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Electrode materials comprising SnO2 quantum dots embedded within ZnO hexagonal prisms were successfully synthesized for building cost-effective energy-storage devices. Extensive structural and functional characterizations were performed to assess the electrochemical performance of the electrodes. SEM–EDS results confirm a uniform distribution of SnO2 quantum dots across ZnO. The integration of SnO2 quantum dots with ZnO hexagonal prisms markedly improved the electrochemical behavior. The analysis of electrode functionality conducted in a 3 M KOH electrolyte revealed specific capacitances of 949.26 and 700.68 F g⁻1 for SnO2@ZnO and ZnO electrodes, respectively, under a current density of 2 A g⁻1. After undergoing 5,000 cycles at a current density of 15 A g⁻1, the SnO2@ZnO and ZnO electrodes displayed impressive cycling stability, maintaining specific capacitance retention rates of 89.9 and 92.2%, respectively. Additionally, a symmetric supercapacitor (SSC) device constructed using the SnO2@ZnO electrode showcased exceptional performance, exhibiting a specific capacitance of 83 F g⁻1 at 1.2 A g⁻1. Impressive power and energy densities were achieved by the device, with values reaching 2,808 and 70.2 W kg⁻1, respectively. Notably, the SnO2@ZnO SSC device maintained a capacity preservation of 75% throughout 5,000 galvanostatic charge–discharge sequences. The outcomes highlight the potential of SnO2@ZnO hexagonal prisms as candidates for energy-storage applications, offering scalability and cost-effectiveness. The proposed approach enhances the electrochemical performance while ensuring affordability, facilitating the creation of effective and financially feasible energy storage solutions.

Zinc-ion supercapacitors (ZISCs) exhibit great potential to store energy owing to the benefits of high power density and environmentally friendly features. However, solving the drawbacks of low specific energy and poor cyclic performance at high current rates is necessary. Thus, developing better cathode materials is a practical and efficient way to overcome these limitations. This work presents an encouraging design of two-dimensional (2D) graphite ultrathin nanosheets (GUNSs) as a cathode material for ZISCs. The experimental results show that the GUNSs-based cathode material exhibits a wide surface area and rapid charge transformation features. The 2D GUNS as a cathode was tested in three-electrode systems, and it provided an exceptionally high capacitance of 641 F/g at 1 A/g in an aqueous ZnSO4 electrolyte, better than GUNS-N2 (462 F/g at 1 A/g) and pristine graphite (225.8 F/g at 1 A/g). The 2D GUNS has a rate performance of 43.8% at a current density of 20 A/g, better than GUNS-N2 (35.6%) and pristine graphite (8.4%) at the same conditions. Furthermore, a ZISC device was fabricated using GUNSs as cathode and Zn-foil as anode with 1 M ZnSO4 electrolyte (denoted as GUNSs//Zn). The as-fabricated GUNSs//Zn device exhibits an excellent capacitance of 182.5 F/g at 1 A/g with good capacitance retention of 97.2%, which is better than pristine graphite (94.6%), and nitrogen-doped GUNS (GUNS-N2) cathode (95.7%). In addition, the GUNSs//Zn device demonstrated an ultrahigh cyclic life of 10,000 cycles, and 96.76% of capacitance was maintained. Furthermore, the GUNSs//Zn device delivers a specific energy of 64.88 W h/kg at an ultrahigh specific power of 802.67 W/kg and can run a light-emitting diode for practical applications.

The study utilized a simple and cost-effective approach to improve the photoelectrochemical (PEC) water-splitting performance of various materials, including reduced graphene oxide (rGO), tin oxide nanostructures (SnO2), and rGO/SnO2 composites. The composites examined were rS15, containing 15 mg of rGO and 45 mg of SnO2, and rS5, with 5 mg of rGO and 50 mg of SnO2, tested in a sodium hydroxide (NaOH) electrolyte. Notably, the rS5 electrode showed a significant increase in PEC efficiency in 0.1 M NaOH, achieving a peak photocurrent density of 13.24 mA cm−2 under illumination, which was seven times higher than that of pristine rGO nanostructures. This enhancement was attributed to the synergistic effects of the heterostructure, which reduced resistance and minimized charge recombination, thereby maximizing the catalytic activity across the various electrochemical applications. Furthermore, the rS5 anode demonstrated improved Tafel parameters, indicating faster reaction kinetics and lower overpotential for efficient current generation. These results highlight the potential for optimizing nanostructures to significantly enhance PEC performance, paving the way for advancements in sustainable water-splitting technologies. [ABSTRACT FROM AUTHOR]

