Oriented electron tunneling transport in hierarchical Ag/SiO_(2)/TiO_(2) nanobowl arrays for plasmonic solar water splitting  

作　　者：Zexin Yu Lixia Sang Angran Cao Yunlong Gao 

机构地区：[1]MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation,Beijing Key Laboratory of Heat Transfer and Energy Conversion,Beijing Municipality,Beijing University of Technology,Beijing 100124,China

出　　处：《Nano Research》2022年第2期1593-1602,共10页纳米研究（英文版）

基　　金：the National Natural Science Foundation of China(No.51776009)for their financial support.

摘　　要：Hierarchical Ag/SiO_(2)/TiO_(2) nanobowl(NB)arrays were fabricated for use as plasmonic photoanodes for solar-hydrogen conversion.The nanobowls had large pore size and were composed of an upper TiO_(2) nanoring and a lower TiO_(2) nanohole.A thin SiO_(2) inter-layer was introduced as an electron transmission channel to change the mechanism of hot electron transport.Simulations were performed to characterize the variation of electron concentration in Ag/SiO_(2)/TiO_(2) NB arrays,taking into account both the optical transition of photogenerated electrons,and electron tunneling.The multiphysics coupling function of COMSOL software provided the light source for optical transition of photogenerated electrons,and a Wentzel-Kramers-Brillouin model was employed to represent the tunneling.The results demonstrate that the TiO_(2) nanoring was a transporter,which transmitted electrons downward to the nanohole.The SiO_(2) layer replaces the Schottky barrier to become a bridge for tunneling of hot electrons in high-and low-energy states into TiO_(2).Moreover,the coverage of the SiO_(2) layer helped increase the light absorption of TiO_(2),it also reduced the near electric field coupling between Ag and TiO_(2).Accordingly,under AM 1.5 light irradiation,the photocurrent density and average hydrogen evolution rate of Ag/SiO_(2)/TiO_(2) were 1.8 and 2.2 times higher,respectively,than those of pure TiO_(2),implying far more efficient migration of carriers.

关 键 词：nanobowl TUNNELING Wentzel-Kramers-Brillouin(WKB)approximation hot electron SiO_(2)layer 

分 类 号：TN3[电子电信—物理电子学]