Tianxiang Zhou

N-Doped carbon nanorods as ultrasensitive electrochemical sensors for the determination of dopamine

Nitrogen-doped carbon nanorods (N-CNRs) are prepared by a direct carbonization method using polyaniline nanorods as the carbon precursor. The electrochemical behavior of the N-CNRs-Nafion modified electrode is evaluated in connection with dopamine and ascorbic acid by cyclic voltammetry and differential pulse voltammetry. Experimental results indicate that the N-CNRs modified electrode has improved current response and fast electron transfer kinetics. The linear response for the selective determination of dopamine in the presence of ascorbic acid is obtained in the range of 0.008 μM to 15.0 μM with a detection limit of 8.9 × 10−9 M (S/N = 3) by differential pulse voltammetry under optimum conditions. The N-CNRs-Nafion modified electrode exhibits a wide linear range, very low detection limit and anti-interference ability. Meanwhile, a kinetic reaction process and a reaction mechanism for the N-CNRs are also proposed.

Synthesis of ZnO@CNTs From Anhydrous Zinc Acetate via Thermal Decomposition

The ZnO@CNTs has been prepared via a thermal decomposition route. The spectra of X-ray powder diffraction (XRD) prove that as-prepared ZnO is primitive hexagonal phase and CNTs with an interlayer distance of 0.34 nm is low graphitized carbon in this research. The diameter and length of ZnO@CNTs are 150–200nm and 1.5–2µm, respectively. The vibration on 1625cm –1 , 1540cm –1 and 1380 cm –1 shows that the surface of ZnO@CNTs have great functional groups. Advance materials prepared via thermal decomposition techniques attract broad research interests [1-3]. In appropriate temperature and pressure, the size and structure of materials are controlled through the synthesis condition. Cha and co-workers have revealed that the thermal decomposition is economical and easy method to synthesis some monodispersed nanocrystal [3]. Metal oxide and carbon materials have been widely fabricated via thermal decomposition [2-9]. Carbon nanotubes (CNTs) with unique physical and chemical properties have broad applications in the field of many high-tech, especially assembled other nano-materials on the surface of CNTs to achieve the function of the CNTs. At the same time, ZnO has received widespread attention for its excellent performance in electronics, optics, photonics systems. So many scientists have considerable paid attention to assemble ZnO to carbon nanotubes to obtain excellent optics, catalyse, anti-bacterial properties. The ZnO@CNTs materials have been fabricated using many methods, such as electrostatic coordination approach [10], plasmaassisted sputtering technique [11], chemical vapor deposition[12,13] and so on. However, to the best of our knowledge, there is no report on the preparation of carbon nanotubes coating ZnO composite. In this study, the ZnO@CNTs has been prepared via thermal decomposition anhydrous zinc acetate without any catalyst and toxic reagents. The surface functional groups of CNTs have been investigated.