www.advenergymat.de FULL PAPER 1803581 (1 of 8) © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Metal–Organic Framework: A Novel Material for Triboelectric Nanogenerator–Based Self-Powered Sensors and Systems Gaurav Khandelwal, Arunkumar Chandrasekhar, Nirmal Prashanth Maria Joseph Raj, and Sang-Jae Kim* DOI: 10.1002/aenm.201803581 energy. To overcome the disadvantages of conventional energy technology, and for the development of sustainable energy sources, Wang and co-workers introduced an efficient triboelectric nanogenerator (TENG) in 2012. [1] The TENG can con- vert various types of energy, e.g., mechan- ical, wind, and water, into electricity. [2] The TENG works in four modes, i.e., freestanding, vertical contact-separation, lateral sliding, and single electrode modes, via utilization of contact electrification and electrostatic induction. [3] Cost effective- ness, easy design, large output power, and high conversion efficiency are among the key advantages of TENG. [3] The growing demand for wearable electronics, self-powered sensors, e-skin, and sustainable and flexible devices has led to rapid developments in TENG- related technologies. [4] Materials that dem- onstrate triboelectric charging include various polymers and a few metals. [5] Output performance, triboelectric material, and stability are critical for the development of optimized, functional, and sus- tainable TENG devices. The metal–organic framework (MOF), composed of a metal ion coordinated with an organic ligand, have yet to be investigated as potential TENG components. MOFs provide flexibility regarding the size, functionality, and geometry of the TENG, which makes them ideal candidates for many applications such as gas sensors, biosensors, drug delivery, fuel storage, catalysis, and adsorbance. [6] The porous structure of the MOF provides a high surface area to improve the functionality of TENG devices. Thus, careful selection of the MOF component can yield a crystal framework with high porosity and high chemical and thermal stability. [6] Moreover, the ability to expand their metrics and achieve chemical modi- fication without changing the topology are added advantages, promoting high-output performance, and sensing and func- tional applications. [6] To our knowledge, herein we introduce for the first time an MOF-based TENG (MOF–TENG) for self-powered system and sensor applications. The subclass zeolitic imidazole frame- work (ZIF) of the MOF, having the topology of an inorganic zeolite with a sodalite (SOD) structure, has a small aperture and large pores. [7] In this work, ZIF-8, a unique framework The triboelectric nanogenerator (TENG) offers a simple and cost-effective method to harness waste energy and works on the principle of contact electrification and electrostatic induction. The performance and application of TENG depend to a great extent on the material used for fabrication. The most widely used materials include polymers and a few metals, well-arranged in the triboelectric series so as to promote electrification upon contact. New triboelectric materials are important for extending the applications and specificity of the TENG. A TENG based on a metal–organic framework (MOF) of the zeolitic imidazole family is reported here. The zeolitic imidazole framework-8 (ZIF-8) and Kapton are used as the active materials for MOF– TENG fabrication. Surface potential, structural, morphological and electrical measurements reveals detailed characteristics of ZIF-8, confirming the MOF as a potential candidate for TENG applications. The MOF–TENG generates a sustainable output of 164 V and 7 μA in vertical contact–separation mode. Finally, a self-powered UV counterfeit system and a tetracycline sensor are successfully developed and demonstrated with the MOF–TENG. The sensor is highly selective and reusable simply by washing. G. Khandelwal, Dr. A. Chandrasekhar, N. P. Maria Joseph Raj, Prof. S.-J. Kim Nanomaterials and System Lab Department of Mechatronics Engineering Jeju National University Jeju 690-756, South Korea E-mail: kimsangj@jejunu.ac.kr Dr. A. Chandrasekhar Department of Sensor and Biomedical Technology School of Electronics Engineering Vellore Institute of Technology Vellore 632014, India The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/aenm.201803581. ZIF-8 Energy Harvester 1. Introduction Nature provides ample sources of energy, such as solar, wind, water, and mechanical energy, which, if exploited, can serve as a partial solution to the depleted state of fossil fuels and the energy crisis. With greater environmental awareness and numerous technological advances, there is a growing market for electronics based on the utilization of clean and abundant Adv. Energy Mater. 2019, 1803581