Provide in a single paragraph of 300 words maximum an overview of the work, including background, methodology, main results, and conclusions.  One of the biggest problems of the 21st century is perhaps the need to provide water for the growing world population. Faced with this global problem around water, pollution is a factor of great importance, since the pollutants generated by industrial and domestic activity can be accumulated and transported by both surface and underground waters, deteriorating their quality. Therefore, it is necessary to study the behavior of these pollutants in water and propose treatment techniques that can eliminate them.

Regarding water treatment techniques, it has been shown that heterogeneous photocatalysis with TiO₂ is a clearly effective and environmentally an advantageous alternative for the removal of organic substances in aqueous media. In photocatalysis degradation processes, the analysis of the influence of the surface phenomena on the degradation reactions is of special interest.

In the present work, the preparation of TiO₂ self-ordered nanotubular films was carried out by means of the electrochemical anodization technique using the electrolyte: 50% Vol. Glycerol + 50% Vol. H2O + NH4F [0.27M), to be utilized in a Photocatalytic Reactor (FR) for the photodegradation of Metoprolol in order to evaluate the efficiency of the heterogeneous photocatalytic as an Advanced Oxidation Processes (AOP) through the photodegradation of the emerging pollutant under study and determine the efficiency of the photodegradation through the technique of gas chromatography coupled to mass spectrometry (GC-MS).