For energy-related applications such as solar cells, catalysts, thermo-electrics, lithium-ion batteries, graphene-based materials, supercapacitors, and hydrogen storage systems, nanostructured materials have been extensively studied because of their advantages of high surface to volume ratios, favorable transport properties, tunable physical properties, and confinement effects resulting from their nanoscale dimensions. Due to their high energy and power densities, supercapacitors are potential power storage technologies. In this case, carbon nanomaterials, in particular carbon nanotubes, graphene, mesoporous carbon, and their hybrids, have received extensive research interest as effective electrode materials for supercapacitors because of their distinctive hierarchical structure, excellent electrical and mechanical properties, and large specific surface area. Lithium-ion batteries (LIBs) have been receiving extensive attention because of their high specific energy density. In LIBs, graphite is the most commonly used anode material; however, lithium-ion intercalation in graphite is limited, hindering the battery charge rate and capacity. Recently, nanowire/graphene hybrids have been developed for the enhancement of the LIB performance; therefore, we present a new approach of hydrothermally growing uniform nanowires on a graphene aerogel to further improve the performance. This nanowire/graphene aerogel hybrid not only exhibited the large surface area of graphene aerogels but also increased the specific surface area for electrode–electrolyte interaction. Therefore, this new nanowire/graphene aerogel hybrid anode material can enhance the specific capacity and charge–discharge rate. There is enormous interest in the use of graphene-based materials for energy storage. Graphene-based materials have great potential for application in supercapacitors owing to their unique two-dimensional structure and inherent physical properties, such as excellent electrical conductivity and large specific surface area. In recent years, the development of different organic and inorganic nanostructured materials such as nanocarbons, metal oxides (W₁₈O₄₉ and Co₃O₄), metal sulphides (MoS₂ and WS₂), graphene nanosheets, and conducting polymers has enabled the fabrication of high-performance devices. MoS₂, a typical layered transition-metal dichalcogenide material, has attracted significant attention for application in heterogeneous catalysis, lithium ion batteries and electrochemical energy storage systems considering its unique layered structure and electronic properties. Thus, transition metal dichalcogenide nanomaterials have shown important research progress in the field of energy conversion and storage.

The design of sustainable and efficient materials for efficient energy storage and degradation of environmental pollutants (specifically organic dyes) is a matter of major interest these days. For this purpose, cerium- and ytterbium-based GO/g-C₃N₄/Fe₂O₃ composites have been synthesized to explore their properties, especially in charge storage devices such as supercapacitors, and also as photocatalysts for the degradation of carcinogenic dyes from the environment. Physicochemical studies have been carried out using XRD, FTIR, SEM, and BET techniques. Electrochemical techniques (cyclic voltammetry, galvanic charge discharge, and electrochemical impedance spectroscopy) have been employed to measure super-capacitance and EDLC properties. Results show that the gravimetric capacitance calculated from GCD results is 219 Fg⁻¹ for ytterbium- and 169 Fg⁻¹ for cerium-based nanocomposites at the current density of 1 A/g and scan rate of 2 mV/sec. The specific capacitance calculated for the ytterbium-based nanocomposite is 189 Fg⁻¹ as compared to 125 Fg⁻¹ for the cerium-based material. EIS results pointed to an enhanced resistance offered by cerium-based nanocomposites as compared to that of ytterbium, which can be assumed with the difference in particle size, as confirmed from structural studies including XRD. From obtained results, ytterbium oxide-based GO/g-C₃N₄/Fe₂O₃ is proven to be a better electro-catalyst as compared to cerium-based nanocomposites. Photocatalytic results are also in agreement with electrochemical results, as the degradation efficiency of ytterbium oxide-based GO/g-C₃N₄/Fe₂O₃ (67.11 and 83.50% for rhodamine B and methylene blue dyes) surpasses values observed for cerium-based GO/g-C₃N₄/Fe₂O₃ (63.08 and 70.61%).

