Ternary molybdenum disulfide nanosheets-cobalt oxide nanocubes-platinum composite as efficient electrocatalyst for hydrogen evolution reaction

A high-performance ternary composite electrocatalyst, consisting of a molybdenum disulfide-cobalt oxide-platinum (Mo–Co–Pt) composite is synthesized by facile hydrothermal methods and then used as an electrocatalyst for hydrogen evolution reaction (HER). The ternary composite of Mo–Co–Pt is characterized using transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and linear sweep voltammetry. The as-synthesized Mo–Co–Pt-modified glassy carbon electrode shows better electrocatalytic performance than that of pure molybdenum disulfide (MoS2) nanosheets and cobalt oxide (Co3O4) nanocubes. Besides, the ternary composite electrode exhibits Pt-like performance along with the smallest Tafel slope and superior electrocatalytic stability in an acidic medium. Based on BET specific surface area and electrochemical impedance spectroscopy measurements, the MoS2 nanosheets and Pt nanoparticles enhance HER activity of the Co3O4 nanocubes in the ternary composite due to the synergistic effect between the two-dimensional structure and large surface area of MoS2 nanosheets and excellent electrocatalytic activity of the Pt nanoparticles. © 2020 Elsevier Lt

Molybdenum disulfide nanosheet decorated with silver nanoparticles for selective detection of dopamine

A metal-inorganic composite, comprises of silver-molybdenum disulfide nanosheets (Ag@MoS2) was synthesized at low temperature. The Ag@MoS2 composite was drop-casted onto a glassy carbon electrode (GCE) for a highly selective dopamine (DA) detection in the presence of interfering compounds such as uric acid (UA) and ascorbic acid (AA). The physicochemical analysis of the nanosheets was carried out with X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The as-prepared Ag@MoS2-modified GCE displayed excellent electrocatalytic activity toward DA oxidation, with a 0.2 μM detection limit at a signal-to-noise ratio of 3 and an extensive linear detection range from 1 μM to 500 μM (R2 = 0.9983). The fabricated non-enzymatic electrochemical sensor demonstrated superior selectivity and stability for the detection of DA with the removal of AA and UA interfering compounds

Nitrogen-doped graphene-supported zinc sulfide nanorods as efficient Pt-free for visible-light photocatalytic hydrogen production

Nitrogen-doped graphene-ZnS composite (NG-ZnS) was synthesized by thermal treatment of graphene-ZnS composite (G-ZnS) in NH3 medium. In the second step, the as-synthesized samples were deposited on indium tin oxide glass (ITO) by electrophoretic deposition for photocatalytic hydrogen evolution reaction. The as-prepared NG-ZnS-modified ITO electrode displayed excellent photocatalytic activity, rapid transient photocurrent response, superior stability and high recyclability compared to the pure ZnS and G-ZnS-modified ITO electrode due to the synergy between the photocatalytic activity of ZnS nanorods and the large surface area and high conductivity of N-graphene

Nitrogen-doped graphene-supported zinc sulfide nanorods as efficient Pt-free for visible-light photocatalytic hydrogen production

Nitrogen-doped graphene-ZnS composite (NG-ZnS) was synthesized by thermal treatment of graphene-ZnS composite (G-ZnS) in NH3 medium. In the second step, the as-synthesized samples were deposited on indium tin oxide glass (ITO) by electrophoretic deposition for photocatalytic hydrogen evolution reaction. The as-prepared NG-ZnS-modified ITO electrode displayed excellent photocatalytic activity, rapid transient photocurrent response, superior stability and high recyclability compared to the pure ZnS and G-ZnS-modified ITO electrode due to the synergy between the photocatalytic activity of ZnS nanorods and the large surface area and high conductivity of N-graphene

Synthesis and characterization of α-Fe2O3/polyaniline nanotube composite as electrochemical sensor for uric acid detection

We report the synthesis of α-Fe2O3/polyaniline nanotube (PAn NTs) composite as an electrochemical sensor for uric acid (UA) detection. Field emission scanning electron microscopy (FESEM) indicates a hexagonal shape of the α-Fe2O3 while a nanotube morphology of the PAn. Impedance spectroscopy results confirm a significant decrease in the charge transfer resistance of the glassy carbon electrode (GCE) modified with α-Fe2O3/PAn NTs due to the presence of PAn NTs. The results show that the increase in the conductivity of α-Fe2O3 in the presence of PAnNTs could improve the catalytic performance of α-Fe2O3/PAn NTs composite, compared to the pure α-Fe2O3 nanoparticles. From differential pulse voltammetry, a linear working range for the concentration of UA between 0.01 µM and 5 µM, with a LOD of 0.038 µM (S/N = 3) was obtained. The sensitivity of the linear segment is 0.433 μA µM−1. The reliability of the modified electrode towards the detection of UA was investigated in the presence of interfering acids such as ascorbic acid, citric acid and succinic acid

Large-scale hybrid silver nanowall-reduced graphene oxide biofilm: A novel morphology by facile electrochemical deposition

Increased attention has been focused on development of large-surface-area nanoengineered materials to enhance bone implants performance. Appropriate incorporations of functionalized carbon-based biofilms on the surface of artificial bone tissues can provide improved mechanobiological features. Besides, well-adhered potential coating interfaces corresponding wide spectrum antibacterial targets. Here, a novel morphology of hybrid silver (Ag) nanowall-green reduced graphene oxide (rGO) via facile methodology modified as-sputtered Ag grains to support Ti6Al7Nb implant (Ti67IMP) alloy. Layer-by-layer inorganic-organic topography obtained by physical vapor deposition magnetron sputtering (PVDMS) and subsequent one-step electrochemical deposition (ED) protocols. Microstructure, mechanical and wettability properties were characterized and cytocompatibility of designed composite-Ti67IMP system with human MG-63 osteosarcoma confirmed