The Effect of TiO2 on the Catalytic Activity of a PtRu/C Catalyst for Methanol Oxidation

Carbon-Coated and Interfacial-Functionalized Mixed-Phase Mox Ti1-x O2-δ Nanotubes as Highly Active and Durable PtRu Catalyst Support for Methanol Electrooxidation

A synchronous carbon-coating and interfacial-functionalizing approach is proposed for the fabrication of Mo-doped Mo_x Ti_1-x O_2-δ nanotubes (C@IF-MTNTs) under mild hydrothermal reaction with subsequent annealing as advanced catalyst supports for PtRu nanoparticles (NPs) towards methanol electrooxidation. The carbonation of glucose and Mo-doping takes place simultaneously at the interface of pristine anatase TiO₂ nanotubes (TNTs), generating a unique concentric multilayered one-dimensional (1D) structure with crystalline an anatase/rutile mixed-phase TiO₂ core and Mo-functionalized interface and subsequently a carbon shell. The obtained PtRu/C@IF-MTNTs catalyst exhibits an over 2 times higher mass activity with comparable durability than that of the unmodified PtRu/C@TNTs catalyst and over 1.7 times higher mass activity with over 20 % higher stability than that of PtRu/C catalyst. Such superior catalytic performance towards methanol electrooxidation is ascribed to the Mo-functionalized interface, concentric multilayered 1D architecture, and anatase/rutile mixed-phase core, which facilitates the charge transport through 1D structural support and electronic interaction between C@IF-MTNTs and ultrafine PtRu NPs. This work reveals the critical application of a 1D interfacial functionalized architecture for advanced energy storage and conversion.

A novel electrochemical sensor based on Cu@Ni/MWCNTs nanocomposite for simultaneous determination of guanine and adenine

A novel electrochemical sensing platform based on combination of multi-walled carbon nanotubes and copper-nickel hybrid nanoparticles (Cu@Ni/MWCNTs) was developed for simultaneous detection of guanine (G) and adenine (A). The Ni/MWCNTs and Cu@Ni/MWCNTs nanocomposites were characterized by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). The electrochemical behaviors of G and A on the modified electrode were explored by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in phosphate buffer with pH 3.0. Under the optimal conditions, electrical signals were linear over the concentration ranges from 5.0 to 180μM and 8.0 to 150μM for simultaneous determination G and A with the detection limit as low as 0.35μM and 0.56μM (S/N = 3), respectively. Furthermore, linear concentration ranges in individual determination are 1.0-180μM and 2.0-150μM with detection limits of 0.17μM and 0.33μM (S/N = 3) for G and A, respectively. The sensor was successfully used to quantify G and A in real samples. The Cu@Ni/MWCNTs composite presented here can serve as a promising candidate for developing electrochemical sensor devices and plays an important role in widespread fields.