Study on the Improvement of the Degradation Efficiency of Methylene Blue Using Pulsed Direct-Current Self-Power Supply

Effective treatment of dye wastewater is currently a great concern and a research hotspot. Electrocatalysis has unique advantages in treating toxic and harmful refractory dye wastewater; however, it requires an external power supply, which increases energy consumption and cost. As a new energy collection technology, triboelectric nanogenerators (TENGs) have gained considerable attention. In this study, an origami multilayer spherical friction nanogenerator (Q-TENG) was developed for the removal of methylene blue (MB) from dye wastewater. The current and voltage output performances of Q-TENG were explored, and the removal and degradation mechanisms of MB were discussed. Results indicated that when the water wave acceleration a = 3 m/s², the open-circuit voltage and short-circuit current reached the maximum values of 179 V and 9.4 μA, respectively. The self-powered catalytic degradation of MB using Q-TENG can produce more ^•OH and SO₄^-•, and the free radicals increase with increasing action time of Q-TENG, thus increasing the degradation efficiency of MB. This study provides a new strategy for solving the problem of high energy consumption during electrochemical reactions in wastewater treatment.