Oxidation reaction of dissolved hydrogen sulfide using boron doped diamond

We studied an oxidation reaction of dissolved hydrogen sulfide using boron doped diamond (BDD) electrodes and 0.1 mol Lˉ1 KClO4 as an electrolyte. Oxidation of H2S and HSˉ started at potentials of +1.7 V and + 0.5 V (vs. Ag/AgCl), respectively. In order to study the oxidation behavior, the effects of pH and the scan rate were investigated. Moreover, as demonstrated by X-ray photoelectron spectroscopy, no sulfur fouling was detected on the BDD surface. A linear calibration curve was observed in the concentration range of 0.08–2.34 mg Lˉ1 (r2 = 0.99) with a detection limit of 0.82 μg Lˉ1 (S/N = 3). In addition, an interference test with CO2 was performed, which showed there was no significant interference to the sensor. •An oxidation reaction of dissolved hydrogen sulfide using boron doped diamond (BDD) electrodes was carefully studied.•Electrochemical oxidation of H2S and HS− were clearly observed owing to the wide potential window of BDD electrodes.•A linear calibration curve was observed with a high sensitivity (detection limit was 0.82 μgL−1).•An analytical performance using mixing gas containing CO2 was studied.