Synergistic integration of graphene quantum dots into metal–organic framework-5 for enhancing triboelectric nanogenerator performance

Recently, there has been a noteworthy development in the realm of metal–organic frameworks (MOFs) showcasing their potential as efficient materials for triboelectric nanogenerators (TENGs) designed to harvest ambient mechanical energies. Hence, many researchers are trying to synthesize a new cubic metal–organic framework (MOF-5) applied composite for TENG. To address this challenge, a strong electron-donating surface functional group is introduced herein. This paper designs and synthesizes MOF-5 integrated with graphene quantum dots (GQDs) through a surface modification doping strategy. Here, the incorporation of oxygen-containing functional groups within GQDs into MOF-5 (GQDs@MOF-5) boasts strong electron positivity to lead to a significant enhancement in the electrical output of MOF-5-based TENG. In addition, these functional groups allow tailored interactions with metal ions and organic ligands in MOF-5, creating additional pores and channels within GQDs@MOF-5 and enhancing its overall performance. Since the GQDs@MOF-5 has improved surface properties and electron-donating capabilities, the proposed TENG is achieving a remarkable eight-fold increase (~378.51 μW/cm² to ~2971.80 μW/cm²), in power density compared with unmodified MOF-5 TENGs. Notably, the voltage and current outputs have reached record highs at ~885 V and ~84 µA, respectively. The proposed GQDs@MOF-5-based TENG can be applied to various applications such as energy harvesting, physiological motion monitoring, and vehicle speed recognition. The proposed work can also open a new gate enhancing oxygen vacancies and porosity in triboelectrification.