Direct conversion of CO₂ to a low alcohol using H₂O as electron source is an important long term goal for sunlight to fuel conversion. To take advantage of the flexibility by which energy flow, charge transport and catalytic transformations can be controlled by discreet molecular structures, we are exploring an inorganic ‘molecular’ approach for assembling artificial photosynthetic systems on nanoporous silica supports. Photocatalytic units consist of an oxo-bridged binuclear metal-to-metal charge-transfer group (MMCT), which is coupled to a multi-electron transfer catalyst. In some cases, the binuclear unit itself can act as redox site. We have developed mild synthetic methods for assembling and anchoring oxo-bridged binuclear MMCT units on silica nanopores with high selectivity, based on acidity differences between metal-OH groups and surface silanols (e.g. assembly of TiOCo(II), TiOMn(II)), or selective redox reactivity (TiOCr(III)). Structures of these all-inorganic units were determined by EXAFS, XANES, FT-Raman, FT-IR, EPR and optical spectroscopy. The MMCT groups serve as visible light electron pumps with adjustable potential that depends on the selected donor/acceptor metal and oxidation state. When coupling the TiOCr(III) unit to an Ir oxide nanocluster inside the silica nanopore of MCM-41 silica material, water oxidation was observed upon irradiation of an aqueous suspension with visible light. CO2 splitting to CO was achieved by exciting the MMCT transition of ZrOCu(I) units of ZrCu(I)-MCM-41 loaded with gaseous CO₂. The flexible assembly method of these photocatalytic units opens up opportunities for the efficient coupling of water oxidation with CO₂ reduction sites in robust nanoporous oxide scaffolds.