Studies on TiNxOyFz as a visible-light-responsive photocatalyst
Studies on TiNxOyFz as a visible-light-responsive photocatalyst
复制标题
DOI：
10.1021/jp0765188
复制
发表时间：
2007-12-13
影响因子：
3.7
通讯作者：
Domen, Kazunari
中科院分区：
文献类型：
--
作者：
Maeda, Kazuhiko;Shimodaira, Yoshiki;Domen, Kazunari
研究了一种氟氧氮化钛（TiNxOyFz）作为可见光响应光催化剂。NH4TiOF3在773 K、NH3流下氮化1 h，制得具有锐钛矿晶体结构和高结晶度的细颗粒TiNxOyFz（粒径100-300 nm）。x射线衍射和吸收测量证实，TiNxOyFz材料具有与锐钛矿TiO2相似的结构特征。TiNxOyFz的能带隙估计为2.34 eV，大大小于具有相同锐钛矿晶体结构的TiO2的能带隙能量（3.26 eV）。密度泛函理论计算表明，TiNxOyFz的导带底部由空Ti3d轨道组成，掺杂能级由O2p轨道组成的价带上方禁带内的N2p轨道形成。TiNxOyFz。被证明是一种可见光驱动的光催化剂，通过从N2p掺杂水平到由空Ti3d轨道形成的导带的光激发，在长达540 nm的波长下将水氧化成分子氧。
A titanium fluorooxynitride (TiNxOyFz) is studied as a visible-light-responsive photocatalyst. Nitridation of NH4TiOF3 at 773 K for 1 h under NH3 flow yields fine particulate TiNxOyFz(particle size, 100-300 nm) with an anatase crystal structure and high crystallinity. X-ray diffraction and absorption measurements confirm that the TiNxOyFz material exhibits similar structural characteristics to anatase TiO2. The energy gap of TiNxOyFz is estimated to be 2.34 eV, substantially smaller than the band gap energy of TiO2 with the same anatase crystal structure (3.26 eV). Density functional theory calculations indicate that the bottom of the conduction band of TiNxOyFz is composed of empty Ti3d orbitals and that the doping level is formed by N2p orbitals in the forbidden band above the valence band consisting of O2p orbitals. TiNxOyFz. is demonstrated to function as a visible-light-driven photocatalyst for water oxidation into molecular oxygen at wavelengths as long as 540 nm through photoexcitation from the N2p doping level to the conduction band formed by empty Ti3d orbitals.