Stephen Matthew Lyth

Nitrogen-doped carbon-based catalysts are increasingly being studied as Pt-free electrodes for oxygen reduction in polymer electrolyte membrane fuel cells. Here, we study the oxygen reduction activity of stoichiometric carbon nitride, which has much higher nitrogen content and is synthesized at lower temperatures, without using ionic or metallic iron. Carbon nitride was studied and characterized via X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, BET specific surface a

To understand hydrogen uptake in porous carbon materials, we developed machine learning models to predict excess uptake at 77 K based on the textural and chemical properties of carbon, using a dataset containing 68 different samples and 1745 data points. Random forest is selected due to its high performance (R2 > 0.9), and analysis is performed using Shapley Additive Explanations (SHAP). It is found that pressure and Brunauer-Emmett-Teller (BET) surface area are the two strongest predictors of e

Electrochemical oxygen reduction via nonprecious, catalysts has potential to reduce the cost and increase acceptance of hydrogen-powered polymer electrolyte membrane fuel cells. However, because these materials are a complex mixture of carbon, nitrogen, and iron, the nature of the active site is still much debated. By using carbon nitride as an ideal, nitrogen-rich, iron-free catalyst we shed light on the role of carbon–nitrogen bonding in electrochemical oxygen reduction. Carbon nitride was syn

Cellulose is derived from biomass and is useful in a wide range of applications across society, most notably in paper and cardboard. Nanocellulose is a relatively newly discovered variant of cellulose with much smaller fibril size, leading to unique properties such as high mechanical strength. Meanwhile, electrochemical energy conversion in fuel cells will be a key technology in the development of the hydrogen economy, but new lower cost proton exchange membrane (PEM) materials are needed. Nanoc

Abstract Electrochemistry is a promising method to recycle CO 2 into useful carbon feedstock and for storing intermittent renewable energy. To date, Au and Ag nanoparticles are the most active catalysts for electrochemical conversion of CO 2 to CO. However, agglomeration reduces the activity and the high cost slows widespread commercialization. Suitable support materials are thus needed to improve catalyst utilization. We explore carbon foam (CF) as a catalyst support. Compared with carbon black

The authors report extremely low electron field emission thresholds of 0.25V∕μm from lithium salt functionalized multiwall carbon nanotubes adhered to carbon fiber fabric. Crucially, these nanostructured field emitters are flexible, air stable, and produced via a low cost dip-processing method using an aqueous nanotube ink, whereupon the nanotubes spontaneously assemble onto a surface oxidized carbon fiber matrix to form dense mats. The very low emission threshold is rationalized in terms of the

The authors report extremely low electron field emission thresholds from acid oxidized multiwall carbon nanotubes deposited on paper substrates by dip coating in an aqueous nanotube ink. Using paper substrates of differing surface roughness, field emission threshold fields ranging from 0.8to11.6V∕μm were observed, varying in an approximate inverse linear log relationship with the surface roughness of the underlying paper substrate. This study shows how field emission from supported nanotube film

A new and simple method of synthesizing fluorinated carbon at the gram scale is presented by reacting a fluorinated alcohol with sodium at elevated temperatures in a sealed Teflon reactor. The resulting carbon nanoparticles are around 100 nm in diameter, and display a hollow shell morphology, with a significant amount of fluorine doped into the carbon. The nanoparticles disperse easily in ethanol, and are thermally stable up to 400 °C and 450 °C under air and nitrogen, respectively. The nanopart