Photon Up-Conversion with Lanthanide-Doped Oxide Particles for Solar H2 Generation

Abstract

Up-conversion (UC) of infrared (IR) photons into visible radiation constitutes a promising strategy to enhance the light harvesting efficiency of photovoltaic and photoelectrochemical devices. In the present study, we integrate Er3+/Yb3+-codoped yttrium oxide (Y 2O3) submicrometric particles with outstanding up-conversion properties into mesoporous titanium oxide (TiO2) structures sensitized with cadmium selenide (CdSe) for solar hydrogen generation. We demonstrate that the incorporation of these up-converting particles (UCP) leads to effective H2 generation with IR photons. Moreover, based on the analysis of the emission lifetimes, we show that the optical interaction between the emitting UCPs and the CdSe absorber occurs via a radiative emission-reabsorption process. The low cost and toxicity and excellent chemical and thermal stability of our UC phosphors allow envisaging them as real candidates for the new generation of long-term photoelectrochemical devices for solar H2 generation. © 2014 American Chemical Society.