Photosynthesis harvests solar energy and stores it in chemical forms. It promises a large scale storage solution. Existing efforts to replicate photosynthesis is either inefficient or costly or both, creating a critical challenge. At Boston College, we are working on strategies to address this challenge through rational material designs and precise synthesis controls. Guided by an insight that complex functionalities may be obtained by combining multiple material components through homo- or hetero-junctions, we have produced a number of material combinations aimed at solving fundamental challenges common in inorganic semiconductors such as poor charge collection, mismatch of energy levels, and weak light absorption. Much of our effort is focused on using these materials for solar water splitting. More recently we have started devising highly specific reaction routes for carbon dioxide photofixation, as well as other chemical transformations important to the society. Exciting new progress in a more technologically relevant field of rechargeable batteries is being made by us, as well.