Developing a durable electrocatalyst with a high methanol oxidation reaction activity is highly important for anode design in direct methanol fuel cells. To that end, Pt-hematene sheets have been successfully synthesized by ultrasonic exfoliation followed by a double pulse deposition strategy to adjust the Pt loading. The morphology, structure, and composition of this new class of Pt decorated metal oxide nanosheet have been characterized by transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. Electrocatalytic characteristics have been systematically investigated by cyclic voltammetry and compared with commercial Pt/C catalyst. The novel Pt-hematene sheets exhibit a good mass activity with a low peak potential but most of all show an enhanced tolerance to the intermediates of methanol oxidation.

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Multi-walled carbon nanotubes (MWCNTs) directly grown on a stainless steel mesh were functionalized using a fast, solvent-free radiofrequency (RF) plasma technique. Two different gas mixtures of Ar/C2H6/O2 and Ar/C2H6/N2 were used to add oxygen- and nitrogen-containing functional groups to the surface of MWCNTs. The binder-free forest-like MWCNTs before and after functionalization were tested as supercapacitor electrodes. The structural and electrochemical characteristics of the electrodes were evaluated. The RF power (10-30 W) and functionalization time (1-20 min) were optimized to achieve the highest capacitance. Both nitrogen- and oxygen-functionalized MWCNTs showed improved capacitive behavior due to the presence of the functional groups on the MWCNT surface. The highest capacitance was obtained for the MWCNT electrode functionalized with the RF plasma employing the Ar/C2H6/O2 gas mixture at 20 W for 15 min, reaching the specific capacitance of 37.3 ± 1.1 mF cm-2 (196.3 ± 5.8 F g-1).