Sulfur-doped graphene quantum dot-based paper sensor for highly sensitive and selective detection of 4-nitrophenol in contaminated water and wastewater.

4-Nitrophenol (4-NP) is a promulgated priority pollutant, which can cause a negative impact on human health. The development of a direct and effective technique for the rapid detection and screening of 4-NP is, therefore, of urgent need. In this study, the blue luminescent sulfur-doped graphene quantum dots (S-GQDs) with a size of 1-5 nm are fabricated using a one-step pyrolysis procedure in the presence of citric acid and 3-mercaptosuccinic acid.

Boron Doped Graphene Quantum Structure and MoS Nanohybrid as Anode Materials for Highly Reversible Lithium Storage.

Herein, the boron-doped graphene quantum structure (BGQS), which contains both the advantages of 0-D graphene quantum dot and 2-D reduced graphene oxide, has been fabricated by top-down hydrothermal method and then mixed with molybdenum sulfide (MoS) to serve as an active electrode material for the enhanced electrochemical performance of lithium ion battery. Results show that 30 wt% of BGQS/MoS nanohybrid delivers the superior electrochemical performance in comparison with other BGQS/MoS and bare components. A highly reversible capacity of 3,055 mAh g at a current density of 50 mA g is achieved for the initial discharge and a high reversible capacity of 1,041 mAh g is obtained at 100 mA g after 50 cycles.

Size Effect of Ordered Mesoporous Carbon Nanospheres for Anodes in Li-Ion Battery.

The present work demonstrates the application of various sizes of ordered mesoporous carbon nanospheres (OMCS) with diameters of 46-130 nm as an active anode material for Li-ion batteries (LIB). The physical and chemical properties of OMCS have been evaluated by performing scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ adsorption-desorption analysis; small-angle scattering system (SAXS) and X-ray diffraction (XRD). The electrochemical analysis of using various sizes of OMCS as anode materials showed high capacity and rate capability with the specific capacity up to 560 mA·h·g at 0.

Characterization of the Escherichia coli ClpY (HslU) substrate recognition site in the ClpYQ (HslUV) protease using the yeast two-hybrid system.

In Escherichia coli, ClpYQ (HslUV) is a two-component ATP-dependent protease in which ClpQ is the peptidase subunit and ClpY is the ATPase and the substrate-binding subunit. The ATP-dependent proteolysis is mediated by substrate recognition in the ClpYQ complex. ClpY has three domains, N, I, and C, and these domains are discrete and exhibit different binding preferences.

Characterization and photocatalytic activity of vanadium-doped titanium dioxide nanocatalysts.

The vanadium (V)-doped mesoporous titanium dioxide (TiO(2)) nanoparticles with V/Ti ratios from 0-2 wt% were prepared using sol-gel method in the presence of triblock polymers, Pluronic F127. SEM images showed that the V-doped TiO(2) nanoparticles were porous structures. The surface areas and pore sizes were in the range 85-107 m(2)/g and 12-14 nm, respectively.