Hydrothermal Synthesis of Cr2Se3 Hexagons for Sensitive and Low-level Detection of 4-Nitrophenol in Water.

We report a simple hydrothermal method used for the synthesis of Cr2Se3 hexagons (h-Cr2Se3) and its application towards electrochemical sensing of 4-nitrophenol (4-NP). The formation of h-Cr2Se3 was confirmed by using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical activity of the h-Cr2Se3 modified screen-printed carbon electrode (SPCE) towards 4-NP was studied using cyclic voltammetry (CV) and amperometric i-t techniques. Typically, the obtained results were compared with those for a bare SPCE. The CV result clearly reveals that h-Cr2Se3 modified SPCE has higher catalytic activity towards reduction of 4-NP than bare SPCE. Hence, h-Cr2Se3 modified SPCE was concluded as a viable sensor for sensitive determination of 4-NP. Under optimized conditions, h-Cr2Se3 modified SPCE demonstrates the excellent capacity to detect the 4-NP in a linear range from 0.05 µM to 908.0 µM. The LOD and sensitivity in detection of 4-NP were determined at 0.01 µM and 1.24 µAµM-1 cm-2 respectively. The sensor is highly selective and stable and shows reproducible recovery of 4-NP in domestic supply and river water samples.

Synthesis and application of bismuth ferrite nanosheets supported functionalized carbon nanofiber for enhanced electrochemical detection of toxic organic compound in water samples.

Recently, the multiferroic material has fabulous attention in numerous applications owing to its excellent electronic conductivity, unique mechanical property, and higher electrocatalytic activity, etc. In this paper, we reported that the synthesis of bismuth ferrite (BiFeO3) nanosheets integrated functionalized carbon nanofiber (BiFeO3 NS/F-CNF) nanocomposite using a simple hydrothermal technique. Herein, the structural changes and crystalline property of prepared BiFeO3 NS/F-CNF nanocomposite were characterized using Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). From this detailed structural evolution, the formation of nanosheets like BiFeO3 and its nanocomposite with F-CNF were scrutinized and reported. Furthermore, the as-prepared BiFeO3 NS/F-CNF nanocomposite modified glassy carbon electrode (GCE) was applied for electrochemical detection of catechol (CC). As expected, BiFeO3 NS/F-CNF/GCE shows excellent electrocatalytic activity as well as 3.44 (F-CNF/GCE) and 7.92 (BiFeO3 NS/GCE) fold higher electrochemical redox response for CC sensing. Moreover, the proposed sensor displays a wide linear range from 0.003 to 78.02 µM with a very low detection limit of 0.0015 µM. In addition, we have validated the real-time application of our developed CC sensor in different water samples.

Two-dimensional metal chalcogenides analogous NiSe2 nanosheets and its efficient electrocatalytic performance towards glucose sensing.

Recently, 2D layered transition-metal dichalcogenide materials have received great consideration because of their unique electronic properties, large surface area and high electrocatalytic activity. In this connection, for the first time the similar nanostructured material of NiSe2 nanosheets (NiSe2-NS) has been synthesized by a facile hydrothermal method for electrocatalytic applications. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray analysis (EDX), X-ray diffraction spectrum (XRD) results confirmed the formation of NiSe2-NS with required stoichiometry and morphology. Electrochemical Impedance Spectroscopy (EIS) data indicate that electron transfer is facile at the NiSe2-NS modified glassy carbon electrode (GCE). It has been as an electrode modifier for glucose sensing applications. The electrochemical studies were performed for NiSe2-NS modified GCE using Cyclic Voltammetry (CV) and amperometric i-t techniques. The results are suggesting the effective response of NiSe2-NS/GCE with a very low limit of detection (LOD) and sensitivity of 23nM and 5.6µAµM-1cm-2 respectively. Moreover, the selectivity data exhibited excellent anti-interference property of NiSe2-NS/GCE towards glucose in the presence of possible interfering agents viz. Ascorbic acid, dopamine, glucose.