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Few-layer two-dimensional (2D) molybdenum disulfide (MoS2) has great potential in designing high-performance supercapacitors due to its high theoretical specific capacity, tunable bandgap, and fascinating 2D layered structure. However, the lack of efficient synthesis methods, cost-effectiveness, and mass production of few-layered MoS2 hindered its practical applications. Moreover, a large gap between theoretical specific capacitance and the experiment comes from the traditional manufacturing approaches involving polymer binders to prepare the electrode for electrochemical testing. We report an accessible and efficient approach to liquid-phase exfoliation of bulk MoS2 into high-quality, few-layered MoS2 using the green method. We have constructed few layered MoS2 on a Ni-foam as an electrode for electrochemical analysis without any polymer binder or black carbon, which exhibits significant improvements in supercapacitor performance compared to the bulk. The highest specific capacitance achieved is 985 F g−1 at 8 A g−1. The 2D layered structure provides stable channels that facilitate K+ intercalation/desorption during charging and discharging processes, helping to prevent the deposition and accumulation of ions. Finally, theoretical calculations were performed to calculate the electronic structure, adsorption energy, diffusion barrier, and charge transfer of K intercalated and adsorbed bulk and monolayer 2H-MoS2, respectively. The calculated migration energy of the K atom diffusion on monolayer MoS2 (0.05 eV) is considerably lower than that of the bulk (0.8 eV), demonstrating a significant enhancement in electrochemical performance with reducing layer thickness. [ABSTRACT FROM AUTHOR]

Nickel–cobalt hydroxide thin films were synthesized using the chemical bath deposition method, and the effect of thermal annealing (373–673 K) on their physicochemical and electrochemical characteristics was explored. The X-ray diffraction study showed a cubic crystalline structure of NiCo2O4 electrode formed above annealing temperature of 573 K. Field emission scanning electron spectroscopy (FE-SEM) study revealed that after annealing, NiCo2O4 electrode showed urchin-like microspheres morphology with superhydrophilic nature. The electrode annealed at 573 K exhibited outstanding electrochemical performance with a specific capacitance of 470 F g−1 at 0.4 A g−1 current density. Over 2000 cycles, electrode demonstrated capacitive retention of 75.55%. Finally, NiCo2O4 and Fe2O3 thin films were used to construct the asymmetric supercapacitor (ASC) device. The ASC device manifested energy density of 40 Wh kg−1 at power density of 1.66 kW kg−1 and 82% retention after 2000 CV cycles. [ABSTRACT FROM AUTHOR]

We present a simplistic, ultrafast, and facile hydrothermal deposition of ternary Cu2SnS3 nanoparticles (CTS NPs). The fabricated CTS NPs show superior antimicrobial and photocatalytic activities. In the presence of UV-Visible illumination, methylene blue (MB) dye was studied for photocatalytic dye degradation activity of CTS NPs. Excellent efficiency is shown by incorporating CTS NPs to degrade MB dye. There is a ~95% decrease in the absorbance peak of the dye solution within 120 min. Similarly, CTS NPs tested against three bacterial strains, i.e., B. subtilis, S. aureus, P. vulgaris, and one fungal strain C. albicans, defining the lowest inhibitory concentration and zone of inhibition, revealed greater antimicrobial activity. Hence, it is concluded that the CTS NPs are photocatalytically and antimicrobially active and have potential in biomedicine. [ABSTRACT FROM AUTHOR]