One-pot synthesis of Mn3O4/graphitic carbon nanoparticles for simultaneous nanomolar detection of Pb(II), Cd(II) and Hg(II)

Abstract

In this paper, a facile one-step sucrose-nitrate decomposition method has been proposed to synthesis Mn 3 O 4 nanoparticles (Mns)/graphitic carbon. The prepared material has been characterized by X-ray diffraction, Fourier transform infrared spectrometer, surface area analysis and transmission electron microscopy. The prepared Mns/graphitic carbon is drop-casted on glassy carbon electrode to allow the fabrication of electrochemical sensors for the simultaneous detection of Pb(II), Cd(II) and Hg(II) at nanomolar (nM) levels in aqueous solutions via differential pulse anodic stripping voltammetry. The proposed Mns/graphitic carbon sensors exhibit a wide linear range from 20 to 680 nM towards the simultaneous sensing of Cd(II), Pb(II) and Hg(II), and the corresponding limits of detection were found to be 0.48 9 10 -11 , 9.66 9 10 -11 and 0.51 9 10 -11 M, respectively. The practical application of the proposed sensor is evaluated within a real battery, industrial and chrome plating effluents.

Design of a Sensitive Electrochemical Sensor Based on Ferrocene‐reduced Graphene Oxide/Mn‐spinel for Hydrazine Detection

“…XRD pattern of GO shows the characterstic peak at 10.5° (Figure S1, Supporting information), while the crystalline nature of the Fc−G/Mn 3 O 4 has been shown by the peaks at 18.18° (101), 29.08° (112), 32.33° (200), 36.24° (211), 44.68° (220), 51.24° (015), 60.07° (224), 64.46° (413) and 77.64° (330) (Figure 2c) were observed to be consistent with standard pattern of Mn 3 O 4 (JCPDS card no: 89‐4837) [20]. The reference peak of GO has been shifted towards 5.57° (232) indicating the interlayer spacing (d) between the layers was increased from 0.36 nm to 1.5 nm showing the covalent functionalization of ferrocene to GO.…”

“…Raman spectroscopy is a very useful technique for examining the changes in all electronic structures of prepared compound. The prepared composite shows the Raman shift value at 1356.6, 1604.3 and 657.81 cm −1 corresponding to strongly observed D band (C−C), G band (C=C) [6d] and Mn spinel [20] respectively (Figure 2d). The intensity ratio of D to G band (I D /I G ) of HOOC‐GO shows more structural defects as compared to graphene oxide [21a].…”

“…Mn 3 O 4 provides the electrocatalytic effect which electro‐catalyze the hydrazine detection. At low concentration of HyZ, the oxidation peak was shifted towards lower potential at 0.48 V and existence of a new peak was appeared at 0.56 V due to involvement of intermediate electroactive species [20], while at higher concentration, the peak was started slight shifting towards higher potential due to evolution of nitrogen gas on electrode‐electrolyte interface but it did not limit further electrochemical oxidation of HyZ. Two segmented linear calibration curves (Figure 4e and 4 f) were plotted in the concentration range of 0.045 to 108 μM and 108 to 653 μM.…”

In situ addition of graphitic carbon into a NiCo2O4/CoO composite: enhanced catalysis toward the oxygen evolution reaction

“…The results presented above suggest that the presence of graphitic carbon enhances the conductivity of the electrolyte and thereby enhances the charge and mass transfer during the OER at the surface of the metal oxide. 29 The overpotential required to produce a current density of 10 mA cm À2 exhibited by the NiCo 2 O 4 /CoO/graphitic (323 mV) is less electropositive than the overpotential required by traditionally employed electrocatalysts IrO 2 (340 mV) and RuO 2 (350 mV) and Au/NiCo 2 O 4 nanorod array (360 mV). The LSV for an IrO 2 can be seen within the inset of Fig.…”

One‐step preparation of red‐emitting carbon dots for visual and quantitative detection of copper ions

“…Excessive accumulation of heavy metal ions (such as Cr 3+ , Hg 2+ , Cd 2+ , Cu 2+ , Ag + ) in water and soil with rapid industrial growth is causing harm to the health of living organisms and human body. [ 1–5 ] Among these heavy metal ions, copper ion is special as it is an essential trace element in the human body. Deficiency in copper ions can cause impaired growth, osteoporosis, and bone abnormalities.…”