Development of a Boron-Doped Diamond Electrode for the Simultaneous Detection of Cd2 + and Pb2 + in Water

Abstract

Mercury film electrodes used in in-situ monitoring systems suffer from the drawbacks of secondary pollution and attenuation. To overcome these problems, a boron-doped diamond (BDD) film electrode was developed that was non-polluting and could be used for simultaneous detection and long durations. The concentrations of Cd 2 + and Pb 2 + in mixed solution were measured simultaneously, and the detection performances of the mercury film and BDD electrodes were systemically compared, to evaluate the feasibility of replacing mercury film electrodes with BDD electrodes. The effects of enrichment time and electrode surface state on the stripping peak currents of Cd 2 + and Pb 2 + were investigated. Optimum conditions were an enrichment time of 200 s and a hydrogen terminated electrode surface state. The optimized BDD electrode exhibited good performance characteristics: 1) The linear relationship between the ion concentration and the peak current was excellent (linear correlation coefficients (R 2 ) of the calibration curves for Cd 2 + and Pb 2 + were 0.995 and 0.998, respectively). The spiked recovery ranges of Cd 2 + and Pb 2 + in three spike experiments were 93.5% to 99.4% and 93.7% to 101.3%, respectively. 2) The detection limits for Cd 2 + and Pb 2 + were low, 3.39 μg/L and 3.62 μg/L, respectively. The BDD electrode had good reproducibility: relative standard deviations (RSD) of Cd 2 + and Pb 2 + obtained from 7 replicate experiments were 1.603% and 3.819%, respectively. After comprehensive data comparison of the detection performance for mercury film and BBD electrodes, it was concluded that the BDD electrode could replace mercury film electrodes in insitu monitoring systems, having the advantage of allowing simultaneous detection, being nonpolluting, and able to function for long-durations.

A Nanograss Boron and Nitrogen Co-Doped Diamond Sensor Produced via High-Temperature Annealing for the Detection of Cadmium Ions

“…These results verify that the NGBND film may potentially be utilized for Cd 2+ detection. Compared to the reported diamond electrodes used for detecting Cd 2+ and listed in Table 1, the NGBND electrode has a good linear range and a greater detection limit than the other diamond electrodes [48][49][50][51][52][53][54][55].…”

Diamond-Based Electrodes for Detection of Metal Ions and Anions

“…In terms of the interference and drinking water studies, this design was exceptional. Pei et al proposed the replacement of mercury film electrode by BDD with B/C ratio of 2.4% towards simultaneous detection of Cd 2+ and Pb 2+ [ 75 ], wherein the sensing effect of hydrogen-terminated electrode (H-BDD) and oxygen-terminated electrode (O-BDD) was demonstrated by SWASV studies (scan range = +0.8 to −0.8 V; SCE and Pt were used as reference and counter electrodes; enrichment time of 200 s; scan speed 50 mV s −1 ; NaAc-HAc buffer at pH 4.68). The H-BDD showed greater sensitivity to Cd 2+ and Pb 2+ with linear correlations of 0.05–4 µM and 0.05–8 µM and LODs of 30.16 and 17.47 nM, respectively.…”

“…Thus, careful optimization becomes essential. Table 1 summarizes the doping concentrations of specific atoms, methods of detection, linear regressions, and LODs of nanodiamond-based electrodes towards metal ions [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 ].…”