TY - JOUR
T1 - Electrochemical reduction of nitrate on boron-doped diamond electrodes
T2 - Effects of surface termination and boron-doping level
AU - Kuang, Peijing
AU - Natsui, Keisuke
AU - Feng, Chuanping
AU - Einaga, Yasuaki
N1 - Funding Information:
The authors acknowledge the Inorganic Materials Chemistry Laboratory, Keio University (KU). This research work was supported by China Scholarship Council (CSC, No. 201706400005) during a visit of Peijing Kuang to KU, the Science and Technology Innovation Foundation of Dalian, China (2018J12SN080).
Funding Information:
The authors acknowledge the Inorganic Materials Chemistry Laboratory, Keio University (KU). This research work was supported by China Scholarship Council (CSC, No. 201706400005 ) during a visit of Peijing Kuang to KU, the Science and Technology Innovation Foundation of Dalian , China ( 2018J12SN080 ).
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/7
Y1 - 2020/7
N2 - This study is among the first to systematically study the electrochemical reduction of nitrate on boron-doped diamond (BDD) films with different surface terminations and boron-doping levels. The highest nitrate reduction efficiency was 48% and the highest selectivity in the production of nitrogen gas was 44.5%, which were achieved using a BDD electrode with a hydrogen-terminated surface and a B/C ratio of 1.0%. C–H bonds served as the anchor points for attracting NO3− anions close to the electrode surface, and thus accelerating the formation of NO3−(ads). Compared to oxygen termination, hydrogen-terminated BDD exhibited higher electrochemical reactivity for reducing nitrate, resulting from the formation of shallow acceptor states and small interfacial band bending. The hydrophobicity of the hydrogen-terminated BDD inhibited water electrolysis and the subsequent adsorption of atomic hydrogen, leading to increased selectivity in the production of nitrogen gas. A BDD electrode with a boron-doping level of 1.0% increased the density of acceptor states, thereby enhancing the conductivity and promoting the formation of C–H bonds after the cathodic reduction pretreatment leading to the direct reduction of nitrate.
AB - This study is among the first to systematically study the electrochemical reduction of nitrate on boron-doped diamond (BDD) films with different surface terminations and boron-doping levels. The highest nitrate reduction efficiency was 48% and the highest selectivity in the production of nitrogen gas was 44.5%, which were achieved using a BDD electrode with a hydrogen-terminated surface and a B/C ratio of 1.0%. C–H bonds served as the anchor points for attracting NO3− anions close to the electrode surface, and thus accelerating the formation of NO3−(ads). Compared to oxygen termination, hydrogen-terminated BDD exhibited higher electrochemical reactivity for reducing nitrate, resulting from the formation of shallow acceptor states and small interfacial band bending. The hydrophobicity of the hydrogen-terminated BDD inhibited water electrolysis and the subsequent adsorption of atomic hydrogen, leading to increased selectivity in the production of nitrogen gas. A BDD electrode with a boron-doping level of 1.0% increased the density of acceptor states, thereby enhancing the conductivity and promoting the formation of C–H bonds after the cathodic reduction pretreatment leading to the direct reduction of nitrate.
KW - Boron-doping level
KW - Investigation of mechanism
KW - Nitrate reduction
KW - Nitrogen gas selectivity
KW - Surface termination
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U2 - 10.1016/j.chemosphere.2020.126364
DO - 10.1016/j.chemosphere.2020.126364
M3 - Article
C2 - 32443231
AN - SCOPUS:85081284802
SN - 0045-6535
VL - 251
JO - Chemosphere
JF - Chemosphere
M1 - 126364
ER -