Interest in carbon quantum dots (CQDs) has recently boomed due to their potential to enhance the performance of various solar technologies as nontoxic, naturally abundant, and cleanly produced nanomaterials. CQDs and their other variations, such as nitrogen-doped carbon quantum dots (NCQDs) and graphene quantum dots (GQDs), have improved the performance of luminescent solar concentrators (LSCs) and photovoltaic (PV) cells due to their excellent optical properties. As fluorophores in LSCs, CQDs are mostly transparent to visible light and have absorption/re-emission spectra that can be easily controlled. The outstanding optical properties of CQDs make them promising materials to replace expensive, heavy-metal-based fluorophores. Various CQDs have also been used as or doped into the photoanode, counter electrode, hole transport layer (HTL), and electron transport layer (ETL) of dye-sensitized solar cells (DSSCs), organic solar cells (OSC), perovskite solar cells (PSCs), and other PV cell configurations. The addition of CQDs into the various solar cell components has reduced electron recombination, increased charge density, and boosted electron mobility, improving the performance of the PV cells. Enhancing the power conversion efficiency (PCE) of photovoltaic devices is essential in propagating green energy technology. Thus, CQDs offer an affordable, safe, and environmentally friendly method to advance photovoltaic performance.

Luminescent solar concentrators (LSCs) have recently gained popularity as an effective solution to increase solar energy conversion. Utilizing LSCs together with solar cells can generate more energy at a lower cost than using only solar cells. LSCs operate by utilizing luminophores, molecules that absorb incident solar irradiation and re‐emit photons, and waveguides that redirect emitted photons to the edges of a glass or polymer slab at high concentrations. Many quantum dots (QDs) have been the focus of much research as luminophores for LSCs, owing to their high quantum yields (QYs), controllable absorption/emission spectra, good stability, and ease of synthesis. Various QDs, such as CdSe, PbS, CdS, AgInS2, Si, and C, have been modified to enhance their optical performances in LSCs, often measured by their optical efficiencies, internal/external quantum efficiencies, and power conversion efficiencies. This review appraises the latest developments in colloidal QDs—basic QDs, doped QDs, core/shell QDs, hybrid QDs, and Si‐based QD—for their applications in LSCs. Other factors that enhance an LSC's efficiency, such as altering the polymer matrix and using distributed Bragg reflectors, are discussed. The development of highly efficient, QD‐based LSCs will be essential for increasing solar energy production worldwide.

Layered double hydroxides (LDHs) have attracted considerable attention as promising materials for electrochemical and optical sensors owing to their excellent catalytic properties, facile synthesis strategies, highly tunable morphology, and versatile hosting ability. LDH-based electrochemical sensors are affordable alternatives to traditional precious-metal-based sensors, as LDHs can be synthesized from abundant inorganic precursors. LDH-modified probes can directly catalyze or host catalytic compounds that facilitate analyte redox reactions, detected as changes in the probe’s current, voltage, or resistance. The porous and lamellar structure of LDHs allows rapid analyte diffusion and abundant active sites for enhanced sensor sensitivity. LDHs can be composed of conductive materials such as reduced graphene oxide (rGO) or metal nanoparticles for improved catalytic activity and analyte selectivity. As optical sensors, LDHs provide a spacious, stable structure for synergistic guest–host interactions. LDHs can immobilize fluorophores, chemiluminescence reactants, and other spectroscopically active materials to reduce the aggregation and dissolution of the embedded sensor molecules, yielding enhanced optical responses and increased probe reusability. This review discusses standard LDH synthesis methods and overviews the different electrochemical and optical analysis techniques. Furthermore, the designs and modifications of exemplary LDHs and LDH composite materials are analyzed, focusing on the analytical performance of LDH-based sensors for key biomarkers and pollutants, including glucose, dopamine (DA), H2O2, metal ions, nitrogen-based toxins, and other organic compounds.

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With the increasing energy demand for portable electronics, electric vehicles, and green energy storage solutions, the development of high-performance supercapacitors has been at the forefront of energy storage and conversion research. In the past decade, many scientific publications have been dedicated to designing hybrid electrode materials composed of vanadium pentoxide (V2O5) and carbon nanomaterials to bridge the gap in energy and power of traditional batteries and capacitors. V2O5 is a promising electrode material owing to its natural abundance, nontoxicity, and high capacitive potential. However, bulk V2O5 is limited by poor conductivity, low porosity, and dissolution during charge/discharge cycles. To overcome the limitations of V2O5, many researchers have incorporated common carbon nanostructures such as reduced graphene oxides, carbon nanotubes, carbon nanofibers, and other carbon moieties into V2O5. The carbon components facilitate electron mobility and act as porous templates for V2O5 nucleation with an enhanced surface area as well as interconnected surface morphology and structural stability. This review discusses the development of various V2O5/carbon hybrid materials, focusing on the effects of different synthesis methods, V2O5/carbon compositions, and physical treatment strategies on the structure and electrochemical performance of the composite material as promising supercapacitor electrodes.

Lithium–sulfur batteries (LSBs) are one of the most promising next-generation batteries because they have higher theoretical capacities, lower cost, and smaller environmental impact than lithium-ion batteries (LIBs).

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power-dense, owing to their tuneable nanostructures. Hence, smaller TENGs are better suited for small form-factor applications like wearable electronics, internet of things (IoT) devices, and self-powered sensors. However, the higher complexity and cost of TENGs than TEGs inhibit their widespread adoption. This review appraises the latest advances in TENG materials, design, and fabrication in optimizing the performance of TENGs, making TENGs more viable for real-world applications. More precisely, this work examines how nanostructure engineering, nanomaterial compositing, and post-synthesis treatment approaches have enhanced the TE properties of common and promising TE materials, including tellurides, selenides, metal oxides, metal alloys, silicon, carbon nanomaterials, and organic compounds. Given that the TE material is a key component in TENGs, this review highlights how to optimize other vital parameters, including the TENG configuration, contact interface, form factor, heat sink use, and folded shape for specific applications. Lastly, critical attributes of TENGs used in wearable electronics, sensors, implantable electronics, solar energy conversion, and waste heat recovery are analyzed.