Electrocatalytic activity of Pd-loaded Ti/TiO2 nanotubes cathode for TCE reduction in groundwater

WATER RESEARCH

卷:47

Article

Xie, Wenjing¹  Yuan, Songhu¹  Mao, Xuhui²  Hu, Wei¹  Liao, Peng¹  Tong, Man¹  Alshaulabkeh, Akram N.³ 

[1] China Univ Geosci, State Key Lab Biogeol & Environm Geol, Wuhan 430074, Peoples R China

[2] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Peoples R China

[3] Northeastern Univ, Dept Civil & Environm Engn, Boston, MA 02115 USA

关键词: Pd;    TiO2 nanotubes;    Electrocatalytic;    TCE;    Groundwater remediation;   

DOI  :  10.1016/j.watres.2013.04.004

来源: Elsevier

【 摘 要 】

A novel cathode, Pd loaded Ti/TiO2 nanotubes (Pd-Ti/TiO2NTs), is synthesized for the electrocatalytic reduction of trichloroethylene (TCE) in groundwater. Pd nanoparticles are successfully loaded on TiO2 nanotubes which grow on Ti plate via anodization. Using Pd-Ti/TiO2NTs as the cathode in an undivided electrolytic cell, TCE is efficiently and quantitatively transformed to ethane. Under conditions of 100 mA and pH 7, the removal efficiency of TCE (21 mg/L) is up to 91% within 120 min, following pseudo-first-order kinetics with the rate constant of 0.019 min(-1). Reduction rates increase from 0.007 to 0.019 min(-1) with increasing the current from 20 to 100 mA, slightly decrease in the presence of 10 mM chloride or bicarbonate, and decline with increasing the concentrations of sulfite or sulfide. O-2 generated at the anode slightly influences TCE reduction. At low currents, TCE is mainly reduced by direct electron transfer on the Pd-Ti/TiO2NT cathode. However, the contribution of Pd-catalytic hydrodechlorination, an indirect reduction mechanism, becomes significant with increasing the current. Compared with other common cathodes, i.e., Ti-based mixed metal oxides, graphite and Pd/Ti, Pd-Ti/TiO2NTs cathode shows superior performance for TCE reduction. (C) 2013 Elsevier Ltd. All rights reserved.

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