In this modern era of electronics possessing features like advanced compactness and wearability, flexible all-solid-state supercapacitor devices constructed by using biomass-derived materials are considered as suitable aspirants by virtue of their high energy density, power density, and good cyclic life. Herein, we have constructed a high-performance all-solid-state flexible asymmetric supercapacitor device using coconut fiber derived porous carbon as the anode and a nanocomposite composed of CoFe 2 O 4 nanoparticles (CF) immobilized within the pores of porous carbon (PC) as the cathode. The constructed device possessed a high energy density of 50.34 W h kg −1 at a power density of 1450 W kg −1 and good cycle life (retention of ∼91% specific capacitance (C S ) after ∼5000 cycles). The fabricated device retained its performance even after considerable physical deformation. These excellent features of this device can be credited to the synergy between the CF and PC nanomaterials. CF nanoparticles provide fast redox processes and good power delivery within a few seconds of time, whereas the high surface area (BET surface area ∼1323 m 2 g −1 ) porous carbon possessing structural porosity hosts the CF nanoparticles and also helps in faster ion transfer in the nanocomposite and provides mechanical robustness to the electrode. The results obtained from the present work encourage the augmentation of low-cost electrode material for highly efficient green energy-based electrochemical energy storage (EES) devices.

Magnetic CoFe2O4–gC3N4 nanocomposites were successfully synthesized, and their photocatalytic activities toward the decomposition of model synthetic dyes (e.g., methylene blue, methyl orange, and Congo red) in the presence of H2O2 were evaluated under simulated solar light irradiation. The 50CoFe2O4–50gC3N4 nanocomposite exhibited the highest catalytic activity. The catalytic activity of 50CoFe2O4–50gC3N4 toward the photodegradation of some industrially used dyes (such as Drimaren Turquoise CL-B p, Drimaren Yellow CL-2R p, and Drimaren Red CL-5B p) was also examined, and the catalyst exhibited its capability to decompose the industrial dyes completely. An aqueous mixture of these dyes was prepared to mimic the dye-containing wastewater, which was fully photodegraded within 30 min. 50CoFe2O4–50gC3N4 also exhibited facile magnetic separability from the reaction mixture after the accomplishment of photocatalysis reaction and stable performance after five cycles. The high photocatalytic efficiency to degrade several dyes, including dyes used in textile industries, under solar light irradiation makes 50CoFe2O4–50gC3N4 a promising photocatalyst for the treatment of dye-containing wastewater discharged from industries.

The energy demand, the crisis of fossil fuels, and the increasing popularity of portable and wearable electronics in the global market have triggered the demand to develop high-performance flexible all-solid-state supercapacitors that are capable of delivering high energy at high power density as well as being safely entrenched in those electronics. Herein, we have designed a nanocomposite, 80CF hs -20rGO sp , which exhibits a high specific capacitance ( C S ) value of 1032 F g –1 at 3 A g –1 . Utilizing this nanocomposite as the cathode and reduced graphene oxide sponge (rGO sp ) as the anode, a flexible all-solid-state asymmetric device has been fabricated. In this device, poly(vinyl alcohol) (PVA) gel embedded with a mixture of 3 M KOH and 0.1 M K 4 [Fe(CN) 6 ] was used as an electrolyte cum separator. The fabricated device showed the capability to deliver an energy density of 65.8 W h kg –1 at a power density of 1500 W kg –1 and retained its capability even after various physical deformations. The device also exhibited a long cycle life and retained ∼96% of its C S value after 5000 cycles. Moreover, the fabricated flexible all-solid-state device successfully illuminated light-emitting diodes, which proved its potential use in real-life supercapacitor applications. The obtained results revealed the excellent electrochemical performances of the fabricated device and rendered it a promising candidate in the energy sector.

The periodic layered structure due to the well-arranged sheets and the presence of surface terminations (-OH, -O, and -F) on those sheets makes MXene an attractive aspirant for supercapacitor devices. Though MXene exhibits interesting redox behavior, the collapse of its layered structure and irreversible stacking of sheets retard its redox reaction and restrict the ion transport process. To enhance its electrochemical performance, we have developed a nanocomposite where the α-Ni­(OH)2 petals are slid within the MXene structure as well as anchored on its surface. The multivalent character of Ni in Ni­(OH)2 enhances the redox performance of the nanocomposite. Fabrication of a high-performance flexible all-solid-state asymmetric supercapacitor (ASC) device has been carried out using this 50MXene-50Ni­(OH)2 nanocomposite as the cathode and the biomass-derived porous carbon as the anode. This ASC device manifested a high energy density of 29.3 W h kg–1 at a power density of 800 W kg–1 and 90% retention of specific capacitance (C S) even after ∼5000 GCD cycles. This supercapacitor device also demonstrated its mechanically flexible feature by showing its consistent electrochemical performance in diverse physical deformations. This flexible device illustrated its competence in real-world applications by illuminating an assembly of LED lights.

The rising demand for portable and wearable electronics, biomedical implants, healthcare gadgets, etc., in the global market is triggering the augmentation of flexible supercapacitor devices that can supply sustainable but...

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Energy storage and environmental pollution are two major global concerns in today's scenario. As a result of the momentous exhaustion of fossil fuels, the generation of energy from renewable sources is gaining immense importance. However, the irregular availability of energy from these renewable sources is the major encounter to achieve sustainable energy harvesting technology, yielding efficient but continuous and reliable energy supplies. Apart from the requirement of state-of-the-art heavy-duty technologies such as transportation, defense, etc., in the modern lifestyle to fulfill the demand for flexible electronic devices, the development of high-performance mechanically flexible all-solid-state supercapacitors is increasing massively. On the other hand, to cater to the need for accessibility of clean water for healthy lives, several technologies are evolving to treat wastewater and groundwater. Hence, the development of efficient catalysts for destroying water pollutants is an attractive approach. Considering these two crucial facets, in this paper, we have demonstrated the multifunctional features of a CuFe 2 O 4 -rGO nanocomposite, which was exploited to fabricate a high-performance mechanically flexible all-solid-state asymmetric supercapacitor and simultaneously used as an efficient but easily recoverable catalyst for the transformation of different nitroaromatic compounds. We have also demonstrated the conversion of trifluralin (a herbicide), which is present in the water body as a pollutant, to its corresponding amine derivatives, which can be utilized in the preparation of important pharmaceutical products.