School of Energy Engineering, Kyungpook National University , Daegu 702-701, Korea.
Environ Sci Technol. 2014;48(5):2877-84. doi: 10.1021/es404688z. Epub 2014 Feb 24.
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.
比较了硫酸根和盐酸盐电解液中 Sb-SnO2 和掺镍 Sb-SnO2（Ni-Sb-SnO2）的电催化行为和阳极性能。镍掺杂将 Sb-SnO2 电极的使用寿命提高了 9 倍，并将其电荷转移电阻降低了 65%。更重要的是，Ni 掺杂使 Sb-SnO2 对水中苯酚的修复和大肠杆菌灭活的电催化性能分别提高了 600%和 20%以上。在硫酸盐电解液中，在 Sb-SnO2 上主要的活性氧物种（ROS）是羟基自由基（法拉第效率 η = 2.4%），臭氧和过氧化氢的浓度很低（η < 0.01%）。相比之下，在 Ni-Sb-SnO2 上主要的 ROS 是臭氧（η = 9.3%），其次是羟基自由基（η = 3.7%）。在氯化物电解液中，次氯酸盐（OCl(-)）的生成量高于 Sb-SnO2（η = 0.73%），而臭氧的生成量（η = 0.13%），在 Ni-Sb-SnO2 上臭氧的生成量（η = 13.6%）远高于次氯酸盐（η = 0.24%）。基于活性物质的迁移，Ni 掺杂的主要作用是催化水的六电子氧化生成臭氧，并抑制水的竞争一或二电子氧化（生成羟基自由基、过氧化氢和次氯酸盐）。进行了一系列电化学和表面分析，并提出了详细的机制。
