The image of CO2 is turning quickly because there are increasing attempts to consider it as resources for hydrocarbon based fuels rather a green house gas. Owing to the limited amount of non-renewable readily available energy sources, the paradigm of energy supply is changing from conventional energy sources to inexhaustible renewable sources such as sunlight, wind, tidal energy. But the current scientific interest is concentrated in the efficient recycling of CO2 from a waste combustion product into a solar fuel by photo reduction method that can be used within the current energy infrastructure. Solar energy as direct solar irradiations is excessively available and it is imperious to utilize it for solar fuel products. In other words, solar to chemical conversion by photo-reduction process is an effective route. Moreover, fuels from solar energy are complementary to solar to electrical energy conversion, but there is still intense research is needed before its successful commercialization. Solar fuels produced from CO2 in comparison with H2 are analyzed and it is seen that these solar-hydrocarbons fuels involves easy transportation and storage than H2 fuel. Photoreduction of CO2 is considered as one of the scientific challenges and has been carried out by different photocatalysts. But the nanostructured photocatalyst owing to their unique optical and electrical property are gaining much attention. Several nanostructured semiconductor photocatalyst such as: metal oxides, heterojunctions, porous materials, layered materials, materials with hierarchical structure, and nanobiocatalysts are acknowledged as good candidate for CO2 photo reduction. This technology not only provides an alternative way to produce the sustainable fuels, but also convert the waste CO2 into valuable chemicals, which is important for keeping our environment clean and sustainable. However, there are still several limitations present in the process of CO2 photoreduction and various strategies have been developed to overcome them. Numerous efforts are required to improve the competence of the photo reduction reaction by developing the novel and efficient photocatalyst with considerable activity, high reaction selectivity. In this chapter, we have summarized several scientific attempts that lead to the design of efficient nanocatalysts for CO2 photo reduction along with their mechanistic pathways.