Photoelectrocatalytic (PEC) processes represent an effective way to exploit renewable energy in response to the sustainable development objectives. The synergy between photo and electrochemical processes inspired several papers and stimulated research toward new systems that could be increasingly adapted to work under visible or solar radiation, and with minimum bias potential. Since the first appearance of articles on PEC processes in the literature, titanium dioxide has been one of the most studied semiconductor materials: nanostructured electrodes have been especially considered such as nanotubes (NT), which are the main subject of the present article. The software VOSviewer is used to a preliminary analysis of metadata, related to the trend of the research on PEC processes; attention is then paid on the trend of NT-TiO₂ electrodes for application in wastewater treatment in the past year.