The role of the surface acidic/basic centers and redox sites on TiO2 in the photocatalytic CO2 reduction

The development of sustainable processes for CO2 reduction to fuels and chemicals is one the most important challenges provide clean energy solutions. use sunlight as renewable source an interesting alternative power electron transfer required artificial photosynthesis. Even if redox sites are mainly responsible this process, other reactive acidic/basic centers also contribute overall reaction pathway. However, a full understanding photoreduction mechanism still scientific challenge. In fact, lack agreement on standardized comparison criteria leads wide distribution reported productions, even using same catalyst, which hinders reliable interpretation. An additional difficulty ascertaining origin carbon-containing products effect surface carbon residues, well intermediates under real dynamic conditions. To determine elusive mechanism, we report interconnected strategy combining in-situ spectroscopies, theoretical studies catalytic experiments. These show that productions influenced by presence deposits (i.e. organic molecules, carbonates bicarbonates) over TiO2 surface. Most importantly, acid/base character medium play key role in selectivity deactivation pathways. This initiated formation peroxo- species, while activity can be partially recovered mild acid washing treatment. We anticipate these findings methodology enlighten main shadows covering and, essential clues design emergent materials reactions photo(electro)catalytic conversion.