Investigations of Earth-abundant Metal Oxide Nanomaterials for Solar Fuel Generation

Developing renewable energy technologies to mitigate anthropogenic climate change is one of the biggest challenges facing humanity in the 21st century. Making use of the Sun’s bountiful energy is society’s best hope for achieving cheap, efficient renewable power on a global scale. Solar-assisted conversion of abundant resources such as CO2 and H2O into valuable hydrocarbons is an attractive proposition in this respect. This work investigates the synthesis and characterization of nanoparticulate metal oxides based mainly on abundant iron and copper, and their application as photocatalysts for CO2 reduction and H2 evolution from water. We begin by presenting a general introduction to artificial photosynthesis and a brief literature review of progress in the field. The synthesis, characterization, and hybrid properties of novel Fe2O3/Cu2O hetero-nanocrystals are then described. These nanoparticles represent one of the few examples of colloidal oxide-oxide hetero-structured nanocrystals in the literature. In subsequent work, we explore Cu2O nanocubes as a semiconducting scaffold for the synthesis of multi-component photocatalytic architectures. This work then led us to study the activity of metallic Cu on TiO2 as a model H2 evolution system and examine the effects of alcoholic scavengers on product distribution in water splitting experiments. Finally, we discuss iron-copper delafossite CuFeO2 which was found to be an active catalyst for the light-assisted hydrogenation of CO2 to CO. We conclude by summarizing some of the lessons learned over the course of this work in trying to develop cheap, efficient artificial photosynthesis catalysts, and attempt to provide useful guidelines that may aid future researchers in this pursuit.Ph.D