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Increasing concerns about the vulnerability of the world's energy supply and the necessity to implement sustainable technologies have prompted researchers to develop high-performance electrocatalysts that are affordable and efficient for converting and storing renewable energy. This article reports a facile approach to fabricating two-dimensional (2D) Ge-decorated h-BN/MoS2 heterostructure nanosheets by self-assembly for multiple electrochemical applications such as supercapacitor and hydrogen evolution reactions. The organization of the physical and chemical links between the germanium modulations on the heterostructure of boron nitride/molybdenum sulphide (Ge/h-BN/MoS2) were facilitated to generate more active sites. Furthermore, the asymmetric supercapacitor of Ge-decorated h-BN/MoS2 amplified the capacitance to 558.53 F g−1 at 1 A g−1 current density and 159.19 F g−1 at 10 A g−1, in addition to a retention rate of 85.69% after 2000 cycles. Moreover, the Ge-decorated h-BN/MoS2 catalyst realized a low over-potential value, with an RHE of 0.57 (HER) at 5 mA/cm2, a Tafel value of ∼204 mV/dec, and long-term electrolysis stability of 10 h. This work may open the door for further investigations on metal-decorated heterostructures, which have a significant potential for both supercapacitor and water-splitting applications. [ABSTRACT FROM AUTHOR]

The morphological evolution of ZnO nanostructures grown under various argon sputtering pressures and substrate temperatures has been systematically investigated. A surface phase diagram depicting compact two-dimensional thin films to various types of one-dimensional structures as a function of pressure and temperature is constructed. Structural studies of ZnO nanostructures reveal the preferential orientation along the -axis of a hexagonal wurtzite crystal structure with a highly crystalline nature. However, the c as-grown ZnO nanostructures slightly experience compressive strain, which increases with the argon sputtering pressure. Exciton recombination and point defects have been extensively analyzed by temperature-dependent photoluminescence spectroscopy. The observation of donor-bound exciton emission and its replicas reveals the high optical quality of the nanostructures. Nevertheless, the observed visible emission indicates the presence of point defects which significantly depend on the deposition pressure. The characteristic visible emission bands at 2.28 and 2.02 eV provide strong evidence for the existence of oxygen vacancies and interstitial sites in ZnO nanostructures irrespective of growth temperature and pressure. [ABSTRACT FROM AUTHOR]

In the present study, a chemical precipitation method is adopted to synthesize bismuth vanadate nanoparticles. The calcination temperature dependent photocatalytic and antibacterial activities of BiVO 4 nanoparticles are examined. The structural analysis evidences the monoclinic phase of BiVO 4 nanoparticles, where the grain size increases with calcination temperature. Interestingly, BiVO 4 nanoparticles calcined at 400 °C exhibit superior photocatalytic behaviour against methylene blue dye ( K = 0.02169 min -1 ) under natural solar irradiation, which exhibits good stability for up to three cycles. The evolution of antibacterial activity studies using a well diffusion assay suggest that the BiVO 4 nanoparticles calcined at 400 °C can act as an effective growth inhibitor of pathogenic Gram-negative ( P. aeruginosa & A. baumannii ) and Gram-positive bacteria ( S. aureus )., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)