an imminent threat to human health, requiring the development of effective alternate antibacterial agents. One such alternative includes nanoparticle (photo)catalysts that are good at producing reactive oxygen species (ROS). Herein, we report the design and preparation of nitrogen-doped carbon dots functionalized with atomically dispersed copper centers by Cu-N coordination (Cu/NCD) that exhibit apparent antibacterial activity toward Gram-negative () under photoirradiation.

Atomic Dispersion and Surface Enrichment of Palladium in Nitrogen-Doped Porous Carbon Cages Lead to High-Performance Electrocatalytic Reduction of Oxygen.

Metal-nitrogen-carbon (MNC) nanocomposites have been hailed as promising and efficient electrocatalysts toward oxygen reduction reaction (ORR), due to the formation of MN coordination moieties. However, MNC hybrids are mostly prepared by pyrolysis of organic precursors along with select metal salts, where part of the MN sites are inevitably buried in the carbon matrix. This limited accessibility compromises the electrocatalytic performance.

Antimicrobial activity of graphene oxide quantum dots: impacts of chemical reduction.

Design and engineering of graphene-based functional nanomaterials for effective antimicrobial applications has been attracting extensive interest. In the present study, graphene oxide quantum dots (GOQDs) were prepared by chemical exfoliation of carbon fibers and exhibited apparent antimicrobial activity. Transmission electron microscopic measurements showed that the lateral length ranged from a few tens to a few hundred nanometers.

Nanocomposites Based on Ruthenium Nanoparticles Supported on Cobalt and Nitrogen-Codoped Graphene Nanosheets as Bifunctional Catalysts for Electrochemical Water Splitting.

Rational design and engineering of high-efficiency electrocatalysts toward overall water splitting is crucial for the development of hydrogen energy technology. Herein, a facile procedure is described for the preparation of effective bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), where ruthenium nanoparticles are supported on graphene nanosheets that are codoped with atomic cobalt and nitrogen by controlled pyrolysis of melamine-functionalized graphene oxide and metal ion precursors. The obtained nanocomposites (CoNG/Ru) exhibit a remarkable electrocatalytic activity toward both HER and OER in alkaline media, with a respective overpotential of only -15 and +350 mV to reach the current density of 10 mA cm, which is much better than the monometallic counterparts and relevant catalysts in the literature.

Platinum Oxide Nanoparticles for Electrochemical Hydrogen Evolution: Influence of Platinum Valence State.

Electrochemical hydrogen generation is a rising prospect for future renewable energy storage and conversion. Platinum remains a leading choice of catalyst, but because of its high cost and low natural abundance, it is critical to optimize its use. In the present study, platinum oxide nanoparticles of approximately 2 nm in diameter are deposited on carbon nitride (C3N4) nanosheets by thermal refluxing of C3N4 and PtCl or PtCl in water.