Zero gap alkaline electrolysers hold the key to cheap and efficient renewable energy storage via the production and distribution of hydrogen gas. A zero gap design, where porous electrodes are spacially separated only by the gas separator, allows the unique benefits of alkaline electrolysis to be combined with the high efficiencies currently only associated with the more expensive PEM set-up. This review covers the basics of alkaline electrolysis, and provides a detailed description of the advantages of employing a zero gap cell design over the traditional arrangement. A comparison with different types of zero gap cell designs currently seen in research is made, and a description of recent developments is presented. Finally, the current state of research into zero gap alkaline electrolysis is discussed, and pathways for future research identified. Zero gap alkaline electrolysis will allow excess renewable energy to be stored, transported and used on demand in a green and environmentally friendly manner as when the hydrogen is burnt or passed into a fuel cell it produces only water and energy.

In this critical review the biocidal efficacies of a variety of antimicrobial coatings currently in use for catheter surfaces are discussed to formulate the best strategy for decreasing the risk of catheter-associated infections. The development of new coatings containing antimicrobial chemicals and light-activated antimicrobial agents, and their applicability for use in catheters are summarised (132 references).

N-doped TiO₂ has for many years received interest as visible light photocatalytic materials. Here we give our perspective on the subject with special consideration towards the use of visible light photocatalysts in the field of antimicrobial materials with applications in healthcare environments. The subject is reviewed and critiqued from synthetic techniques to characterisation and assessment of functional properties. N-doped TiO₂ has huge potential to form commercially viable antimicrobial surfaces that are easily implemented within the healthcare environment. We aim to shed light on the illusive nature of the mechanism of the different types of N-doping and comment on how these affect the properties of the catalysts themselves. Small concentrations of nitrogen doped under mild conditions lead to interstitial doping, which also promotes the creation of oxygen vacancies. Many believe that it is these oxygen vacancies that actually promote the formation of visible light photocatalysis and hence there is an indirect correlation between the interstitial doping and the photocatalysis. As the concentration of interstitial nitrogen increases the oxygen vacancies increase, however the presence of oxygen vacancies in turn encourages substitutional doping which then fills the oxygen vacancies. This cyclic relationship leads to photocatalysts that are very sensitive to changing nitrogen concentration.

Sulfur-doped titania thin films were prepared by atmospheric pressure chemical vapour deposition (APCVD) for the first time using titanium tetrachloride, ethyl acetate and carbon disulfide. The films were compared to two industrial self-cleaning products: Activ™ and BIOCLEAN™, and shown to be superior in both photocatalysis and photo-induced superhydrophilicity, two preferential properties of effective self-cleaning coatings. X-Ray diffraction showed the films have the anatase TiO₂ structure. XPS and EDX analysis shows changes in S : Ti ratio with preparative conditions indicating that sulfur has indeed been incorporated into the lattice. S-Doped TiO₂ films were found to be effective agents for killing the bacterium Escherichia coli using light sources commonly found in UK hospitals.