Solubility and dissolution kinetics of sulfur and sulfides in electrolyte solvents for lithium-sulfur and sodium-sulfur batteries.

In this study, we monitor the dissolution of sulfur and sulfides in electrolyte solvents for lithium-sulfur (Li-S) and sodium-sulfur (Na-S) batteries. The first aim of this research is to assemble a comprehensive set of data on solubilities and dissolution kinetics that may be used in the simulation of battery cycling. The investigation also offers important insights to address key bottlenecks in the development and commercialization of metal-sulfur batteries, including the incomplete dissolution of sulfur in discharge and insoluble low-order sulfides in charge, the probability of shuttling of soluble polysulfides, and the pausing of the redox reactions in precipitated low order sulfides depending on their degree of solid state.

Carbon-cryogel hierarchical composites as effective and scalable filters for removal of trace organic pollutants from water.

Effective technologies are required to remove organic micropollutants from large fluid volumes to overcome present and future challenges in water and effluent treatment. A novel hierarchical composite filter material for rapid and effective removal of polar organic contaminants from water was developed. The composite is fabricated from phenolic resin-derived carbon microbeads with controllable porous structure and specific surface area embedded in a monolithic, flow permeable, poly(vinyl alcohol) cryogel.

Capacitive mixing with electrodes of the same kind for energy production from salinity differences.

The capacitive mixing technique is aimed at producing renewable energy from salinity differences, for example between sea and river water. The technique makes use of two electrodes that modify their potential in opposite directions when the concentration of the solution in which they are immersed is changed, as a consequence of the dynamics of the electric double layer which forms in the ionic solution. Unfortunately, it is difficult to find two electrodes presenting both optimal performances and opposite potential variations.

Modification of the surface of activated carbon electrodes for capacitive mixing energy extraction from salinity differences.

The "capacitive mixing" (CAPMIX) is one of the techniques aimed at the extraction of energy from the salinity difference between sea and rivers. It is based on the rise of the voltage between two electrodes, taking place when the salt concentration of the solution in which they are dipped is changed. We study the rise of the potential of activated carbon electrodes in NaCl solutions, as a function of their charging state.

Phenolic carbon tailored for the removal of polar organic contaminants from water: a solution to the metaldehyde problem?

Current water treatment technologies are inefficient at treating water contaminated with metaldehyde, an 8-member cyclic tetramer of acetaldehyde widely used as a molluscicide in large-scale agriculture and in gardens, and which has been frequently observed to breach European regulatory limits in the UK due to its high solubility and frequent use. Here, we examine the controls on metaldehyde adsorption onto activated phenolic carbon, namely the influence of activation degree, pore size distribution, particle size, point of zero charge and surface functionalisation, by synthesising "tailored" carbons from phenolic resin. Metaldehyde adsorption has been found to be independent of specific surface area (SBET), which is highly unusual for an adsorption process, and is favoured in carbons with (a) high microporosity with narrow pore size distribution, (b) presence of mesopores which allow efficient diffusive transport, and (c) an absence of negatively charged functional groups.