Wenxiu Yang

Bamboo-like carbon nanotube/Fe3C nanoparticle hybrids and their highly efficient catalysis for oxygen reduction.

The design of a new class of non-noble-metal catalysts with oxygen reduction reaction (ORR) activity superior to that of Pt is extremely important for future fuel cell devices. Here we demonstrate a one-pot, large-scale protocol for the controlled synthesis of new one-dimensional bamboo-like carbon nanotube/Fe(3)C nanoparticle hybrid nanoelectrocatalysts, which are directly prepared by annealing a mixture of PEG-PPG-PEG Pluronic P123, melamine, and Fe(NO(3))(3) at 800 °C in N(2). The resulting hybrid electrocatalysts show very high ORR activity with a half-wave potential of 0.861 V (vs reversible hydrogen electrode) in 0.10 M KOH solution, 49 mV more positive than that of 20 wt% Pt/C catalyst. Furthermore, they exhibit good ORR activity in acidic media, with an onset potential comparable to that of the Pt/C catalyst. Most importantly, they show much higher stability and better methanol tolerance, with almost no ORR polarization curve shift and no change of the oxygen reduction peak in the cyclic voltammogram in the presence of 1.0 M methanol, than those of the commercial Pt/C catalyst in both alkaline and acidic solutions. This makes them one of the best non-noble-metal catalysts ever reported for ORR in both alkaline and acidic solutions.

N,S-Codoped microporous carbon nanobelts with blooming nanoflowers for oxygen reduction

N,S-Codoped carbon nanobelts (NSCNBs) with blooming morning glory-like nanoflowers were developed by electrospinning. The NSCNBs exhibited higher oxygen reduction reaction activity and better stability than a commercial Pt/C catalyst in alkaline solution, and better stability than the Pt/C catalyst in acidic solution.

High performance of electrocatalytic oxidation and determination of hydrazine based on Pt nanoparticles/TiO2 nanosheets

In this work, highly dispersed Pt nanoparticles (PtNPs) were deposited on the surface of the TiO2 nanosheets (TiO2NSs) by the photodeposition method in the presence of methanol as holes scavengers. The results indicated that PtNPs were distributed on TiO2NSs successfully with the diameter of ca. 5-9 nm. The electrochemical experiments such as electrochemical impedance spectroscopy and cyclic voltammetry were used to study the electrochemical properties of the PtNPs/TiO2NSs modified glassy carbon electrode (GCE). The as-prepared PtNPs/TiO2NSs/GCE presents excellent electrocatalytic activity for hydrazine. The sensor can be used to determine hydrazine at low potential with a wide linear range, high sensitivity, and fast response time. Moreover, the sensor exhibits good selectivity and reproducibility. In addition, the recoveries were 100.1-105.3% for hydrazine in the tap water, indicating the PtNPs/TiO2NSs/GCE should be a promising sensor for the determination of hydrazine in real samples.