Sulfur-doped multi-walled carbon nanotubes (S-MWCNTs) derived from PEDOT-functionalized MWCNTs can significantly improve the dispersion of supported Pt nanoparticles and enhance their electrocatalytic performance for the MOR.

No abstract

Metal oxide-based nano/microstructures assembled on heteroatom-doped carbon nanomaterials are promising materials to design the electrocatalysts with enhanced electrochemical performances. In this work, a systematic protocol was contrived to fabricate hybrid electrode material based on Cu2O microspheres (MSs) supported on sulfur-doped multiwalled carbon nanotubes (Cu2O MSs/S-MWCNTs). The adequate doping of sulfur and successful fabrication of Cu2O MSs/S-MWCNTs were confirmed by various microscopic and spectroscopic techniques, and then the tailor-made Cu2O MSs/S-MWCNTs composite was employed to establish a nonenzymatic sensing system for controlled monitoring of glucose. A high surface area of Cu2O MSs and sulfur doping inside the MWCNTs collectively enhanced the electrocatalytic activity of Cu2O MSs/S-MWCNTs as revealed through cyclic voltammetry (CV) analysis. The enhanced electrochemical efficacy of Cu2O MSs/S-MWCNTs may be credited to the creation of heterojunctions during the doping process, forming the highly defected structures with increased number of catalytic active sites. In addition, the Cu2O MSs/S-MWCNTs/GCE presented the good amperometric response for glucose sensing attaining optimal linear range, satisfactory sensitivity, excellent stability, and glucose specific selectivity. These unique chemical and electrochemical features strongly encourage the potential applicability of our designed Cu2O MSs/S-MWCNT electrocatalyst for targeted monitoring of glucose.

Novel solid solutions of aluminum in tungsten carbide (WC) with or without carbon vacancies, which can be expressed by the chemical formula (W(0.5)Al(0.5))C(1-x) (x=0.0-0.5), have been synthesized by the solid-state reaction of W(0.5)Al(0.5) alloy and the proper amount of carbon at around 1673 K in vacuum. The reaction time decreases from 73 to 50 h on increasing the carbon vacancy concentration from 0 to 50 %. The formation of the intended products is certified, by X-ray diffraction, environmental scanning electron microscopy-energy-dispersive X-ray analysis, and inductively coupled plasma-atomic emission spectroscopy, even though the carbon vacancy concentration reaches the astonishing value of 50 %. The as-prepared (W(0.5)Al(0.5))C(1-x) samples have been identified as the hexagonal WC-type structure belonging to the space group P6m2 (Z=1). Moreover, the crystallographic results reveal that the substituting aluminum atoms in the WC are located in the 1a site (the W atom position of the WC structure) and the cell parameters decrease slightly with increasing vacancy concentration. The hardness of the (W(0.5)Al(0.5))C(1-x) system increases up to a maximum 2659 kg mm(-2) at a carbon vacancy concentration of about 35 %, and the density of (W(0.5)Al(0.5))C(1-x) is far lower than that of WC.