The triboelectric nanogenerators based on the mace-like Cu2WS4@ZnO heterojunction for electrocatalytic degradation

It is an innovative issue to degrade the organic pollutants in sea water by using ocean energy. The triboelectric nanogenerator (TENG) provides an ideal way to perform the idea. However, the output power of TENG is still insufficient for electrocatalytic degradation. In the paper, the mace-like core–shell Cu₂WS₄@ZnO heterojunction was prepared by a simple hydrothermal method. After mixed with PVDF and injected into the Ni(OH)₂/Ni foam with nano-needle array, the Cu₂WS₄@ZnO-PVDF/Ni(OH)₂ positive triboelectric layer with interspersed Ni foam electrode was formed. Then it was used to assemble the TENG with the negative triboelectric layer of nylon film on Cu sheet electrode. Obviously, the interspersed electrode and the inner embedded nano-needle array greatly increase the electrode area and decrease the effective dielectric thickness, the Cu₂WS₄@ZnO heterojunction induces obvious space-charge polarization and further increases the dielectric constant. All these innovative measures increase the instantaneous V_OC from 27.4 to 516.2 V, and the instantaneous J_SC from 0.23 to 0.82 mA/m². Then, the generated charges by TENG were successfully applied to degrade the typical dye polymers into harmless small molecules.