Tribocatalysis, as a new approach in environmental purification, has drawn increasing attention in the past few years. In this work, we successfully convert mechanical energy to chemical energy by Bi12TiO20, which was synthesized by a hydrothermal method. Under magnetic stirring, electrons transfer from the surface of Bi12TiO20 to the polytetrafluoroethylene-sealed magnetic bar due to their friction. Moreover, the holes that remain on Bi12TiO20 provide oxidation properties in the process for organic matter degradation. According to a series of tests, it is noticed that the shape of the stirring bar and the material of the reaction vessel have a remarkable influence on the removal efficiency of contaminants. Simultaneously, multiple tests reveal the high stability of Bi12TiO20. A great potential for Bi12TiO20 to control water pollutants under dark conditions during collection of ambient mechanical energy was clearly demonstrated in this study.