The use of a solar photoelectrochemical reactor for sustainable production of energy

The conversion of solar energy into H2 via water splitting process is one of the most attractive ways to obtain clean and renewable energy. Unfortunately, the fast back reaction of recombination and high band gap needed to activate the photo-catalytic materials, strongly limit the performances in conventional slurry photo-reactors. In this context we present a new photoelectrochemical approach with a double-chamber reactor configuration for H2 production by water photo-electrolysis. The core of the photo-system is a membrane electrode assembly consisting of different layers which hold distinct two areas of the reactor where the generation of O2 and H2 occurs separately. Particular attention is given to the development, on a nano-scale level, of the materials to be used as photoanode and electrocathode: nanostructured TiO2 arrays and carbon nanotubes are used respectively in the form of thin films separated by a proton conductive membrane. Results showed 3.2 mmol h−1 g−1 of H2 evolution that is about one order of magnitude higher with respect to the activity obtained with conventional slurry photoreactors. Moreover, we present the opportunity to recycle CO2 back to liquid fuels by using the same photoelectrochemical approach.