Huimin Wu

Synthesis of tremella-like CoS and its application in sensing of hydrogen peroxide and glucose

Different phases of cobalt sulfides have been fabricated by one-pot hydrothermal method. Comparing all of the prepared materials, and the results revealed that CoS was the most conductive and could accelerate electron transfer. The CoS presented tremella-like and excellent catalytic activities towards hydrogen peroxide and glucose. The sensor based on CoS performed amperometric sensing of hydrogen peroxide in a linear range between 5.00μM and 14.82mM. Meanwhile, sensing of glucose with double-linear range, one is between 5.00μM and 1.10mM, the other is between 1.20mM and 10.20mM. These due to the fact that more and more intermediate species absorb onto electrode surface with increasing the concentration of glucose, which limit the following glucose oxidation. Furthermore, the hydrogen peroxide and glucose sensors based on tremella-like CoS also exhibited excellent selectivity, stability, and reproducibility. Thus, the sensor showed potential utilities in hydrogen peroxide and glucose detection.

Electrochemical hydrogen peroxide sensor based on carbon supported Cu@Pt core-shell nanoparticles

The Cu@Pt/C nanocomposites have been synthesized via two-step reduction method. Electrochemical observations showed that the Cu@Pt/C had better electrocatalytic activity for the reduction of hydrogen peroxide than Pt/C, with a wide linear range between 0.50μM and 32.56mM, a high sensitivity of 351.3μAmM-1cm-2, and a low detection limit of 0.15μM (signal/noise=3). Furthermore, the sensor based on Cu@Pt/C has potential applications due to its excellent long-time stability, good reproducibility and acceptable selectivity.

Ultrasensitive electrochemical assay of hydrogen peroxide and glucose based on PtNi alloy decorated MWCNTs

A novel electrochemical assay based on PtNi/MWCNT nanocomposites was designed for ultrasensitive detection of hydrogen peroxide and glucose. The PtNi/MWCNT nanocomposites have been synthesized by a chemical reduction method and were investigated by X-ray diffraction, transmission electron microscopy, and electrochemical testing. The results demonstrated that the PtNi/MWCNT nanocomposites exhibited excellent electrocatalytic activity toward hydrogen peroxide and glucose. The electrocatalytic reduction of hydrogen peroxide showed a wide linear range from 0.2 μM to 24.6 mM, with a high sensitivity of 2123.1 μA mM−1 cm−2 and a detection limit of 60 nM (S/N = 3). At the same time, amperometric sensing of glucose was realized in a linear range from 0.1 μM to 9.0 mM, with an excellent sensitivity of 85 910.0 μA mM−1 cm−2. The present hybrid system also exhibited a good performance in terms of long-time stability, reproducibility and anti-interference ability.

Cocore-Ptshell nanoparticles as cathode catalyst for PEM fuel cells

Nanoscale Cocore–Ptshell particles were successfully synthesized based on a successive reduction strategy. The as-prepared core–shell nanoparticles were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, transmission electron microscope, and electrochemical methods. It was found that the catalytic reactivity of Cocore–Ptshell/C catalysts toward oxygen reduction was enhanced. It is believed that the prepared Cocore–Ptshell/C nanoparticles could be promising for cathode catalysis in proton exchange membrane fuel cells with much reduced Pt content, but significantly increased catalytic activity.

Electrochemical Determination of Uric Acid Using a Multiwalled Carbon Nanotube Platinum–Nickel Alloy Glassy Carbon Electrode

ABSTRACT Platinum–nickel nanoparticles were synthesized by a reduction procedure. The Pt–Ni/C composite was characterized by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, and electrochemical analysis. The measurements show that the Pt–Ni/multiwalled carbon nanotubes provided higher electrocatalytic activity for the oxidation of uric acid than Pt–Ni/carbon black. The sensor prepared from the characterized material provided a long linear dynamic range from 0.1 to 240.4 µM with a detection limit of 0.03 µM and a sensitivity of 41.21 µA mM−1 cm−2. The reported modified electrode also provided excellent selectivity, good stability, and satisfactory reproducibility for the determination of uric acid.

Effects of Different Carbon Matrix on the Pt0.55Co0.45 Catalysts Using for the Cathode of Proton Exchange Membrane Fuel Cell.

20 wt% Pt0.55Co0.45/C catalysts were prepared using a chemical reduction method, with Vulcan XC-72 conducting furnace black and double-walled carbon nanotubes (DWCNTs) as the carbon supports, respectively. The catalysts were compared with commercial BASF 20 wt% Pt/C (using Vulcan XC-72 carbon as support). The materials were characterized by X-ray diffraction and transmission electron microscopy (TEM). The electrochemical performance of the Pt/C and Pt0.55Co0.45/C catalysts was evaluated by cyclic voltammetry and steady-state measurements. Electrochemical measurements indicated that the Pt0.55Co0.45 nanocatalysts exhibited improved activity in the oxygen reduction reaction (ORR) on DWCNTs compared to those on Vulcan XC-72 carbon. It is suggested that DWCNTs will provide better catalysis support than Vulcan XC-72 carbon.