A schematic of an electrochemical flow capacitor device, in which graphene-based slurries were used as flow liquids.

In this study spinel‐lithium manganese oxide (LiMn2O4) powders were prepared by using a simple sol–gel method with polyvinyl alcohol (PVA), and further combined with a conductive additive, graphene, to produce a composite electrode material for improved performance. The effects of the variation in the ratios of binder (PVA) to LiMn2O4 precursor on the particle size and electrochemical behavior of the composite were studied. Particle sizes of <200 nm were obtained. An energy density of 17.36 Wh kg−1 was obtained at an operating voltage of 3.2 V for the pure LiMn2O4 sample tested against a graphene electrode. For simultaneously improving power density (current Li batteries have a low power density as a disadvantage) along with energy density, the LiMn2O4–graphene composite was chosen as an electrode material. LiMn2O4–graphene composite electrodes were prepared by electrophoretic co‐deposition. The ratio of LiMn2O4–graphene composite was optimized to 1:1 during the electrode study based on its electrochemical performance. An average energy density of 30 Wh kg−1, a specific capacity of 49 mAh g−1, and an enhanced power density of 800 W kg−1 at a discharge current of 0.5 A g−1 were obtained. Discharge behavior improved evidently for tests performed on composite electrodes with increased LiMn2O4 (1:1.3 graphene/LiMn2O4). An improved average energy density of 59.6 Wh kg−1 was obtained along with a power density of 697 W kg−1. The electrodes showed good performance during study of a button cell device. Such electrodes are well suited for hybrid energy storage devices having good energy and power density and bridging the gap between batteries and supercapacitors.

In this perspective article, we discuss the possibilities of integrating liquefied organic and inorganic semiconducting materials with tunable optoelectronic properties into solvent-free fluidic systems of functional optoelectronic materials to generate flexible DSSCs/QDSSCs.

Energy storage is a key aspect in the smooth functioning of the numerous gadgets that aid easy maneuvering through modern life. Utilization of waste materials for energy storage applications enables the sustainable development of energy field.

An iron oxide based-electroactive IoNanofluid with a high dielectric constant, high stability and low viscosity was synthesized from ferrous sulphate heptahydrate via a facile microwave assisted one-step route in 1-butyl-4-methylpyridinium chloride.

TiO 2 nanoparticles surface-modified with silane moieties, which can be directly coated on a flexible substrate without the requirement of any binder materials and postsintering processes, are synthesized and characterized using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, Brunauer–Emmett–Teller, X-ray photoelectron spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, time-correlated single-photon counting, and transmission electron microscopy. The viability of the prepared surface-modified TiO 2 (M-TiO 2 ) sheets as a catalyst for the photo-induced degradation of a model dye, methylene blue, was checked using UV–visible absorption spectroscopy. The data suggest that, compared to unmodified TiO 2 , M-TiO 2 sheets facilitate better dye-degradation, which leads to a remarkable photocatalytic activity that results in more than 95% degradation of the dye in the first 10 min and more than 99% of the degradation in the first 50 min of the photocatalytic experiments. We also demonstrate that M-TiO 2 can be recycled with negligible reduction in photocatalytic activity. Further, the photovoltaic properties of the developed M-TiO 2 sheets were assessed using UV–visible absorption spectroscopy, electrochemical impedance spectroscopy (EIS), and photochronoamperometry. Dye-sensitized solar cells (DSSC) fabricated using M-TiO 2 as the photoanode exhibited a photoconversion efficiency of 4.1% under direct sunlight. These experiments suggested that M-TiO 2 sheets show enhanced photovoltaic properties compared to unmodified TiO 2 sheets, and that, when N-719 dye is incorporated, the dye–TiO 2 interaction is more favorable for M-TiO 2 than bare TiO 2 . The simple solution processing method demonstrated in this paper rendered a highly flexible photoanode made of M-TiO 2 with superior charge-separation efficiency to an electrode made of bare TiO 2 . We propose that our findings on the photovoltaic properties of M-TiO 2 open up arenas of further improvement and a wide scope for the large-scale production of flexible DSSCs on plastic substrates at room temperature in a cost-effective way.

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