Nitrobenzene In Water Samples Research Articles

Designing a three-dimensional CoFe2O4 cross-frame wrapped with carbon nanotubes for monitoring the environmental pollutant nitrobenzene

In this study, we employ a catalytic system derived from a zeolitic imidazolate framework (ZIF), comprising carbon nanotube-wrapped CoFe2O4 with a modified 3D cross morphology. The seamless transition between ionic valence states in CoFe2O4 contributes to enhanced material conductivity, illustrating a significant synergistic coupling effect. The 3D matrix has the capacity to generate a greater number of active sites and exhibit a high surface area. The generation of nanotubes provides additional channels for electron transport, thereby improving the charge transfer efficiency and enhancing the electrochemical sensing capability of the system. The synthesized material demonstrates outstanding electrochemical sensing capabilities for nitrobenzene, exhibiting impressive sensitivity with a remarkably low limit of detection at 0.013 μM and a broad linear response range (0.06–414.9 μM), heightened sensitivity, excellent repeatability, and superior selectivity. Furthermore, the quantification of trace nitrobenzene in water samples demonstrates a recovery rate within the range of 96.0 %–102.8 %. Consequently, this material presents itself as a promising catalyst for electrochemical analysis and introduces a novel approach for detecting low concentrations of nitrobenzene.

Flower-like strontium molybdate anchored on 3D N-rich reduced graphene oxide aerogel composite: An efficient catalyst for the detection of lethal pollutant nitrobenzene in water samples

Nitrobenzene (NB) is a carcinogenic water pollutant that can have dangerous effects on humans, animals, and the environment even in trace amounts. It can persist in contaminated sites and leach into the adjacent aquatic environment. Therefore, the detection of trace amounts of NB is of great interest. To address this challenge, we have fabricated strontium molybdate microflowers (SrMoO4, SMO MFs) grown on nitrogen-rich, porous three-dimensional (3D) reduced graphene oxide aerogels (SMO/N-rGO) for sensitive detection of NB in water samples. The 3D N-rGO and SMO/N-rGO composites were prepared by simple hydrothermal and precipitation methods. The fabricated SMO/N-rGO composites exhibited a porous and 3D structure with a strong synergistic effect between the SMO MFs and the N-rich porous rGO sheets with open voids that facilitate the diffusion of NB. The electrochemical detection of NB at the SMO/N-rGO modified electrode was significantly enhanced. Using amperometry (i-t), the modified SMO/N-rGO sensor was shown to have two linear response ranges in the sensing of NB, with the lower linear concentration range from 7.1 nM to 1.0 mM and the higher linear concentration range varying from 1.1 mM to 2.5 mM. In addition, the limit of detection (LOD) was calculated to be 2.1 nM using the amperometric (i-t) technique. Common nitro derivatives, biomolecules, and cations often found in water systems had no influence on the detection of NB. At the same time, a good recovery of 96.1–99.6% was obtained for real-time monitoring analysis in tap and lake water samples. In this work, new electrochemical sensors for monitoring various pollutants are developed based on anchoring conductive metal oxide electrocatalysts on porous 3D carbon aerogels.

Design three-dimensional CoFe2O4 nanocage via ion exchange route for ultra-sensitive electrochemical sensing of nitrobenzene

Bimetallic transition metal oxide materials have rich valence states, good biocompatibility, conductivity, high stability, and satisfactory catalytic performance, and stand out among many materials. Therefore, we develop a simple synthesis method of CoFe2O4 nanocage by ion exchange for the detection of nitrobenzene (NB) in this work, which uses the zeolitic imidazolate framework-67 (ZIF-67) as cobalt source and three-dimensional hollow organic framework Co-Fe PBA as precursor. The continuous conversion between ionic valence states in CoFe2O4 enhances the conductivity of the material, showing a good synergistic coupling effect. The low-density hollow structure of nanocage offers various types of sites for adsorbing reactants, and the thin shell structures provide more channels for ion migration and electron transport, facilitate charge transfer, and further improve their electrical sensing ability. Electrochemical tests proved that the material demonstrated excellent electrocatalytic activity for NB, with the limit of detection as low as 0.038 μM, a wide linear response (0.05–1664.55 μM), higher sensitivity, good repeatability, long-term stability and selectivity. More importantly, the sensor has been successfully applied to the determination of trace NB in water samples with satisfactory recovery (98.7%–104.7%). This work provides a novel idea for the detection of low content of NB and expands the application of bimetallic oxide materials in the sensing field.

