H2 production by water photo-electrolysis by using a novel TiO2 nanotube array-based photo-reactor

In this work we report on the use of a modular photoelectrochemical (PEe) device for the solar production of H2 by water photo-electrolysis. The aim of the study was to obtain the maximum benefit from the solar irradiation, simulated by a Xe-arc lamp, through i) the development of novel nano-engineered photoactive materials, such as Ti02 nanotube arrays prepared by anodic oxidation of Ti foils and ii) the correct design of the photo-reactor, which must have the best configuration to maximize the efficiency of the process. The presence of two distinct reaction chambers in our PEC system, allowed to form O2 and H2 as two separate gaseous streams, so limiting charge recombination phenomena and avoiding the fast back-reaction to water. Results in terms ofH2 production and generated photo-current showed Pt-doped Ti02 nanotubes to be the best photocatalysts used, where their performances depended upon the operating conditions of the process (liquid or gaseous phase) and also on the parameters chosen during the synthesis of the samples (voltage, time of anodization and nature of the electrolyte).