Biomedical subjects

Sheng-pei Chen

Publications and source records attributed to Sheng-pei Chen.

3 recordsLinked to original sources

PubMed2006

[EQCM and in situ FTIR studies on the adsorption and oxidation of 1-butanol at a platinum electrode in alkaline media].

The adsorption and oxidation of 1-butanol in alkaline media on a platinum electrode were investigated mainly by EQCM and in situ FTIR spectroscopy. The experimental results demonstrate that the electrooxidation of 1-butanol is closely relative to solution acidity. Since no chemically adsorbed species, such as CO, were evidenced by in situ FTIR spectroscopy, the adsorption of 1-butanol or its dissociative products on Pt surface is suggested by EQCM and CV data. Only one current peak of 1-butanol oxidation in PGPS was detected at -0.23 V/SCE, which illustrated the disappearance of the second current peak due to Pt electrode passivation in alkaline media. The final product of 1-butanol oxidation is only butyric acid anion under experimental condition. It may therefore be suggested that the main reaction occurring at the electrode is the oxidation of 1-butanol to butyric acid anion. The EQCM studies provide quantitative results of surface mass variation and have shed light on elucidating 1-butanol oxidation.

English Abstract↗

PubMed2004

[Solid/liquid interfacial in situ IR microscope and step-scan time-resolved FTIR spectroscopy and applications in studies of nanomaterials].

Electrochemical in situ microscope IR reflection spectroscopy and step-scan time-resolved FTIR reflection spectroscopy were established by using an IR-plan advantage microscope and a Nexus 870 FTIR instrument, and a home-made signal synchronizer that harmonizes electrode polarization potential and step-scan spectral data collection sequence. These new techniques have been applied in studies of particular IR properties of 2-dimensional nanomaterials. By applying a treatment of fast potential cycling with different time (tau), a set of nanostructured Pt microelectrodes were prepared. CO adsorption was employed as a probe reaction together with in situ developed microscope FTIR spectroscopy. The results illustrated the variation of abnormal IR features with the nanostructure and the thickness (i.e., the size) of film formed on Pt microelectrode, i.e., following the increase of tau in fast potential cycling treatment, the direction of CO band was turned from absorption to antiabsorption direction, and the intensity and the width of CO band were increased. By taking the advantage of the abnormal infrared effects of nanostructured Pt microelectrode, the sensitivity of in situ IR reflection spectroscopy has been significantly improved, and spectra of time-resolution as fast as 50 micros have been recorded at solid/liquid interfaces. The current studies demonstrated not only the success of development of new techniques of in situ IR spectroscopy, but also the exploitation of the established techniques in studies of nanomaterials.

English Abstract↗

PubMed2003

[In situ FTIR spectroscopy studies of HCOOH oxidation on surface alloy electrocatalysts].

Electrocatalytic properties of three electrodes for formic acid oxidation were studied by using electrochemical in situ FTIR spectroscopy and cyclic voltammetry in this paper. It is demonstrated that the electrocatalytical mechanism of formic acid oxidation on platinum-dispersed carbon(Pt/GC) is similar to that on massive platinum, which involves two paths, i.e. one way through active intermediate and the other through poison intermediate to CO2. The Pt/GC exhibits higher catalytivity than pure platinum. The electrode of Pt/GC modified by Sb (Sb-Pt/GC) was also prepared in the work. It was observed that the onset potential (Ei) for formic acid oxidation on Sb-Pt/GC was shift negatively for 0.20 V. The peak potential (Ep) was observed to shifted negatively to 0.34 V and the value of oxidation current (jp) was enhanced nearly 7.28 times. Similar results were also observed on surface alloy/GC prepared. In this case, Ei and Ep were -0.12 and 0.32 V, respectively, jp was enhanced about 8.15 times, and FWHM (full width at half maximum) was 0.50 V. It is indicated that Sb-Pt/GC and surface alloy/GC can not only effectively restrain the formation of poison intermediate CO, but also significantly increase the electrocatalytic activities for oxidation of active intermediates.

Adsorption↗