Design, Characterization and Evaluation of a Lab-made Photoreactor: A First Step Towards Standardized Procedures in Photocatalysis**

For the last fifteen years, photochemistry has known a renewal with the emergence of new photoredox approaches, along with the development of new powerful artificial sources of light. However, the described procedures often lack information about the characteristics of the setups (wavelength, actual received light power, distance from the source) even when commercial apparatuses are used. This lacunar information hampers the development of standardized procedures which would guarantee the reproducibility of the reactions. With the objective of furnishing a standardized setup, a lab-made reactor was designed. The use of 3D-printing technology makes it easily accessible to most laboratories. Its characterization showed the critical effect of the environmental conditions upon the light power received and how crucial they are for reproducibility of photochemical reactions. At last, the setup was evaluated against experiments taken from recent literature.