离解(化学)
光致发光
分解水
谱线
位阻效应
化学
氧化物
带隙
原子单位
密度泛函理论
材料科学
结晶学
催化作用
物理化学
计算化学
光电子学
立体化学
物理
有机化学
天文
光催化
量子力学
生物化学
作者
Jiaqi Xu,Xiaodong Li,Zhengyu Ju,Yongfu Sun,Xingchen Jiao,Ju Wu,Chengming Wang,Wensheng Yan,Huanxin Ju,Junfa Zhu,Yi Xie
标识
DOI:10.1002/anie.201807332
摘要
Abstract Directly splitting water into H 2 and O 2 with solar light is extremely important; however, the overall efficiency of water splitting still remains extremely low. Two types of ultrathin semiconductor layers with the same elements and the same thicknesses were designed to uncover how different atomic arrangements influence water‐splitting efficiency thermodynamically and kinetically. As an example, tetrahedrally coordinated blende and octahedrally coordinated rocksalt CoO atomic layers with nearly the same thicknesses were synthesized for the first time. The blende CoO atomic layers have a smaller E g and abundant d–d internal transition features relative to the rocksalt CoO atomic layers, which ensure enhanced visible‐light harvesting ability. Density functional theory calculations reveal that the Bader charge for Co atoms in blende CoO atomic layers is larger than that of the rocksalt CoO atomic layers, which facilitates photocarrier transfer kinetics, as verified by photoluminescence spectra and time‐resolved fluorescence emission decay spectra. In situ FTIR spectra and energy calculations reveal that the *OOH dissociation step is the rate‐limiting step, where the blende CoO atomic layers possess a smaller *OOH dissociation energy thanks to their higher Bader charge and stronger steric effect, as confirmed by the elongated Co−OOH bonds. The blende CoO atomic layers exhibit visible‐light‐driven H 2 and O 2 formation rates of 4.43 and 2.63 μmol g −1 h −1 , roughly 3.7 times higher than those of the rocksalt CoO atomic layers.
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