ZIF-62: a mixed linker metal-organic framework for triboelectric nanogenerators

Metal-organic frameworks (MOFs) offer unique advantages including high surface area, porosity, size flexibility, and easy modification. MOFs can be chemically modified without changing the topology. The appealing properties of MOFs led to their utilization for the fabrication of triboelectric nanogenerators (TENGs) and the expansion of the triboelectric series with multifunctional materials. Here, a mixed linker MOF ZIF-62 of the zeolitic imidazolate framework (ZIF) subfamily for TENG is reported. The structural and morphological analysis confirms the successful formation of ZIF-62. The Kelvin probe force microscopy (KPFM) and surface potential measurement reveal the positive potential on ZIF-62. Teflon, Kapton, and ethyl cellulose (EC) are used as the opposite triboelectric layers to ZIF-62. The ZIF-62 TENG follows an output trend of TENG Teflon > TENG Kapton > TENG EC. The ZIF-62/Teflon TENG generated an output voltage, current, and charge of 62 V, 1.4 mu A, and 16 nC, respectively. The fabricated device is demonstrated for fitness tracking and energy harvesting during numerous gym exercises such as hand curl, lateral raise, shoulder press, and squats. Finally, numerous low-power electronics is successfully powered with the output of ZIF-62 TENGviaa charged capacitor.