The Electrocatalytic Activities Research And The Fabrication Of Sensors Based On Metallic Oxide Nanomaterials

Electro-sensing has attracted numorous interests in rencent years. In order to improve theresponse activities of the sensor, decrease the cost and improve the detecting avtivities etc,nanoporous (NP) Fe2O3/CoO composites were fabricated by a simple and facile dealloyingmethod to construct excellent electrochemical sensor. The NP-Fe2O3/CoO composites havebeen characterized in detail in current work and were employed to detect H2O2, nitrite, urineacid, dopamine, and ascorbic acid.The main contents of this paper:1. Refining ternary FeCoAl alloy with uniform and controllable components as precursor,NP-Fe2O3/CoO composites were straightforwardly fabricated by dealloying strategy.2. Electron microscopy characterization demonstrates that FeCoAl ternary alloy can beselectively etched in a low concentration of NaOH solution (2mM) to generate a nanoparticlestructure with a typical diameter around80nm. EDS, XPS, XRD, SEM, TEM etc. wereemployed to characterize the prepared nanoporous materials. The nanoparticles consist ofopen three-dimensional bicontinuous nanoporous structure with uniform pore and ligamentdistribution around10nm. And the resulted sample is confirmed to be a mixture of Fe2O3andCoO species.3. Without any activation pretreatment, NP-Fe2O3/CoO composites exhibit excellentelectro-detection activity toward H2O2, such as an excellent sensing performance in a widelinear sensing region from0.05to4.85mM H2O2, fast amperometric response (<2s), and alower detection limit to0.1μM.4. NP-Fe2O3/CoO composites have high electrochemical sensing activity toward nitritewith a wide linear range of0.2-16.2mM, a fast response less than3s, and a low detection limitas0.1μM. In particular, NP-Fe2O3/CoO composites behave remarkable sensing durability withalmost no activity loss towards nitrite detection over4000s. Along with these attractivefeatures, the as-made NP-Fe2O3/CoO composites are effective for determination of nitrite insausage samples.5. NP-Fe2O3/CoO composites exhibit excellent electrooxidation activity toward dopamine (DA), uric acid (UA), and ascorbic acid (AA) without any activation pretreatment. Foramperometric biosensing applications, the electrochemical detections of DA, UA, and AA onNP-Fe2O3/CoO composites display fast response (within2s), and low detection limit0.2μM,0.1μM and0.1μM respectively. NP-Fe2O3/CoO composites exhibit wide linear detectionranges of DA (2.0-285μM), AA (5.0-625μM), and UA (0-285μM).6. The as-made composites also behave as a good anti-interference towards glucose.Furthermore, the sensor based on NP-Fe2O3/CoO composites also exhibits excellentlong-term stability and reproducibility.