Controllable synthesis of BiPr composite oxide nanowires electrocatalyst for sensitive L-cysteine sensing properties

Abstract

BiPr composite oxide nanowires with rhombodedral Bi1.35Pr0.65O3, monoclinic Bi2O3 and monoclinic Pr5O9 phases were synthesized via a facile sodium dodecyl sulfate (SDS) assisted hydrothermal route. The obtained nanowires were characterized by X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements. The BiPr composite oxide nanowires possess poly-crystalline structure, semi-circular tips, diameter and length of 20-100 nm and several micrometers, respectively. SDS is essential for the formation of the BiPr composite oxide nanowires which can be explained by a SDS assisted hydrothermal growth process. Electrochemical impedance spectroscopy (EIS) shows that the electrons are easier to transfer by the surface of the BiPr composite oxide nanowires modified glassy carbon electrode (GCE) than bare GCE. The BiPr composite oxide nanowires modified GCE possesses good electro-catalytic activity for L-cysteine detection with a pair of quasi-reversible cyclic voltammetry peaks at +0.04 V and –0.72 V for the oxidation and reduction of L-cysteine, respectively. The roles of the scan rate, electrolyte species and L-cysteine concentration on the electrochemical responses of L-cysteine at the nanowires modified GCE were systematically analyzed. The BiPr composite oxide nanowires modified GCE presents a linear response range from 0.001 to 2 mM and detection limit of 0.27 μM, good reproducibility and stability.

Controllable Synthesis of Neodymium Vanadate Nanowires Electrocatalyst for Sensitive Pyrocatechol Sensing Performance

“…There is a linear part in the low frequency region and a semi-circular part in the high frequency region of the Nyquist plots of the NdVON-modified electrode [Figure 7(c)]. The diameter of the semi-circular arc part represents the electron transfer resistance reflecting electron transfer kinetics at the electrode surface [50,51]. The diameter of the semi-circular arc part of the NdVON-modified GCE is much smaller than that of the bare electrode, suggesting that the NdVONs act as a good electron transfer interface.…”

Facile synthesis of neodymium vanadate nanoribbons and its application to highly efficient determination of cadmium ions

“…EIS provides strong evidence for analyzing the interface characteristics between the electrolyte and modified electrodes, and is also used for evaluating electron transfer performance 61‐63 . The arc radius of the Nyquist plot of EIS is proportional to transfer resistance, reflecting electron transfer kinetics at the surface of the electrodes 64,65 . Figure 3(b) shows the Nyquist plots of the bare electrode and Nd vanadate nanoribbon‐modified electrode.…”

“…[61][62][63] The arc of the Nyquist plot of EIS is proportional to transfer resistance, reflecting electron transfer kinetics at the surface of the electrodes. 64,65 Figure 4 shows the SWVs of Cd 2+ at different electrodes in 0.1 mol L −1 KCl electrolyte with or without 1 mmol L −1 Cd 2+ in +0.2 V to +1.2 V. There are no anodic peaks observed from SWVs at the bare electrode in KCl solution without or with Cd 2+ , Nd vanadate nanoribbon-modified electrode in KCl solution. The results demonstrate that bare electrode has no electrochemical activity for Cd 2+ ; also, the Nd vanadate nanoribbon-modified electrode has no electrochemical activity in KCl solution.…”