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A supercapattery is an advanced energy storage device with superior power and energy density compared to traditional supercapacitors and batteries. A facial and single-step hydrothermal method was adopted to synthesize the rGO/GQDs doped Fe-MOF nano-composites. The incorporation of the dopants into the host material was to improve the energy storage capacity and improve cyclic stability. The structural, morphological, and compositional analyses were conducted by employing X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Additionally, Brunauer–Emmett–Teller (BET) measurements were used to calculate the nanomaterial's surface area and pore size. Dunn's model was used to demonstrate the contributions of the capacitive and diffusive components of the asymmetric energy storage structure. Fe-MOF/rGO/GQDs have a higher specific capacity (1876 C/g) than pure Fe-MOF (705 C/g) at 1.0 A/g current density. The Fe-MOF/rGO/GQDs supercapattery retained 95% of its capacity after 5000 charging and discharging cycles to test the asymmetric device durability. The power and energy densities have been determined to be 1160 W/kg and 57 Wh/kg, respectively. Fe-MOF showed excellent electrocatalytic activity in the hydrogen evolution process (HER) with a declined Tafel slope of 47.27 mV/dec. The Fe-MOF/rGO/GQDs electrode exhibits the lowest overpotential of 278 mV at 10 mA cm−2 with a Tafel slope of roughly 49.2 mV dec−1 in its function as an oxygen evolution reaction (OER) catalyst. This research work provides a basis for improving the efficiency of energy storage technologies. [ABSTRACT FROM AUTHOR]

This work reports an extensive study of the effect of the SiC polytypes substrate on the electrical properties of heterostructures based on SiC and polyaniline (PANI) employing current–voltage (I–V), capacitance–voltage (C–V) and deep-level transient spectroscopy (DLTS) techniques. Two different SiC substrates, namely 4H-SiC and 6H-SiC, have been investigated. The I–V results revealed that the rectification ratio (IF/IR), turn-on voltage (Von) and barrier height (ϕbo) of PANI/4H-SiC hybrid device are higher than those for PANI/6H-SiC heterojunctions. The C–V measurements illustrated that the built-in potential (Vbi) of PANI deposited on 4H-SiC is greater than that of the PANI sample fabricated on 6H-SiC. Furthermore, the DLTS results showed that the energy of electrically active traps present at/close and away from the interface in devices based on the 4H-SiC substrate is lower than those of 6H-SiC substrates, corroborating with I–V results. [ABSTRACT FROM AUTHOR]