title: Shift of the reactive species in the Sb-SnO2-electrocatalyzed inactivation of e. coli and degradation of phenol: effects of nickel doping and electrolytes.
abstract: The electrocatalytic behavior and anodic performance of Sb-SnO2 and nickel-doped Sb-SnO2 (Ni-Sb-SnO2) in sodium sulfate and sodium chloride electrolytes were compared. Nickel-doping increased the service lifetime by a factor of 9 and decreased the charge transfer resistance of the Sb-SnO2 electrodes by 65%. More importantly, Ni doping improved the electrocatalytic performance of Sb-SnO2 for the remediation of aqueous phenol and the inactivation of E. coli by a factor of more than 600% and ∼20%, respectively. In the sulfate electrolyte, the primary reactive oxygen species (ROS) identified were OH radicals (Faradaic efficiency η = 2.4%) with trace levels of ozone and hydrogen peroxide (η < 0.01%) at Sb-SnO2. In contrast, the primary ROS at Ni-Sb-SnO2 was ozone (η = 9.3%) followed by OH radicals (η = 3.7%). In the chloride electrolyte, the production of hypochlorite (OCl(-)) was higher (η = 0.73%) than that of ozone (η = 0.13%) at Sb-SnO2, whereas the level of ozone (η = 13.6%) was much higher than that of hypochlorite (η = 0.24%) at Ni-Sb-SnO2. Based on the shift of the reactive species, the primary effect of Ni doping is to catalyze the six-electron oxidation of water to ozone and inhibit the competing one or two-electron oxidation of water (generation of OH radicals, hydrogen peroxides, and hypochlorites). A range of electrochemical and surface analyses were performed, and a detailed mechanism was proposed.
authors: School of Energy Engineering, Kyungpook National University , Daegu 702-701, Korea.
authors: So Young
authors: SY
authors: Yang
authors: Dongseog
authors: D
authors: Kim
authors: Hyunwoong
authors: H
authors: Park
mesh_terms: D000965:Antimony / Q000737:chemistry*; D002384:Catalysis; D020134:Catalytic Domain; D002851:Chromatography, High Pressure Liquid; D015169:Colony Count, Microbial; D055664:Electrochemical Techniques; D004573:Electrolytes; D004926:Escherichia coli / Q000378:metabolism* / Q000648:ultrastructure; D009532:Nickel / Q000737:chemistry*; D019800:Phenol / Q000737:chemistry*; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D017971:Tin Compounds; D019800:Phenol; D009532:Nickel; D000965:Antimony; C045358:stannic oxide