The light-driven water splitting reaction to generate molecular hydrogen and oxygen is one of the most promising processes for producing clean fuels. In the approach we are following we attempt to construct a photoelectrochemical (PEC) cell based on molecular components. The two half reactions, water oxidation (anode-side) and proton reduction (cathode-side), both require their own specialized catalysts, linkages, chromophores, and electrode materials. Initially, these components are made and studied separately, first in solution and subsequently as integrated part of the electrode. The most successful components are combined and studied further as part of a device. In this lecture I will focus on the development of catalysts for proton reduction and water oxidation and will zoom in on some of the complication of the implementation of these components in devices. Also, some future perspectives are provided, on how supramolecular strategies could help in solving some of the problems.