Highly Charge-Trapping MOF Nanofillers Enabling Enhanced Triboelectric Performance

Metal–organic frameworks (MOFs) have been used in triboelectric nanogenerators (TENGs) to improve the output performance because of their designability and great triboelectricity. However, there still lacks detailed and systematic research about the influence of the morphology of MOFs to the outputs of TENGs. Here, ZIF-67 particles with three different sizes were successfully prepared and filled with silk fibroin (SF) to prepare composite films. TENGs composed of ZIF-67/SF composites were assembled and tested. Results indicated that the output of the TENGs was very sensitive to filler particle size and mass ratios. Owing to the much higher charge-trapping property, ZIF-67 with the smallest particle size (500 nm) increased the output power density by 5 times with the value of 144 μW cm–2. With the enhanced output power density, TENGs based on ZIF-67/SF composite films were applied more widely for harvesting mechanical energy in real life.