Integrating graphene oxide with magnesium oxide nanoparticles for electrochemical detection of nitrobenzene

Accurate detection of highly toxic aromatic nitro compounds in the water medium is urgent for the protection of human health and eco system. In the present study, we report the graphene oxide/ magnesium oxide nanocomposite (GO/MgO-NC) has been proposed for electrochemical analysis of nitrobenzene (NBZ) in water samples. The GO/MgO-NC was characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscope, transmission electron microscopy, and energy dispersive X-ray analysis. Likewise, the electrochemical behaviour of NBZ was investigated through cyclic voltammetry and differential pulse voltammetry. The GO/MgO-NC electrode shows an excellent NBZ sensing properties compared to other electrodes. Under optimized conditions, the GO/MgO-NC/GCE can well measure the concentrations of NBZ in the range of 0.1–38.9 µM and 58.5–2333.5 µM with a low limit of detection of 0.01 µM. Besides, the GO/MgO-NC/GCE exhibits excellent selectivity, repeatability, reproducibility and stability. More importantly, the proposed GO/MgO-NC/GCE was further expanded to quantify NBZ in water samples with recoveries between 99.35–99.80%, providing an effective approach for the trace of NBZ in environmental medium.

A Facile synthesis of ultra-small cerium oxide nanoparticles for enhanced Electrochemical Detection of Nitrobenzene in water samples

A Facile synthesis of ultra-small cerium oxide nanoparticles for enhanced Electrochemical Detection of Nitrobenzene in water samples

A simple electrochemical platform for detection of nitrobenzene in water samples using an alumina polished glassy carbon electrode

In this work, we report a selective electrochemical sensing of nitrobenzene (NB) using an alumina (γ-Al2O3) polished glassy carbon electrode (GCE) for the first time. The scanning electron microscopy studies confirm the presence of alumina particles on the GCE surface. X-ray photoelectron spectroscopy studies reveal that the utilized alumina is γ-Al2O3. The alumina polished GCE shows an enhanced sensitivity and lower overpotential toward the reduction of NB compared to unpolished GCE. The differential pulse voltammetry response was used for the determination of NB and it shows that the reduction peak current of NB is linearly proportional to the concentrations of NB ranging from 0.5 to 145.5μM. The limit of detection is found to be 0.15μM based on 3σ. The fabricated electrode exhibits its appropriate selectivity towards NB in the presence of a range of nitro compounds and metal ions. The good practicality of the sensor in various water samples reveals that it can be a promising electrode material for practical applications. In addition, the proposed NB sensor is simple and cost effective one when compared with previously reported NB sensors in the literature.

Preparation of Magnetic Graphene Nanocomposites for Fast Detection of Nitrobenzene in Environmental Water Samples by GC–MS

In this work, magnetic graphene nanocomposites were synthesized via hydrothermal reaction and used as an effective adsorbent to extract and concentrate nitrobenzene in water samples, followed by analysis using gas chromatography-mass spectrometry. The properties of the magnetic nanocomposites were characterized by Fourier transform infrared analysis, transmission electron microscopy, and scanning electron microscopy. The nanocomposites have a distinct structure with the magnetite particles scattered over the surface of the graphene. Due to the unique structure, they not only adsorb the target compound strongly, but also have excellent magnetic response that allows fast separation from water. All the experimental parameters affecting the extraction efficiency, including the amounts of sorbents, eluting solvents and volume, adsorption and desorption time were investigated and optimized. Under the optimum conditions, validation experiments showed a good linearity (r 2 = 0.9999) at the range of 5–1,000 μg/L, satisfactory precision (RSD of intra-day = 3.3 % and RSD of inter-day = 3.9 %), high recovery of 77.3 % for 500 μg/L and 82.5 % for 100 μg/L and 84.7 % for 50 μg/L, respectively, and low detection limit of 0.01 μg/L for nitrobenzene in aqueous solutions. Finally, the magnetic graphene nanocomposites were successfully applied to detect nitrobenzene in real-world water samples and showed promising results.