Triboelectric Nanogenerator for Sustainable Wastewater Treatment via a Self-Powered Electrochemical Process

By harvesting the flowing kinetic energy of water using a rotating triboelectric nanogenerator (R-TENG), this study demonstrates a self-powered wastewater treatment system that simultaneously removes rhodamine B (RhB) and copper ions through an advanced electrochemical unit. With the electricity generated by R-TENG, the removal efficiency (RE) of RhB can reach the vicinity of 100% within just 15 min when the initial concentration of RhB is around 100 ppm at optimized conditions. The removal efficiency of copper ions can reach 97.3% after 3 h within an initial concentration of 150 ppm at an optimized condition. Importantly, a better performance and higher treating efficiency are found by using the pulsed output of R-TENG than those using direct current (DC) supply for pollutant removal when consuming equal amount of energy. The recovered copper layer on the cathode through R-TENG is much denser, more uniform, and with smaller grain size (d = 20 nm) than those produced by DC process, which also hints at very promising applications of the R-TENG in electroplating industry. In light of the merits such as easy portability, low cost, and effectiveness, this R-TENG-based self-powered electrochemical system holds great potential in wastewater treatment and electroplating industry.