Reduction of CO2 photocatalyzed by Cu-TiO2-based catalysts: a review

The continuous combustion of non-renewable fossil fuels and the depletion of the natural resources from which they come and, consequently, the continuous increase of carbon dioxide (CO2) emissions into the atmosphere are intensifying the search for the conversion of carbon dioxide to fuels and value-added chemicals, with the main objective of reducing emissions and creating renewable and sustainable energy sources. In this sense, there is a lot of interest in the photocatalytic reduction of CO2 with H2O, mainly using solar energy, which is a renewable source with a continuous and easily available light supply. Recent progress in this area has focused on the development of promising photocatalysts, primarily based on TiO2. In this context, this article analyzes: (i) the role of CO2 in the treatment of problems related to energy and global warming, (ii) the fundamental knowledge of the photocatalytic reduction of CO2, (iii) the role of the catalysts of copper-doped TiO2 in the photocatalytic transformation CO2; as well as (iv) emerging and crucial opportunities for future research employing Cu-TiO2 photocatalysts; mentioning the most up-to-date relevant references.