Structural optimizations of the piezoelectric layer in nanogenerators have been predicted to enhance the output performance in terms of the figure of merit. Here, we report the effect of dielectric constant on electrical outputs of piezoelectric nanogenerator using ZnO/PDMS composites with varied ZnO coverages. The dielectric constant of piezoelectric layers was adjusted from 3.37 to 6.75. The electrical output voltage of 9 mV was achieved in the nanogenerator containing the ZnO/PDMS composite with the dielectric constant of 3.46, which is an 11.3-fold enhancement compared to the value of the nanogenerator featuring the composite with high dielectric constants. Significantly, lowering the dielectric constant of the piezoelectric layer improves the electrical output performance of piezoelectric nanogenerators.

Triboelectric nanogenerators possessing polymeric contact electrification layers have been a state‐of‐the‐art technology for portable and wearable applications, but the intrinsic low permittivity of polymers has posed a significant charge loss, limiting the electrical outputs from the nanogenerators. The incorporation of conductive fillers into the polymer matrix represents a promising route to enhance the dielectric constant of polymers while remaining the surface properties, but the geometric influence of fillers is yet to be uncovered. Herein, the cooperativity of silver nanostructures with differing geometry on triboelectric power generation in polyimide film layers is reported. Upon implementation of silver nanorods into a polymer film, the dielectric constant is improved a 2.5‐fold compared to the pristine polymer film, resulting in a remarkable enhancement of up to 830% in output power of the nanogenerators.

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We prepared ZnO nanocomposites with WO3 or CuO nanostructures to improve the photocatalytic performance of ZnO nanostructures. Characterization of the nanocomposites using scanning electron microscopy, x-ray diffraction, UV–vis spectrometry and photoluminescence revealed the morphologies and wide light absorption range of the materials. The highest current densities of WO3/ZnO and CuO/ZnO nanocomposites were 1.28 mA cm−2 and 2.49 mA cm−2 at 1.23 V (versus a reversible hydrogen electrode) under AM 1.5 100 mW cm−2, which are ~1.2- and 3.5-fold greater than those of bare ZnO nanostructures, respectively. The easy fabrication process suggests that nanocomposites with narrow bandgap materials, such as WO3 and CuO, will improve the performance of electrochemical and optoelectrical devices such as dye-sensitized solar cells and biosensors.