This study presents a straightforward and cost-effective method to enhance the photoelectrochemical (PEC) water-splitting performance of α-Fe2O3 (F), SnO2 (S), and α-Fe2O3 decorated with SnO2 quantum dots (FS) photoanodes in a NaOH electrolyte. The FS electrode demonstrated a notable improvement in PEC efficiency within the electrolyte. In particular, the generated charges of the FS anode in the NaOH electrolyte reached approximately 12.01 mA cm−2 under illumination, indicating that the developed heterostructures effectively enhanced kinetics, leading to improved separation of induced carrier pairs. This active carrier-pair separation mechanism contributed considerably to the increased PEC activity in the 0.1 M NaOH electrolyte. The reduction in the bandgap of FS increased its absorption capability in visible light, which further enhanced the current density. Furthermore, the reduction in electrolyte resistance (9.71 Ω), internal resistance (20.19 Ω), charge transfer resistance (3.21 kΩ), Tafel slope (45.5 mV dec-1), limiting current density (−2.09 mA cm−2), and exchange current density (−3.68 mA cm−2) under illumination at the interface enhanced the charge density of FS. Further, a strong interaction among photoanode nanostructures significantly enhances PEC activity by improving efficient charge separation and transport, reducing recombination rates, and enabling quicker movement of charge carriers to the electrode/electrolyte interface. Thus, this study provides an effective approach to increasing the PEC activity of heterostructures. [ABSTRACT FROM AUTHOR]

This study employs a simple and cost-effective technique to enhance the photoelectrochemical (PEC) water-splitting performance of melamine cyanaurate microrods (M), SnO2 nanostructures (S), and melamine cyanaurate microrods decorated with SnO2 quantum dots (MS) by optimizing NaOH and Na2SO3 electrolytes. Notably, the MS electrode demonstrates a remarkable improvement in PEC efficiency in Na2SO3 solution associated with NaOH solution. Specifically, the induced currents of the MS anode in the Na2SO3 electrolyte are approximately 6.28 mAcm−2 more than those observed in the NaOH electrolyte solution. It is revealed that SO 3 2 − anions effectively consume the holes, leading to improved separation of the generated charge pairs. This effective charge separation mechanism significantly contributes to the enhanced PEC performance observed in Na2SO3 electrolytes. The findings of this study suggest a capable approach for improving the PEC activity of the materials through the careful optimization of the supported electrolytes. [ABSTRACT FROM AUTHOR]

The rational design of low-cost electrode materials with superior redox activity and high electrochemical conductivity has attracted extensive interest for next-generation supercapacitors. In this study, SnO2 quantum dot–decorated BiOI nanoflowers (BIOS) were successfully synthesized for application in high-capacity supercapacitors. Various structural, morphological, and electrochemical studies were performed on the synthesized samples. The SnO2 quantum dots (SO) decorated over the BiOI nanostructures exhibited superior electrochemical behavior compared to pure BiOI nanostructures (BIO). The electrochemical performance of the fabricated electrodes was investigated in 3.0 M KOH electrolyte. The BIOS electrode demonstrated an excellent specific capacity of 1285 F.g−1 at a current density of 11 A·g−1, 7.5 times that of the BIO electrode. The increased availability of active sites for ion transfer in possible oxidation/reduction reactions after the decoration of SO over BIO nanostructures may have enhanced the galvanostatic charge–discharge (GCD) characteristics. Despite 3000 GCD cycles, the BIOS electrode still attained better supercapacitive characteristics than the BIO electrode. The findings of this study may assist in designing advanced, cost-effective, and high-performance electrode materials for energy storage applications. [ABSTRACT FROM AUTHOR]

Heterostructures have recently been used to generate stable photo-induced currents via photoelectrochemical (PEC) activity. However, the effect of electrolytes on charge-transfer kinetics and the generation of photo-induced currents on heterostructures are major challenges in PEC. The effect of the electrolyte on the synthesized photoelectrodes is demonstrated in this study under various conditions using electrochemical impedance spectroscopy, linear sweep voltammetry, chronoamperometry, and Tafel analyses. The lowest transfer kinetics resistance and highest photocurrent densities are achieved in 0.1 M KOH when compared to those in 0.1 M Na2SO4 aqueous electrolytes. Furthermore, various applied voltage effects on the generation of currents have been studied for the synthesized electrodes at a voltage of +0.5 V in both electrolytes. The maximum induced-current achieved was 1.39 mA cm−2 for BW-SO, under illumination in the 0.1 M KOH electrolyte. The BW-SO heterostructure presented enhanced performance due to improved light absorption capability, the lowest resistance values, and the synergistic effect of the heterostructures. [ABSTRACT FROM AUTHOR]

Summary: A NASICON‐type LiZr2(PO4)3 (LZP) and Li1.2Al0.2Zr1.8(PO4)3 (LAZP) anode materials are synthesized via a facile method, materials were characterized by a variety of structural techniques, investigated the electrochemical performance for rechargeable battery applications. A highly stable rhombohedral phase of LAZP is noticed at room temperature, with a discharge capacity of 909 mAh.g−1, which is 1.6 times higher than that of LZP. Further, the highly stable charge storage performance is observed up to 3000 cycles with a Coulombic efficiency of 99%. For the first time, we investigated the in‐situ temperature effect on the discharge capacity of the assembled anode material, found a strong effect on the discharge capacity, and achieved ~120 and 149 mAh.g−1 at 65°C for LZP and LAZP anodes. Furthermore, the real‐time charge holding effect of LAZP cell is performed with the computer, the cell worked well in the CMOS battery slot without a CMOS battery error during CPU turn‐on condition for 1536 h. In brief, an optimized electrode material of LAZP showed greater stability and capacity with high efficiency compared with LZP even at elevated temperatures. Hence, LAZP may be utilized to fabricate a coin cell for real time applications. [ABSTRACT FROM AUTHOR]