The tunable conduction of coumarin-based composites has attracted considerable attention in a wide range of applications due to their unique chemical structures and fascinating properties. The incorporation of graphene oxide (GO) further enhances coumarin properties, including strong fluorescence, reversible photodimerization, and good thermal stability, expanding their potential use in advanced technological applications. This review describes the developmental evolution from GO, GO-polymer, and coumarin-based polymer to the coumarin-GO composite, concerning their synthesis, characterization, unique properties, and wide applications. We especially highlight the outstanding progress in the synthesis and structural characteristics along with their physical and chemical properties. Therefore, understanding their structure-property relations is very important to acquire scientific and technological information for developing the advanced materials with interesting performance in optoelectronic and energy applications as well as in the biomedical field. Given the expertise of influenced factors (e.g., dispersion quality, functionalization, and loading level) on the overall extent of enhancement, future research directions include optimizing coumarin-GO composites by varying the nanofiller types and coumarin compositions, which could significantly promote the development of next-generation polymer composites for specific applications.

Cobalt-based sulfides have emerged as promising candidates for next-generation high-performance anode materials for lithium-ion batteries (LIBs) due to their high theoretical specific capacity and reversible conversion reaction mechanisms. However, their practical application is hindered by volume expansion effects and relatively low rate performance. Guided by theoretical principles, this study synthesizes nanoscale Bi/CoS-C and Bi/Co₄S₃-C (denoted as Bi/CS-C) composite materials using Co and Bi₂S₃ as precursors via a solid-state ball milling method. The electrochemical properties of these materials were systematically investigated. When employed as anodes for LIBs, Bi/CoS-C and Bi/CS-C exhibit excellent rate capabilities. At current densities of 0.1, 0.5, 1, 4, and 10 A/g, the reversible capacities of Bi/CoS-C were 939.2, 730.7, 655.6, 508.1, and 319 mAh/g, respectively. In contrast, Bi/CS-C exhibited reversible capacities of 760.4, 637.6, 591.9, 484.3, and 295.4 mAh/g, respectively. Moreover, Co₄S₃, as an active component, enables superior long-cycle performance compared to CoS. After 300 cycles at 0.2 A/g, the Bi/CoS-C and Bi/CS-C electrodes retained capacities of 193.1 and 788.8 mAh/g, respectively. This study demonstrates that nanostructure design and carbon-based composite materials can effectively mitigate the volume expansion issue of cobalt-based sulfides, thereby enhancing their rate performance and cycling stability. This strategy provides new insights for the development of high-performance anode materials for lithium-ion batteries and is expected to accelerate their practical application in next-generation energy storage devices.

Carbon based materials are really an integral component of our lives and widespread research regarding their properties was conducted along this process. The addition of dopants to carbon materials, either during the production process or later on, has been actively investigated by researchers all over the world who are looking into how doping can enhance the performance of materials and how to overcome the current difficulties. This study explores synthesis methods for nitrogen-doped carbon materials, focusing on advancements in adsorption of different pollutants like CO₂ from air and organic, inorganic and ions pollutants from water, energy conversion, and storage, offering novel solutions to environmental and energy challenges. It addresses current issues with nitrogen-doped carbon materials, aiming to contribute to sustainable solutions in environmental and energy sciences. Alongside precursor types and synthesis methods, a significant relationship exists between nitrogen content percentage and adsorption capacity in nitrogen-doped activated carbon. Nitrogen content ranges from 0.64% to 11.23%, correlating with adsorption capacities from 0.05 mmol/g to 7.9 mmol/g. Moreover, an electrochemical correlation is observed between nitrogen atom increase and specific capacity in nitrogen-doped activated carbon electrodes. Higher nitrogen percentage corresponds to increased specific capacity and capacity retention. This comprehensive analysis sheds light on the potential of nitrogen-doped carbon materials and highlights their significance in addressing critical environmental and energy challenges.

Gold nanoparticles (AuNPs) have been known to possess exceptional electric, biochemical, and optical characteristics and are ‘the topic of discussion’ these days, especially relating to the field of biomedicine. Several plants, bacteria, and fungi have been utilized for the generation of AuNPs, besides other physical and chemical methods. While some studies have been reported with gold nanoparticles, less are aimed at fungi and its optimization factors. These parameters can allow us to design AuNPs of our choice depending on the use. The present review focuses on and inspects AuNPs with green synthesis through fungus optimization parameters followed by applications, aiming specifically at their antibacterial activity. Their antibacterial characteristics can open new doors for the pharmaceutical industry in the future.