Improving catalysts could minimize the use of fossil fuels, thus helping solve the energy crisis while decreasing greenhouse gases. Our group tries to clarify why catalyst modifiers act to promote catalytic activity or selectivity, and how nanoscale features of the catalyst surface can tuned to make better catalysts. In solar cells and LEDs, charge injection and extraction occurs at the interface between a metal or other conductor and one of the semiconducting materials (inorganic materials in most current commercial devices, but hopefully cheaper-to-make polymer films in the future). We also study the energetics and electronic properties of these interfaces.