Formation of mixed metal oxides by femtosecond laser irradiation for solar harvesting

We present a novel method for producing mixed metal oxides using femtosecond laser doping of metallic foil in the presence of oxygen and another metallic dopant. We discuss doping titanium dioxide (TiO2) for above bandgap absorptance by irradiating titanium metal with an evaporated thin film of metal. As a wide bandgap, TiO2 most strongly absorbs in the UV range (? < 387 nm). We explore the possibility of creating intermediate states in the band gap by doping with metals, such as chromium, manganese, and nickel. Using femtosecond laser doping, we produce laser-induced periodic surface structures on a variety of transition and mixed metal oxide surfaces. We present compositional data from X-ray photoelectron and Raman spectroscopy and structural data from scanning electron microscopy. Using a three-electrode setup, we present photoelectrochemical results and show enhanced water oxidation under illumination. Our research presents an innovative approach using laser scanning techniques to create new materials for visible-light water splitting.