Figure 1.
(a) Schematic of the vertical contact–separation mode triboelectric nanogenerators (TENG) with TiO2−x NPs embedded in polydimethylsiloxane (PDMS) as friction layers; alternating current is generated upon pressing and releasing; (b) X-ray diffraction (XRD) spectra of the TiO2−x nanoparticles (NPs); (c) The energy band diagram, and (d) Scanning electron microscope (SEM) image of PDMS as a function of the TiO2−x NPs embedded weight ratio.