Yuan Hongbo, Yan Hong, Meng Yu, Matsushita Yoshitaka, Yamaura Kazunari, Tsujimoto Yoshihiro
Research Center for Materials Nanoarchitechtonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Graduate School of Chemical Sciences and Engineering, Hokkaido University, North 10 West 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
Inorg Chem. 2024 Aug 19;63(33):15443-15450. doi: 10.1021/acs.inorgchem.4c02546. Epub 2024 Aug 2.
Single crystals of a new titanium oxysulfide, LiLaTiSO, were grown from a KI molten salt. Single-crystal X-ray diffraction analysis revealed that LiLaTiSO crystallizes in the space group with lattice parameters of = 11.7319(4) Å, = 3.94787(14) Å, and = 20.6885(6) Å. In this structure, the one-dimensional chains of corner-sharing TiOS octahedra are further corner-linked via equatorial and apical oxygen atoms to form unique corrugated two-dimensional perovskite-type layers in the plane with one octahedral thickness. These layers were intervened along the -axis by the LaS rock-salt layers corrugated concomitantly with the perovskite-type layers, and LiOS tetrahedral chains were located between these two types of two-dimensional layers. LiLaTiSO can be viewed as a modified KNiF-type structure with TiOS octahedral layers stacked in a zigzag manner along the axis. The oxysulfide has a direct-type band gap of 1.85 eV, based on UV-vis-NIR diffuse reflectance measurements. First-principles calculations showed that the conduction band minimum mainly consists of Ti 3 orbitals, and the valence band maximum consists of S 3 O 2, and Li 2s orbitals. The electronic structures near the Fermi level are similar to those of the structurally related photocatalytic oxysulfides YTiSO and LaTiCuSO.
一种新型硫氧化钛LiLaTiSO的单晶是从碘化钾熔盐中生长出来的。单晶X射线衍射分析表明，LiLaTiSO结晶于空间群，晶格参数为 = 11.7319(4) Å， = 3.94787(14) Å，以及 = 20.6885(6) Å。在这种结构中，由共角顶的TiOS八面体组成的一维链通过赤道面和顶点氧原子进一步角连接，在 平面上形成独特的具有一个八面体厚度的波纹状二维钙钛矿型层。这些层沿着 轴被与钙钛矿型层伴随波纹状的LaS岩盐层所间隔，并且LiOS四面体链位于这两种二维层之间。LiLaTiSO可以被看作是一种具有沿 轴呈锯齿状堆叠的TiOS八面体层的改性KNiF型结构。基于紫外-可见-近红外漫反射测量，该硫氧化物具有1.85 eV的直接带隙。第一性原理计算表明，导带最小值主要由Ti 3轨道组成，价带最大值由S 3 O 2和Li 2s轨道组成。费米能级附近的电子结构与结构相关的光催化硫氧化物YTiSO和LaTiCuSO相似。
