Tailoring the work function of graphene via defects, nitrogen-doping and hydrogenation: A first principles study.

The effect of defects, nitrogen doping, and hydrogen saturation on the work function of graphene is investigated via first principle calculations. Whilst Stone-Wales defects have little effect, single and double vacancy defects increase the work function by decreasing charge density in the-electron system. Substitutional nitrogen doping in defect-free graphene significantly decreases the work function, because the nitrogen atoms donate electrons to the-electron system.

Cellulose Nanocrystals Crosslinked with Sulfosuccinic Acid as Sustainable Proton Exchange Membranes for Electrochemical Energy Applications.

Nanocellulose is a sustainable material which holds promise for many energy-related applications. Here, nanocrystalline cellulose is used to prepare proton exchange membranes (PEMs). Normally, this nanomaterial is highly dispersible in water, preventing its use as an ionomer in many electrochemical applications.

Gram-scale synthesis of alkoxide-derived nitrogen-doped carbon foam as a support for Fe-N-C electrocatalysts.

Non-platinum group metal (non-PGM) catalysts for the oxygen reduction reaction (ORR) are set to reduce the cost of polymer electrolyte membrane fuel cells (PEFCs) by replacing platinum at the cathode. We previously developed unique nitrogen-doped carbon foams by template-free pyrolysis of alkoxide powders synthesized using a high temperature and high pressure solvothermal reaction. These were shown to be effective ORR electrocatalysts in alkaline media.

Identification of catalytic sites in cobalt-nitrogen-carbon materials for the oxygen reduction reaction.

Single-atom catalysts with full utilization of metal centers can bridge the gap between molecular and solid-state catalysis. Metal-nitrogen-carbon materials prepared via pyrolysis are promising single-atom catalysts but often also comprise metallic particles. Here, we pyrolytically synthesize a Co-N-C material only comprising atomically dispersed cobalt ions and identify with X-ray absorption spectroscopy, magnetic susceptibility measurements and density functional theory the structure and electronic state of three porphyrinic moieties, CoNC, CoNC and CoNC.

A Nitrogen-Doped Carbon Catalyst for Electrochemical CO Conversion to CO with High Selectivity and Current Density.

We report characterization of a non-precious metal-free catalyst for the electrochemical reduction of CO to CO; namely, a pyrolyzed carbon nitride and multiwall carbon nanotube composite. This catalyst exhibits a high selectivity for production of CO over H (approximately 98 % CO and 2 % H ), as well as high activity in an electrochemical flow cell. The CO partial current density at intermediate cathode potentials (V=-1.

Macroscale Superlubricity of Multilayer Polyethylenimine/Graphene Oxide Coatings in Different Gas Environments.

Friction and wear decrease the efficiency and lifetimes of mechanical devices. Solving this problem will potentially lead to a significant reduction in global energy consumption. We show that multilayer polyethylenimine/graphene oxide thin films, prepared via a highly scalable layer-by-layer (LbL) deposition technique, can be used as solid lubricants.

Tunable Mixed Ionic/Electronic Conductivity and Permittivity of Graphene Oxide Paper for Electrochemical Energy Conversion.

Graphene oxide (GO) is a two-dimensional graphitic carbon material functionalized with oxygen-containing surface functional groups. The material is of interest in energy conversion, sensing, chemical processing, gas barrier, and electronics applications. Multilayer GO paper has recently been applied as a new proton conducting membrane in low temperature fuel cells.

Lattice Strain Mapping of Platinum Nanoparticles on Carbon and SnO2 Supports.

It is extremely important to understand the properties of supported metal nanoparticles at the atomic scale. In particular, visualizing the interaction between nanoparticle and support, as well as the strain distribution within the particle is highly desirable. Lattice strain can affect catalytic activity, and therefore strain engineering via e.

Secondary nanotube growth on aligned carbon nanofibre arrays for superior field emission.

We report substantial improvement of the field emission properties from aligned carbon nanotubes grown on aligned carbon nanofibres by a two-stage plasma enhanced chemical vapour deposition (PECVD) process. The threshold field decreased from 15.0 to 3.