Nitrogen, Sulfur Dual-Doped Mesoporous Carbon Modified Glassy Carbon Electrode for Simultaneous Determination of Hydroquinone and Catechol

Abstract

Lately, intensive studies showed that heteroatom doped porous carbons would contribute efficiently on the performance of novel supercapacitors and electrocatalysts. In view of the few application of dual-heteroatom doped mesoporous carbon as electrode modifier for electroanalysis so far, a nitrogen and sulfur dual-doped mesoporous carbon (N, S-MPC) was fabricated in one step and further applied as electrode component for a simultaneous determination of hydroquinone (HQ) and catechol (CC) in aqueous solution. Owing to the high N, S content, the large surface area, the abundant mesopores as well as the good conductivity of the obtained N, S-MPC, improved sensitivity and selectivity in electrochemical determination of coexisted HQ and CC isomers were achieved at a N, S-MPC modified glassy carbon electrode (N, S-MPC/GCE) in both cyclic voltammetric (CV) and differential pulse voltammetric (DPV) measurements, compared with those at bare glassy carbon electrode (GCE). The electrochemical sensor showed a wide liner range of 1–110 μM for both HQ and CC. The detection limits were about 0.056 μM and 0.209 μM for HQ and CC, respectively. The practical application of the N, S-MPC/GCE in tap water samples analyses with satisfying recoveries implies the proposed sensing platform is promising.

Mesoporous Carbon and Ceria Nanoparticles Composite Modified Electrode for the Simultaneous Determination of Hydroquinone and Catechol

“…The effect of pH on the simultaneous determination of HQ and CC was studied via CV. As depicted in Figure 7A, the CV response of 0.2 mM HQ and CC was recorded; in 0.1 M CBS with different pH values (4.0 to 7.0) at scan rate of 0.1 V s −1 ; the cathode peak potential (E pc ) and anode peak potential (E pa ) shifted negatively, indicating that protons were involved in the electrochemical redox process [46]. Furthermore, the E pa and E pc exhibited a linear relationship with increasing pH, expressed as E pa (V) = 0.42–0.049 pH (R 2 = 0.992) and E pc (V) = 0.36–0.050 pH (R 2 = 0.994), E pa (V) = 0.55–0.050 pH (R 2 = 0.993), and E pc (V) = 0.48–0.050 pH (R 2 = 0.997) for HQ and CC, respectively.…”

“…Laviron theory [49] was used to study the reaction mechanism:Ip = nFQν/4RT where n is the number of electrons, F is the Faraday constant (96485 C mol −1 ), Q is the electric quantity, R is the universal gas constant (8.314 J K −1 mol −1 ), and T is the temperature in kelvin. The n can be calculated, the values are 1.69 and 1.85 for HQ and CC, indicating that the reaction of HQ and CC in modified electrode is complex, which is not a simple two–electron process [46,47,48].…”

Recent Trends on Electrochemical Sensors Based on Ordered Mesoporous Carbon

“…The success of such reactions is easily monitored by surface analysis (using X-ray Photoelectron Spectroscopy, XPS, for example). Bulk functionalization by doping is possible by adding a nitrogen- and/or sulfur-containing dopant in the precursor synthesis medium, but this strategy ( Figure 6 B) has been applied for electroanalytical purposes only very recently (N-doping [ 107 , 108 , 109 , 110 ] or dual N,S-doping [ 111 ]). XPS and Raman spectroscopy are usually used to evidence these additional sites in OMC.…”

“…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 ...…”

“…Besides the strategies of OMC surface modification with mediators, another recent approach is the bulk functionalization via N-doping [ 49 , 107 , 108 , 109 , 110 ] (or even N,S dual-doping [ 111 ]) to generate OMC materials containing more catalytically active sites. In the field of electrochemical sensors, they are particularly suited to detection of mixtures (e.g., ascorbic acid, dopamine and uric acid [ 107 , 108 , 109 ] or hydroquinone and catechol [ 111 ]) with well-resolved electrochemical signals attributed to superior electrocatalytic behavior due to increased edge-plane defect sites [ 49 ].…”