High-performance redox-active organic molecule grafted graphene based on-chip micro-supercapacitor towards self-powered environmental monitoring station

In today's tech-centric world, miniaturized electronics like the Internet of Things (IoTs) and micro-sensory systems gained significant attention in both academic and industrial domains. Nonetheless, developing maintenance-free miniature power cells that can meet the requisite metrics for powering these microelectronics remains a crucial challenge. Herein, we proposed a p-phenylenediamine (PPD) grafted graphene supercapacitor electrode through a solvothermal grafting process. The redox-active properties of PPD molecules enhance the graphene electrode with exceptional pseudocapacitance via reversible redox reaction, resulting in a specific capacitance of 573.7 Fg−1, which is higher than the pristine rGO electrode. Benefiting from these properties, we have fabricated the on-chip micro-supercapacitor (MSC) through a laser-scribing technique, offering a wide working voltage (1.2 V) and superior capacitance of 38.4 mF cm−2 in an aqueous gel electrolyte. It is worth noting that the energy (7.6 μWh cm−2) and power density (4.46 mW cm−2) of this device are capable of empowering the various micro-sensors. As a proof of concept, we fabricated the self-powered environmental monitoring station integrating the MSC module and anemometer to recover the wind energy. The fabricated MSCs are self-charged up to their optimum potential (2.4 V within ∼ 225 sec) and empowered the micro-sensory system effectively (over ∼ 15 min), making it an ideal choice for near-future self-powered microelectronics.