The electrochemistry of horse heart cytochrome c was studied by cyclic voltammetry at a glassy carbon electrode modified with single-wall carbon nanotubes (SWNTs). A pair of well-defined redox waves was obtained in cytochrome c aqueous solution at an activated SWNT film-modified electrode. The optimal conditions for activating the SWNT film-modified electrode has been determined. The electrode reaction of cytochrome c is a diffusion-controlled process. The peak current increases linearly with the concentration of cytochrome c in the range from 3.0 x 10(-5)-7.0 x 10(-4) M. The detection limit is 1.0 x 10(-5) M. The activated SWNT film was characterized by scanning electron microscopy. Furthermore, interaction of cytochrome c with adenine was characterized by electrochemical and spectral methods.

Ultrasmall molybdenum sulfide nanoparticles with diameters of 1.47 AE 0.16 nm were fabricated from bulk MoS 2 by a combination of ultrasonication and centrifugation. The nanoparticles were then assembled on an Au surface to form a film with high electrocatalytic activity for hydrogen evolution reaction (HER). A Tafel slope of 69 mV per decade was measured for this film and the onset potential was estimated to be À0.09 V. The small loading (1.03 mg cm À2 ) and the high current density (0.92 mA cm À2 at h ¼ 0.15 V) demonstrated extremely high catalytic efficiency. X-ray photoelectron spectroscopic results revealed that the assembled nanoparticle film was sulfur enriched with abundant S edges and a structural rearrangement of the S rich particles might occur during the self-assembly process, resulting in significantly enhanced electrocatalytic activity for HER. Electrochemical impedance measurements suggested that the assembling process optimized the conductivity of the nanoparticle film, which contributed to the enhanced HER catalytic activity. Our research has provided a new way to synthesize active molybdenum sulfide nanoparticles for HER and a new approach to achieve enrichment of S edges on molybdenum sulfide, which might have potential use not only for electrocatalytic HER, but also for photoelectrocatalytic HER and plasmon-enhanced water splitting. Broader contextHydrogen produced by the water splitting process could potentially address the needs for the sustainable production of fuels in a manner that is renewable and carbon-free. However, cheap catalysts are required to overcome the large overpotential for hydrogen evolution reaction (HER) in an affordable manner. Recent studies have shown that sulfur edges of MoS 2 are quite active for HER. As a result, much effort has been focused on trying to acquire MoS 2 or MoS x nanomaterials with a plethora of sulfur edges. Here, we demonstrate a novel approach for synthesizing monodispersed molybdenum sulde nanoparticles with ultrasmall diameters and a new strategy for achieving enrichment of active S edges on molybdenum suldes by exploiting the covalent bonding of the nanocatalysts with the underlying gold electrode. The work is benecial not only for the design of highly efficient molybdenum sulde based HER catalysts but also for the synthesis of new catalysts for photoelectrocatalytic HER and plasmon-enhanced water splitting.

Reduced graphene oxide/platinum supported electrocatalysts (Pt/RGO) were synthesized by employing a fast and eco-friendly microwave-assisted polyol process, which facilitated the simultaneous reduction of graphene oxide and formation of Pt nanocrystals. This system was tested for potential use as an anode material through the electrooxidation of methanol. Compared to the commercial carbon-supported Pt electrocatalysts, the Pt/ RGO showed an unprecedented CO poisoning tolerance, high electrochemical active surface area, and high catalytic mass activity for methanol oxidation reaction, demonstrated by increases of 110, 134, and 60%, respectively. We found that the high concentration of oxygen functional groups on reduced graphene oxide plays a major role on the removal of carbonaceous species on the adjacent Pt sites, underlining a synergetic effect between the oxygen moieties on graphene support and Pt nanoparticles. The present microwave assisted synthesis of Pt/RGO provides a new path to prepare electrocatalysts with excellent electrocatalytic activity and CO tolerance, which is of great significance in energy-related applications.