Ferroelectric BaTiO3@ZnO core-shell heterojunction triboelectric nanogenerators for electrochemical degradation of MO

Abstract

The self-powered electrocatalyst based on the triboelectric nanogenerators (TENG) is an innovative idea, but the low output power density of TENG greatly hinders its vigorous development. Thus the improvement of output performance of TENG and the exploration of effective electrocatalytic degradation methods are still important task for the development of self-powered electrocatalyst. In the paper, the BaTiO3@ZnO (BTO@ZnO) core-shell heterogeneous nanocomposites have been successfully prepared by two steps of water bath and hydrothermal method, showing obvious ferroelectric properties and significantly improved dielectric properties compared with the pure ZnO and BaTiO3 nanostructures. Then, the prepared BTO@ZnO core-shell heterogeneous nanocomposites were embedded into polydimethylsiloxane (PDMS) matrix as triboelectric layer to assemble TENG. The introduction of BTO@ZnO core-shell heterojunctions greatly increases dielectric constant of triboelectric layer through the space charge polarization, and further significantly improve the output performance. Meantime, the mass ratios of BTO@ZnO in the triboelectric layer were further optimized, as the mass ratio of BTO@ZnO is 10 %, both the open circuit voltage (VOC) and short circuit current (JSC) attain the maximum values, even the output power density also attains to the maximum, and 13 LEDs or even more are lit instantaneously under a gentle hand tap. Lastly, the typical pollutant MO were added into NaCl solution, and the BTO@ZnO/PDMS-based TENG were successfully used to power the electrocatalytic degradation of MO. The strong oxidants of the superoxide hydroxyl radicals OH* and hypochlorite ClO− are continuously formed in the NaCl solution including MO to efficiently degrade the MO molecules.