Tomás Gamasa, MaríaMascareñas Cid, José Luis2020-02-202020-06-112019M. Tomás-Gamasa, J. L. Mascareñas, ChemBioChem 2020, 21, 294http://hdl.handle.net/10347/20791This is the peer reviewed version of the following article: M. Tomás-Gamasa, J. L. Mascareñas, ChemBioChem 2020, 21, 294, which has been published in final form at https://doi.org/10.1002/cbic.201900229. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe conversion of sunlight into chemical energy by using photosynthetic machinery is at the heart of nature and life. Scientists have also learned to use light energy to promote a great variety of chemical reactions, most of which are based on redox processes involving electron‐transfer steps. Indeed, the area of photoredox catalysis has recently emerged as one of the hottest fields in synthetic chemistry. Many of the photoredox reactions discovered so far take place in homogeneous phases, and rely on the use of soluble photoresponsive catalysts. However, in recent years, there have been many advances in the area of heterogeneous photocatalysis, most of which are based on the use of semiconductor materials, such as TiO2, as a key photocatalytic system. These technologies have found different applications, especially in the field of sustainable chemistry and therapy. Herein, some of these applications, and the potential of TiO2‐based photocatalysts in biology and biomedicine, are reviewedeng© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsBioorthogonal chemistryEnergy conversionHeterogeneous catalysisPhotochemistryTitaniumjournal article10.1002/cbic.2019002291439-7633open access