Sustainable organic synthesis promoted on titanium dioxide using coordinated water and renewable energies/resources

There is an increasing demand to replace conventional industrial systems that emit massive amounts of CO2 with lower-carbon emitting systems, and this has spurred research on the application of renewable energy for chemical conversions. Hydrogen and other simple chemical products have been efficiently manufactured using renewable light energy or secondary energy sources, such as electricity. More impor-tantly, the direct use of water as a ubiquitous and clean hydrogen (or electron) and oxygen source in organic synthesis has recently been realized. Semiconductor photo-and electrocatalysts, such as metal oxides, play significant roles in energy transformations and in the activation of reactant chemicals. This paper reviews recent developments in organic synthesis using water and renewable light or electric energy to achieve sustainable chemical production. TiO2 is especially featured as a reaction platform where both reactants and water are efficiently activated through coordination with the TiO2 surface. We also discuss the role of water in the reaction on the TiO2 surface from the perspectives of synthetic chemistry, physical surface chemistry, and nanomaterial chemistry.(c) 2022 Elsevier B.V. All rights reserved.