The exploration of novel polymers for temperature sensing with high sensitivity has attracted tremendous research interest. Hence, we report a polystyrene-coated optical fiber temperature sensor with high sensitivity. To enhance the temperature sensitivity, flat, thin, smooth, and air bubble-free polystyrene was coated on the edge surface of a single-mode optical fiber, where the coating thickness was varied based on the solution concentration. Three thicknesses of the polystyrene layer were obtained as 2.0, 4.1, and 8.0 μm. The temperature sensor with 2.0 μm thick polystyrene exhibited the highest temperature sensitivity of 439.89 pm °C⁻¹ in the temperature range of 25–100 °C. This could be attributed to the very uniform and thin coating of polystyrene, along with the reasonable coefficient of thermal expansion and thermo-optic coefficient of polystyrene. Overall, the experimental results proved the effectiveness of the proposed polystyrene-coated temperature sensor for accurate temperature measurement.

Modern industrialization has unleashed unprecedented environmental challenges, primarily in the form of pollution. In response to these pressing issues, the quest for innovative and sustainable solutions has intensified. Photocatalysis, with its unique capabilities, has emerged as a potent technology to combat the adverse effects of industrialization on the environment. This review highlights recent advances in harnessing photocatalysis to address environmental pollution. Photocatalysis offers a multifaceted approach, utilizing solar energy for catalytic reactions and enabling efficient pollutant removal. Quantum dots and graphitic carbon nitride (g-C₃N₄) are essential elements in this science. In contrast to quantum dots, which have enormous potential due to their size-dependent bandgap tunability and effective charge carrier production, g-C₃N₄ has properties like chemical stability and a configurable bandgap that make it a versatile material for photocatalysis. In this review, we explore recent achievements in integrating metal oxide quantum dots with g-C₃N₄, forming nanocomposites with superior photocatalytic activity. These nanocomposites exhibit extended light absorption ranges and enhanced charge separation efficiency, positioning them at the forefront of diverse photocatalytic applications. In conclusion, this comprehensive review underscores the critical role of photocatalysis as a potent tool to counteract the adverse environmental effects of modern industrialization. By emphasizing recent advancements in g-C₃N₄ and quantum dots and highlighting the advantages of metal oxide quantum dots decorated/integrated with g-C₃N₄ nanocomposites, this work contributes to the evolving landscape of sustainable solutions for environmental remediation and pollution control. These innovations hold promise for a cleaner and more sustainable future.

To develop an advanced anode for lithium-ion batteries, the electrochemical performance of a novel material comprising a porous artificial carbon (PAC)–Si composite was investigated. To increase the pore size and surface area of the composite, ammonium bicarbonate (ABC) was introduced during high-energy ball-milling, ensuring a uniform distribution of silicon within the PAC matrix. The physical and structural properties of the developed material were evaluated using several advanced techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), and galvanostatic intermittent titration (GITT). Artificial graphite contains several macropores that can accommodate volume hysteresis and provide effective sites for anchoring Si nanoparticles, enabling efficient electrochemical reactions. GITT analysis revealed that the PAC-Si-CB-ABC composite exhibited superior lithium-ion diffusion compared to conventional graphite. The developed PAC(55%)-Si(45%)-CB-ABC electrode with PAA as the binder demonstrated a reversible capacity of 850 mAh g⁻¹ at 100 mA g⁻¹ and a high-rate capability of 600 mAh g⁻¹ at 2000 mA g⁻¹. A full cell employing the NCM622 cathode exhibited reversible cyclability of 128.9 mAh g⁻¹ with a reasonable energy density of 323.3 Wh kg⁻¹. These findings suggest that the developed composite is a useful anode system for advanced lithium-ion batteries.

