In the viewpoint of the energy and environment in the future, the present most opinions of our use of the carbon-based fossil fuels is very negative and the evidences of the negative consequences (e.g. the depletion of fossil fuels, the emission of carbon dioxide that is one of the most important cause of global warming) continues to mount. Among various technical strategies to get rid of such situations, artificial photosynthesis using sunlight is one of the most promising technologies for the development of clean energy and the environment remediation. The solar technologies for artificial photosynthesis include photocatalysts and photoelectrochemical cell. Over the past several decades, many efforts have been made to improve the performance efficiency of them. In this talk, we will present our representative photocatalytic-(e.g., two dimensional metal oxides based hybrid materials) and photoelectrode materials (e.g., bismuth vanadate photoanode) and various strategies to improve their performance.