PdSn nanocatalysts supported on carbon nanotubes synthesized in deep eutectic solvents with high activity for formic acid electrooxidation

A novel strategy in DESs for the fabrication of MWCNTs-supported PdSn alloy nanostructures is reported. The prepared PdSn/MWCNT shows remarkably improved electrocatalytic performance towards formic acid oxidation reaction.

Galvanic replacement of electrodeposited nickel by palladium and investigation of the electrocatalytic activity of synthesized Pd/(Ni) for hydrogen evolution and formic acid oxidation

Highly active Pd/(Ni) catalysts were synthesized by well controlled galvanic replacement of electrodeposited nickel, towards hydrogen evolution and FA oxidation.

Electrodeposition of triangular Pd rod nanostructures and their electrocatalytic and SERS activities

We report a simple one-step electrodeposition of triangular Pd rod nanostructures on clean Au substrates without additives. Scanning electron microscopy, transmission electron microscopy, and electrochemical techniques were utilized to characterize the structural features of the triangular Pd rod nanostructures. The regulation of the electrodeposition rate by optimizing the electrolyte concentration and applied potential was critical for the anisotropic growth of Pd in the vertical direction. The triangular Pd rod structures exhibited electrocatalytic activities for oxygen reduction and methanol oxidation reactions. These surfaces could be effectively utilized as reproducible surface-enhanced Raman scattering (SERS) active substrates to produce stable SERS signals under electrochemical systems. A simple preparation of well-defined triangular Pd rod structures would allow new opportunities in various areas utilizing Pd-based nanostructured surfaces.

Enhanced photoelectrocatalytic performance of titanium dioxide/carbon cloth based photoelectrodes by graphene modification under visible-light irradiation

Reduced graphene oxide nanosheets modified TiO2 nanospheres on carbon cloth electrodes (RGO/TiO2/CC) have been fabricated and used for photoelectrocatalytic (PEC) degradation of organic pollutants under visible light irradiation. The fabricated RGO/TiO2/CC electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy. Compared with TiO2/CC electrode, the RGO modified TiO2/CC electrode evidently shows improved visible light-driven PEC activity for degradation of an often used model pollutant, methylene blue (MB). Moreover, the efficiency of MB degradation by PEC process (0.0133 min(-1)) is about 13-fold and 7-fold faster than that of electrochemical process (0.001 min(-1)) and photocatalytic process (0.0018 min(-1)), respectively. The improved catalytic activity for PEC degradation of MB pollutants could be attributed to the existence of RGO, which extends the absorption onset of TiO2 to longer wavelength direction and promotes the separation of electron-hole pairs generated under visible light irradiation. The promotion effect on the electron-hole separation is supported by photocurrent and electrochemical impedance measurements. In addition, a synergetic effect of photocatalysis and electrocatalysis is involved in the PEC process, by which the recombination of photogenerated electron-hole pairs is significantly suppressed.

Fabrication of noble-metal catalysts with a desired surface wettability and their applications in deciphering multiphase reactions

Noble-metal Pd and Pt catalysts with a wide range of surface wettability were fabricated through an electrochemical approach and were characterized with scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and atomic force microscopy. The importance of surface wettability of solid catalysts in multiphase reactions-especially their correlation to the nature of the studied chemical system-was investigated by reducing oxygen in an alkaline solution and oxidizing hydrogen peroxide and sodium formate in alkaline or buffered solutions at the as-prepared catalysts. These experiments illustrate that the nature of a multiphase reaction plays a critical role in determining the influence of surface wettability on the catalyst performance, providing a unique approach to decipher the reaction process. The investigation allows us to gain new insights into the electrochemical oxidation of sodium formate.