N Doping to ZnO Nanorods for Photoelectrochemical Water Splitting under Visible Light: Engineered Impurity Distribution and Terraced Band Structure.
Solution-based ZnO nanorod arrays (NRAs) were modified with controlled N doping by an advanced ion implantation method, and were subsequently utilized as photoanodes for photoelectrochemical (PEC) water splitting under visible light irradiation. A gradient distribution of N dopants along the vertical direction of ZnO nanorods was realized. N doped ZnO NRAs displayed a markedly enhanced visible-light-driven PEC photocurrent density of ~160 μA/cm(2) at 1.1 V vs. saturated calomel electrode (SCE), which was about 2 orders of magnitude higher than pristine ZnO NRAs. The gradiently distributed N dopants not only extended the optical absorption edges to visible light region, but also introduced terraced band structure. As a consequence, N gradient-doped ZnO NRAs can not only utilize the visible light irradiation but also efficiently drive photo-induced electron and hole transfer via the terraced band structure. The superior potential of ion implantation technique for creating gradient dopants distribution in host semiconductors will provide novel insights into doped photoelectrode materials for solar water splitting.
International Research Centre for Renewable Energy &State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China.
Meng
M
Wang
School of Physics and Technology, Center for Ion Beam Application, Wuhan University, Wuhan 430072, P. R. China.
Feng
F
Ren
Canadian Light Sources Inc., 44 Innovation Boulevard, Saskatoon, S7N2V3, Canada.
Jigang
J
Zhou
School of Physics and Technology, Center for Ion Beam Application, Wuhan University, Wuhan 430072, P. R. China.
Guangxu
G
Cai
International Research Centre for Renewable Energy &State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China.
Li
L
Cai
Canadian Light Sources Inc., 44 Innovation Boulevard, Saskatoon, S7N2V3, Canada.
Yongfeng
Y
Hu
Canadian Light Sources Inc., 44 Innovation Boulevard, Saskatoon, S7N2V3, Canada.
Dongniu
D
Wang
School of Physics and Technology, Center for Ion Beam Application, Wuhan University, Wuhan 430072, P. R. China.
Yichao
Y
Liu
International Research Centre for Renewable Energy &State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China.
Liejin
L
Guo
International Research Centre for Renewable Energy &State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China.
Shaohua
S
Shen