The present disclosure relates to oriented photocatalytic semiconductor surfaces which may include photocatalytic capped colloidal nanocrystals (PCCNs) positioned all in the same orientation. The photoactive material may be employed in a plurality of photocatalytic energy conversion applications such as the photocatalytic reduction of carbon dioxide and water splitting, among others. The disclosed oriented PCCNs, within the oriented photoactive material, may also exhibit different shapes and sizes, and higher efficiency in a light harvesting process. Having all the PCCNs oriented at the same angle and dipole moment may allow the light to interact with the dipole at an increased efficiency, to predict the polarity of the light or a more efficient interaction with the nanocrystals substrate, and therefore, increasing the harvesting efficiency by controlling different parts of the light spectrum in the same system.