Bottom-up strategies for the fabrication of nanomaterials have the advantage of scalability, cost-effective and sustainability, and thus hold great potential to solve the current critical energy and environmental issues facing humanity. Current challenges consist of assembly of the nanomaterials into, for example, various forms of films, which are immensely useful in realistic applications of the nanomaterials. The key is to understand the interplay between the material components. In this contribution, I will present some of our recent results in interfacing and assembling different nanostructures at different length scales by solution processes. The resulting architectures have been explored for the efficient conversion of sunlight to chemical fuels. It has proved promising to use earth-abundant materials and low-cost processes to fabricate solar fuel devices for artificial photosynthesis.