Ordered Mesoporous Carbon Decorated with Magnetite for the Detection of Heavy Metals by Square Wave Anodic Stripping Voltammetry

Abstract

In this work, oxidized ordered mesoporous carbon (OMC-OXI) decorated with magnetite (OMC-OXI-Fe) was synthesized via a soft template technique in combination with a solvothermal method. The OMC-OXI-Fe was characterized by Raman spectroscopy, X-ray diffraction, nitrogen adsorption-desorption, scanning electron microscopy and thermal gravimetric analysis, indicating that the material keeps the OMC structure. The prepared material was used as an electrochemical sensor for the single and combined detection of Cd(II), Cu(II), Hg(II), and Pb(II) ions by square-wave anodic stripping voltammetry (SWASV). The electrochemical results showed that incorporation of magnetite did not modify the charge transfer properties, and maintained the available surface area for the metal ion detection. OMC-OXI-Fe presented a very favorable sensitivity (145.75 μA mg−1 L) and LOD (1.57 μg L−1) for Pb(II), while the responses to Cu(II), Cd(II) and Hg(II) were much lower. These results indicated that the magnetic properties of the modified electrode increased the individual sensitivity for Pb(II) detection and maintained the capacity of simultaneous detection for the studied heavy metal ions. The combination of magnetic mesoporous carbon and electrochemical pulse techniques is a suitable and practical alternative method for the electrochemical detection of hazardous metallic ions in water for human use.

Recent Trends on Electrochemical Sensors Based on Ordered Mesoporous Carbon

“…Various approaches can be distinguished: The simplest way is surface oxidation to generate a high density of oxygen-containing groups (carboxylic acid, phenol, carbonyl, etc.) [ 105 , 106 ] or surface grafting of reactive functions (e.g., amine) [ 50 ] ( Figure 6 A). The success of such reactions is easily monitored by surface analysis (using X-ray Photoelectron Spectroscopy, XPS, for example).…”

“… Probably the most widely-used approach is the immobilization of noble metal catalysts in the form of nanoparticles (NPs) or electrogenerated deposits [ 128 , 132 , 134 , 139 , 140 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 ] (or even bimetallic NPs [ 156 , 157 ]), which can be formed by either impregnation of metal precursors and subsequent reduction or from nanoparticles suspensions or slurries, or other NPs/deposits (metal oxides or hydroxides, metal sulfides, etc. [ 106 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 ]) accommodated to OMC by impregnation ( Figure 6 D). The last category is that of conducting and/or redox polymers that have been generated onto OMC by electropolymerization of previously impregnated monomers ( Figure 6 E), exploiting both the conductivity and large surface area of OMC materials.…”

“…The electrochemical sensors based on functionalized OMC [ 24 , 26 , 49 , 50 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 139 , 140 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 ...…”

Coupling Square Wave Anodic Stripping Voltammetry with Support Vector Regression to Detect the Concentration of Lead in Soil under the Interference of Copper Accurately

“…Square wave anodic stripping voltammetry (SWASV), as an electrochemical analysis technology, was widely applied for the detection of HMs [6,7]. SWASV, possessing many advantages of low cost, high sensitivity, excellent selectivity, and fast detection, was a good alternative to spectroscopic analysis methods [8][9][10], such as atomic absorption spectroscopy (AAS) and inductively coupled plasma-atomic emission spectroscopy. During the analysis of HMs by using SWASV, all target HMs were electroplated onto the surface of the working electrode (WE) in the electrodeposition step and then stripped off the WE surface in the electroelution process.…”

Comparison between Modified and Unmodified Carbon Paste Electrodes for Hexavalent Chromium Determination

“…Extreme toxicity of heavy metals and their adverse effects on the environment has engendered enormous necessity to develop selective, low cost, cheap and fast methods to detect them . Among these heavy metals we find chromium, on one hand, trivalent chromium is an essential element for human health, and its insufficiency increases the risk factors associated with diabetes and cardiovascular diseases .…”