Graphene-based materials have garnered significant interest in the burgeoning field of contemporary flexible and bendable technologies. Graphene has emerged as a prime candidate for the development of flexible electronics due to its outstanding electrical, mechanical, and optical properties, coupled with the ease of functionalizing its derivatives. This review provides an exhaustive analysis of the latest advancements in the synthesis and applications of graphene-based composites.Exceptional properties of Graphene including high thermal conductivity, chemical stability, optical transparency, high current density, and increased surface area, have broad implications across thermodynamics, chemistry, optics, and mechanics. The growing use of graphene oxide materials across various industries has fueled a surge in interest. The synthesis of graphene oxide compounds follows established procedures such as those by Brodie, Staudenmaier, and Tour, with ongoing discussions on large-scale production using various oxidants. Recent developments have led to numerous new, enhanced, and modified Hummers techniques for producing graphene oxide.Graphene oxide (GO) serves as a crucial foundational material for a wide range of applications, including energy storage, water purification, and as a composite in biosensors, electronics, and hazardous gas removal. This review delves into these applications, highlighting GO’s role in improving the efficiency and performance of these technologies. Additionally, the paper addresses the current challenges and obstacles in the development and application of graphene, providing insights into potential solutions and future research directions.By offering a comprehensive and practical database, this review aims to facilitate the future development of graphene-based composite materials, driving innovation and advancements in various high-impact applications.

Neurotransmitters are essential chemical messengers required for proper brain function, and any changes in their concentrations can lead to neuronal diseases. Therefore, sensitive and selective detection is crucial. This study presents a fast and simple colorimetric method for dopamine detection using three reagent solutions: AgNP and MPA, Ag/Au nanocomposite, and mercaptophenylacetic acid. TEM images showed a narrow distribution of Ag and Au nanoparticles with average sizes of 20 nm and 13 nm, respectively, with gold nanoparticles bound to the edges of silver nanoparticles. A paper-based biosensor was created using manual wax printing for the colorimetric detection of dopamine. Visual detection onsite showed color changes with both the silver nanoparticles and mercaptophenylacetic acid mixture and the silver–gold nanoparticle composite. Electrochemical detection using a glassy carbon electrode modified with 8 mM mercaptophenylacetic acid demonstrated high selectivity and sensitivity towards dopamine, with a peak in the range of 0.7–0.9 V. Interferences were minimized, ensuring high sensitivity and selective detection of dopamine.

Recent advancements have focused on developing innovative and renewable technologies for energy production and storage. Batteries are regarded as an affordable, practical, and effective way to meet the growing needs for energy storage. Nanocomposite materials hold significant promise for both research and practical applications because of their superior performance, diverse composition, and structural benefits. NaCrSnNiCeO₂ and NaCuFeNiCeO₂ nanocomposites bring scientific innovation due to their peculiar structure, which incorporates cerium and multimetal synergy to enhance the electrochemical parameters. This research can pave the way for the use of these multimetal oxides as advanced electrode materials in energy storage systems by elucidating the effect of cation substitutions, such as Cu, Cr, Fe, and Sn, on their structure, conductivity, and redox activity. In particular, multi-component nanocomposites possess distinct features that make them beneficial for energy storage systems. In this work, NaCrSnNiCeO₂ and NaCuFeNiCeO₂ nanocomposites were synthesized via the sol–gel approach. The characterization of the prepared nanocomposites was done by employing FTIR, XRD, XPS, and SEM techniques, while the electrochemical performances of the prepared samples are analyzed by utilizing CV, GCD, and EIS techniques. The results clearly demonstrated that the NaCuFeNiCeO₂ nanocomposite was a better electrode material and exhibited higher specific capacity of 366.7 C g⁻¹, compared to the NaCrSnNiCeO₂ nanocomposite, 233.6 C g⁻¹. Employing advanced synthesis methods and extensive characterization, the paper demonstrates a specific capacitance and energy density that is higher than normal along with an increased cycling stability. Furthermore, a focus on economical and abundant feedstock and green chemistry in this research aims at formulating sustainable answers for next-generation energy storage technologies. This work is anticipated to become a significant milestone in improving charge storage capabilities, setting the foundation for the development of high-performance energy storage systems in the future.