• Energy Research

We have effectively synthesized ZnS, FeSe2, and their nanocomposite using a straightforward and affordable solvothermal process. We also investigated for the first time their ideal electrochemical performance for supercapacitors. The ZnS and FeSe2 positive electrodes exhibit capacitances of 266.2 F g−1 and 294.3 F g−1, respectively, with fascinating nanostructures and morphology. Their respective nanocomposites, AZ-1, AZ-2, and AZ-3, deliver capacitances of 356.8, 444.4, and 326.1 F g−1 with significant rate performance in aqueous solution in a three-electrode assembly. The lowest ESR and Rct values of AZ-2 electrodes, which improved conductivity and charge transport kinetics and created a synergistic effect between ZnS and FeSe2 electrodes, are responsible for their exceptional capacitative performance. We built an asymmetric supercapacitor (AZ-2/AC) with an optimal voltage of 1.6 V, which demonstrated great power density (6250 W kg−1) and energy density (33 Wh kg−1) with remarkable cycling stability (88.1%) in an aqueous electrolyte after 12,000 cycles. As a result, FeSe2-based nanocomposites are strong contenders for realizing high energy and power delivery for practical applications.

Sodium-ion batteries (SIBs) can develop cost-effective and safe energy storage technology for substantial energy storage demands. In this work, we have developed manganese oxide (α-MnO2) nanorods for SIB applications. The crystal structure, which is crucial for high-performance energy storage, is examined systematically for the metal oxide cathode. The intercalation of sodium into the α-MnO2 matrix was studied using the theoretical density functional theory (DFT) studies. The DFT studies predict Na ions' facile diffusion kinetics through the MnO2 lattice with an attractively low diffusion barrier (0.21 eV). When employed as a cathode material for SIBs, MnO2 showed a moderate capacity (109 mAh·g-1 at C/20 current rate) and superior life cyclability (58.6% after 800 cycles) in NaPF6/EC+DMC (5% FEC) electrolyte. It shows a much higher capacity of 181 mAh·g-1 (C/20 current rate) in NaClO4/PC (5% FEC) electrolyte, though it suffers fast capacity fading (11.5% after 800 cycles). Our findings show that high crystallinity and hierarchical nanorod morphology of the MnO2 are responsible for better cycling performance in conjunction with fast and sustained charge-discharge behaviors.

In this study, a unique receiver design is given for consideration. The interior of the receiver is constructed out of aluminium, while the exterior is built of copper. The water that is held within the inner copper tube is heated by a system that circulates through it, and the hollow area that is found between the two tubes is filled with vegetable oil to decrease the amount of heat that is lost. As a direct consequence of this, low-pressure steam is generated. The efficiency of the system was evaluated in comparison to the performance of another receiver made up of the same number of tubes (aluminium). The receiver that was built with tubes made of different metals had an initial efficiency of 58.61%, whereas the receiver that was built with the same type of metal had an efficiency of just 36.5%. In conjunction with this study, integrated solar still found that due to Al-Al's introduction of this still interaction, the receiver of the parabolic trough collector has a lower efficiency. The still with the parabolic trough collector has a daily average efficiency of 52.25%, whereas the still without the collector has a daily average efficiency of 36.36%.

MXene/Ag2CrO4 nanocomposite was synthesized effectively by means of superficial low-cost co-precipitation technique in order to inspect its capacitive storage potential for supercapacitors. MXene was etched from MAX powder and Ag2CrO4 spinel was synthesized by an easy sol-gel scheme. X-Ray diffraction (XRD) revealed an addition in inter-planar spacing from 4.7 Å to 6.2 Å while Ag2CrO4 nanoparticles diffused in form of clusters over MXene layers that had been explored by scanning electron microscopy (SEM). Energy dispersive X-Ray (EDX) demonstrated the elemental analysis. Raman spectroscopy opens the gap between bonding structure of as-synthesized nanocomposite. From photoluminence (PL) spectra the energy band gap value 3.86 eV was estimated. Electrode properties were characterized by applying electrochemical observations such as cyclic voltammetry along with electrochemical impedance spectroscopy (EIS) for understanding redox mechanism and electron transfer rate constant Kapp. Additionally, this novel work will be an assessment to analyze the capacitive behavior of electrode in different electrolytes such as in acidic of 0.1 M H2SO4 has specific capacitance Csp = 525 F/g at 10 mVs−1 and much low value in basic of 1 M KOH electrolyte. This paper reflects the novel synthesis and applications of MXene/Ag2CrO4 nanocomposite electrode fabrication in energy storage devices such as supercapacitors.