Materials for solar hydrogen production with simultaneous mineralization of ethanol

The photo-catalytic production of hydrogen by means of irradiation of a suspension of semiconductor oxides presents attractive features over other methods with higher cost such as water electrolysis. In this work, photocatalytic hydrogen production from water is studied, using ethanol as sacrificial agent. New nanostructured multifunctionalised semiconductor materials based on titanium dioxide, with effective photo-catalytic properties under UV illumination were synthesized using sol-gel technology and characterised by X-Ray diffraction and scanning electron microscopy. Aqueous suspensions of the semiconductor powders were used and the effect of solution pH and temperature (20-70ºC) as well as the effect of concentration of ethanol on hydrogen production were studied, for fixed concentrations of the catalyst. Comparison is made with doped Degussa-P25 TiO2 titanium dioxide. The need to decrease the electron-hole recombination rate was accounted for by metal doping [1] with the ethanol molecule acting as a hole trap. An increase in the hydrogen production rate was found as a result of the percentage of metal on doped titania and optimisation of experimental conditions with rate values being superior to recently published literature data [2]. Particle size, reactive surface area, structure and crystallinity of the semiconductor were found to be determinant in the production of highly photoactive titanium dioxide. Research in progress includes development of catalyst that allows effective utilization of visible light and design of an experimental reacto

Rover testing for lunar science and innovation

Instrumentatio

Carbon coatings on optical fibres by PECVD

An RF plasma CVD equipment was built for carbon coating on moving optical fibres. The effects of process parameters and gas composition on coating properties and deposition rate were investigated. Finally best results were obtained with C2H2-Ar plasmas. Homogeneous deposits could be obtained with a typical growth rate of 50 nm/s at fibre drawing speeds up to 2m/s

Design and experimentation of an inductive R.F. plasma process for high speed carbon coating of silica optical fibres

info:eu-repo/semantics/publishe

Carbon coatings on optical fibres by PRCVD

info:eu-repo/semantics/publishe