Silver nanoparticle-decorated ZnO nanorods for flexible and wearable high-output piezoelectric nanogenerators

Piezoelectric nanogenerators based on the piezoelectric effect have attracted widespread attention. With the advancement of wearable piezoelectric nanogenerators, particularly the continuous expansion of their application scenarios, greater demands are being placed on the flexibility and piezoelectric output of nanogenerator devices. Herein, to address this issue, silver-decorated zinc oxide nanorods were prepared and incorporated into P(VDF-TrFE) to fabricate a flexible composite material with excellent piezoelectric performance. Zinc oxide nanorods were first grown via a hydrothermal method, followed by the successful decoration with silver nanoparticles through visible-light-induced self-assembly. Upon constructing an Ag/ZnO heterojunction, the polarization charges within the zinc oxide (ZnO) nanorods undergo directional migration toward the Ag nanoparticles under mechanical strain. This charge transfer behavior significantly amplifies the macroscopic piezoelectric output of the Ag/ZnO nanorod-embedded P(VDF-TrFE) composite, leading to a marked enhancement in its overall piezoelectric performance. Optimally, at a doping concentration of 7.5 wt%, the composite achieves an output voltage of approximately 17.5 V and a current of about 0.4 μA, which are approximately 2.3 times and 1.2 times those of pure P(VDF-TrFE) film, respectively. This outstanding output enables the PENG to be applied in monitoring various human motions. This work offers a fresh perspective on material design, opening up new avenues for the development of high-performance PENGs.