Graphite Plate Electrodes Research Articles

Scaling up Microbial Fuel Cells

The goal of this study was to quantify the relation between the surface area of the current-limiting electrode of a microbial fuel cell (MFC) and the power density generated by the MFC. Shewanella oneidensis (MR-1) was grown anaerobically in the anodic compartment of an MFC utilizing lactate as the electron donor. Graphite plate electrodes of various sizes were used as anodes. Commercially available air electrodes, composed of manganese-based catalyzed carbon bonded to a current-collecting screen made of platinum mesh, were used as cathodes, and dissolved oxygen was used as the cathodic reactant. The surface area of the cathode was always significantly larger than that of the anode, to ensure that the anode was the current-limiting electrode. The power density generated by the MFC decreased as the surface area of the anode increased, which fits well with the trend we detected comparing various published results. Thus, our findings bring into question the assertion that the overall power density generated by an MFC with large electrodes can be estimated by extrapolating from an electrode with a small surface area. Our results indicate that the maximum power density generated by an MFC is not directly proportional to the surface area of the anode, but is instead proportional to the logarithm of the surface area of the anode.

Cobalt modified solid superacid assisted electrochemical reaction of toluene with methanol

The electrochemical catalytic reaction of toluene with methanol, assisted with a pair of porous graphite plate electrodes, catalyzed by solid superacid of cobalt modification catalyst with chemical conversion higher than 81%, was described and investigated by UV–vis spectrum, scan electron microscopy (SEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and gas chromatography–mass spectrometry (GC–MS). A possible free radical reaction mechanism was proposed. It may be concluded that a simply and feasible electrochemical catalytic coupling oxidation reaction at room temperature and air pressure may be possible.

Horizontal semi-dry electroblotting for the detection of the low density lipoprotein receptor in solubilized liver membranes.

A high efficiency transfer of the low density lipoprotein (LDL) receptor proteins from polyacrylamide slab gel onto immobilizing nitrocellulose membranes using the horizontal semi-dry electrophoretic system is described. The transfer of the LDL receptors from solubilized rat liver microsomes was performed between two graphite plate electrodes in a continuous buffer system containing methanol and sodium dodecyl sulfate. The protein transfer was achieved in only 150 min at a constant current of 0.8 mA/cm2 at room temperature with very low Joule heat development. The homogeneous electric field yield between the two electrode plates produced a satisfactory transfer of the LDL-receptor protein band in spite of its high molecular weight, and only few protein traces remained in the polyacrylamide gel after blotting. This improved method allows a rapid and quantitative transfer of the LDL receptors without protein denaturation, since the specific binding activity of the blotted receptor is retained as demonstrated by ligand-blotting and immunoblotting.

Electro-oxidation of diarylacetylenes and diaryldiacetylenes

Diarylacetylenes led to 1,2-diaroyl-1,2-diarylethylenes and diaryldiacetylenes led to a mixture of acetylenic α-and γ-diketones, by anodic oxidation in MeCN–LiClO4 on a graphite plate electrode.

Electroblotting of multiple gels: a simple apparatus without buffer tank for rapid transfer of proteins from polycrylamide to nitrocellulose

A simple, horizontal device from rapid electorphoretic transfer of proteins from several polyacrylamide gels simultaneously is described. Up to six ‘TRANS-UNITS’ consisting of soaked filter paper on either side of polyacrylamide gel/nitrocellulose sheets that are separated dy dialysis membranes were stacked between graphite plate electrodes. The only buffer reservoir in the apparatus is that in stacked, soaked filter paper. A special buffer system based on the isotachophoresis theory was developed for this purpose. The electrophoretic transfer was performed with equal efficiency in all TRANS-UNITS of the stack. Only traces of a few proteins remained in the polycrylamide gel after transfer. With this apparatus, 50 protein bands from a human serum protein sample (diluted 1 : 100) were detected by immunoblotting with the retainment of the high resolution of the SDS-PAGE technique. The apparatus provided a constant current density of 0.8 mA/cm 2 during the 1-h tranfer time at 21°C, irrespective of the number of TRANS-UNITS. The apparatus generated 1–5 W in joule heat, depending on the number of TRANS-UNITS in the stack.