The creation of effective supercapacitor materials is still a priority in the quest to improve energy storage technology. Herein, we present a novel nanocomposite composed of carbon nanoparticles (CNPs) and colloidal SnO₂ quantum dots (c-SQDs) or colloidal SnO₂ ultrasmall nanoparticles, synthesized through a facile sonochemical-assisted hydrothermal approach. The XRD and XPS analyses confirmed the successful synthesis and composition of the CNP/c-SQD nanocomposite. Morphology studies revealed a well-dispersed morphology with intimate interfacial interactions between the CNPs and c-SQDs. Specifically, the nanocomposite exhibited a high specific capacitance of 569 F/g at a current density of 1 A/g, surpassing conventional carbon-based supercapacitors. Furthermore, the nanocomposite displayed excellent stability with 99% capacity retention after 5000 cycles, indicative of its superior cyclability. These results underscore the potential of the CNP/c-SQD nanocomposite as a promising electrode material for high-performance supercapacitor applications, offering enhanced charge storage capacity, stability, and cyclability. This study contributes to the advancement of energy storage technologies, paving the way for the development of efficient and sustainable electrochemical energy storage devices.

Different concentrations (1, 3 and 5 wt%) of dysprosium (Dy³⁺)-doped ZnO/SnS (ZSD) nanophotocatalysts using the one-step facile hydrothermal method at 230 ℃ are presented. Their structure, morphological appearance, inclusion of constituent elements, bandgap engineering and luminescent nature are confirmed by the XRD, TEM, XPS, UV-DRS and PL techniques. The photocatalytic activity (PCA) of the prepared nano photocatalysts is studied in the presence of a model pollutant MB under solar light illumination. The degradation kinetics and charge separation mechanism of the ZSD photocatalysts are also presented. Our XRD analysis showed the mixed-phase occurrence of ZnO (hexagonal) and SnS (orthorhombic) from their JCPDS numbers with no additional traces of a doping element, which in turn indicates the purity, substantial crystal structure and high dispersion of the samples. TEM micrographs revealed the appearance of a flake structure and more agglomeration when increasing the dopant concentration. The XPS spectra confirmed the Zn²⁺, Sn²⁺, S²⁻, O²⁻ and Dy³⁺ oxidation states of the constituent elements along with carbon and nitrogen peaks. The Tauc plots showed a decreasing trend in the optical bandgap, i.e., a redshift due to the loading of Dy³⁺ ions into Sn²⁺ ions. The lower recombination rate of photoinduced e⁻-h⁺ pairs is noted when increasing the Dy³⁺ ion content; i.e., the luminescent intensity is suppressed when increasing the concentration of Dy³⁺ ions. The obtained degradation efficiency of the MB dye using the ZSD3 nano photocatalyst is around 98% for a duration of 120 min under solar light irradiation. The prepared ZSD photocatalyst follows pseudo first-order kinetics, and the evidence for attaining a robust Z-scheme PCA is presented in the form of the charge separation mechanism.

The demand for safer, sustainable, and economical energy storage devices has motivated the development of lithium dual-ion batteries (Li_DIBs) for large-scale storage applications. For the Li_DIBs, expanded graphite (EG) cathodes are valuable as anion intercalation host frameworks to fabricate safer and more cost-effective devices. In this study, three different carbon cathode materials, including microwave-treated expanded graphite (MW-EG), ball-milled expanded graphite (BM-EG), and high-temperature-carbonized carbon nanoflakes (CNFs), were developed by different synthesis methods. Li_DIBs were configured by employing 4 M of LiPF₆ in a dimethyl carbonate electrolyte and MW-EG/BM-EG/CNF as an anion host cathode. After 600 cycles, a Li-MW-EG Li_DIB exhibited a reversible capacity of 66.1 mAh/g with a high Coulombic efficiency of 96.2% at a current rate of 0.05 A/g and an outstanding average energy density of 298.97 Wh/kg (with an output voltage of 4.62 V). The remarkable electrochemical results are associated with (i) moderate structural defects with a very low I_D/I_G ratio (0.848), (ii) degree of graphitization, which improves the mechanical stability and conductivity, and (iii) large pore volume and pore diameter, easy facilitating the accumulation of PF₆⁻ ions. The energy density characteristics demonstrate the feasibility of utilizing MW-EG as a promising cathode for energy-related Li_DIB applications.