Sacrificial-template-free synthesis of core-shell C@Bi2S3 heterostructures for efficient supercapacitor and H-2 production applications

Core-shell heterostructures have attracted considerable attention owing to their unique properties and broad range of applications in lithium ion batteries, supercapacitors, and catalysis. Conversely, the effective synthesis of Bi2S3 nanorod core@ amorphous carbon shell heterostructure remains an important challenge. In this study, C@Bi2S3 core-shell heterostructures with enhanced supercapacitor performance were synthesized via sacrificial-template-free one-pot-synthesis method. The highest specific capacities of the C@Bi2S3 core shell was 333.43 F g(-1) at a current density of 1 A g(-1). Core-shell-structured C@Bi2S3 exhibits 1.86 times higher photocatalytic H-2 production than the pristine Bi2S3 under simulated solar light irradiation. This core-shell feature of C@Bi2S3 provides efficient charge separation and transfer owing to the formed heterojunction and a short radial transfer path, thus efficiently diminishing the charge recombination; it also facilitates plenty of active sites for the hydrogen evolution reaction owing to its mesoporous nature. These outcomes will open opportunities for developing low-cost and noble-metal-free efficient electrode materials for water splitting and supercapacitor applications

Influence of calcination temperature on Cd0.3Co0.7Fe2O4 nanoparticles: Structural, thermal and magnetic properties

Cadmium substituted cobalt ferrite nanoparticles are synthesis using the chemical method. The as-prepared ferrite nanoparticles are calcinated at 300 °C and 600 °C respectively. The samples are studied using; Powder XRD, SEM with EDX, TEM, FT-IR, TG-DTA and vibrating sample magnetometer (VSM) in order to study the calcination temperature effect on structural, morphological and magnetic properties. The magnetic properties, like saturation magnetization and coercivity increases with increasing the calcination temperature. This enhancement is attributed to the transition from amulti-domain to a single-domain nature. The absorption bands observed at 588 cm-1 (ν<inf>1</inf>) and 440 cm-1 (ν<inf>2</inf>) are attributed to the vibrations of tetrahedral and octahedral complexes. The TG-DTA curves reveal the thermal stability of the prepared ferrite nanoparticles. The calcination temperature influences the magnetic properties, surface morphology and crystalline size. © 2015 Elsevier B.V. All rights reserved.

Synthesis, characterization, and optical properties of visible light-driven Bi2S3 nanorod photocatalysts

We report a simple and large-scale one-pot method for the synthesis of Bi2S3 nanorods by using the complexation of Bi(NO3)3??5H2O and Na2S??9H2O precursors. The as-synthesized photocatalyst was characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, high-resolution X-ray photoelectron spectroscopy, UV-vis spectroscopy, N2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric and differential thermal analysis measurements. The photocatalytic performance of the Bi2S3 nanorods was evaluated for the photodegradation of phenol red under visible light irradiation. The orthorhombic Bi2S3 photocatalyst exhibited a 99% photocatalytic efficiency at 100 min under visible light irradiation, which is ascribed to the high specific surface area and crystallinity. The active sites on the Bi2S3 photocatalyst diminished the unwanted recombination of charge carriers within the photocatalyst

Synthesis of vanadium-pentoxide-supported graphitic carbon nitride heterostructure and studied their hydrogen evolution activity under solar light

Noble-metal-free co-catalyst supported with a highly active and stable photocatalyst is of considerable importance to realize low cost and scaled up photocatalytic hydrogen evolution. An inorganic-organic two-dimensional (2D)/one-dimensional (1D) graphitic carbon nitride (g-C3N4) nanosheet anchored with a vanadium pentoxide (V2O5) nanoparticle heterojunction photocatalyst (GCN/V2O5-3) with excellent solar-light-driven photocatalytic performance was prepared using a facilethermal decomposition method and used for photocatalytic hydrogen (H-2) evolution from concentrated lactic acid aqueous solution. The optimized GCN/V2O5-3 catalyst attained a high initial H-2 evolution rate of 2891.53 mu molg(-1), which is 2.44 times greater than that of pristine g-C3N4 under simulated solar light irradiation. In addition, the GCN/V2O5-3 catalyst is relatively stable for 5h H-2 evolution reactions, indicating the robustness of the V2O5 co-catalyst. The improved photocatalytic activity of the g-C3N4/V2O5 composites can be ascribed to their large specific surface area. Photoelectrochemical analysis results clearly show that V2O5 co-catalyst captures photoinducedholes from the valance band of the excited g-C3N4 by a Z-scheme mechanism and thusimproving the charge separation performance andendorse the H+ reduction to H-2. Lastly, the mechanism of photocatalytic H-2 evolution of the g-C3N4/V2O5 composite is discussed. Importantly, because of its high stability, easy processing, and low cost, the V2O5 co-catalyst has abundant potential in designing high-performance-semiconductor/organic photocatalysts for large-scale H-2 production utilizing renewable energy sources