Wang Rong, Lu Shiyu, Jiang Pengfei, Lu Guangxiang, Zhang Han, Jia Bi, Di Yongjiang, Ma Yilong, Yang Xiaohui
School of Metallurgy and Materials Engineering, Chongqing University of Science & Technology, Chongqing 401331, People's Republic of China.
College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, People's Republic of China.
Inorg Chem. 2023 Apr 10;62(14):5872-5879. doi: 10.1021/acs.inorgchem.3c00859. Epub 2023 Mar 28.
The d metal oxides with low effective mass and high mobility of photoexcited electrons have received much attention in photocatalytic water splitting. However, there are still challenges in practical application due to insufficient visible light absorption. Here, an unusual phenomenon of the In cation in PtIn(GeO)O and PtIn(Ga/InO) with a narrow band gap is systematically investigated using density functional theory calculations. According to chemical bond analysis, the final band edge structure results from the interaction between the empty In-5p orbitals and the occupied antibonding state of the In 5s-O 2p orbitals as well as the further hybridization of adjacent In cations in PtIn octahedrons. The unique bonding characteristic of In cations endows them with a narrow band gap and visible light response ability. Moreover, the occupied antibonding state could weaken the strength of the In-O covalent bond and strengthen the orbital hybridization of the In-In bond, causing the conduction band minimum to be located in the electroactive In cavity. This work reveals the origin of the narrow band gap of PtIn(GeO)O and PtIn(Ga/InO) in view of bond theory and shows that they are promising semiconductors for the application of photocatalytic H generation.
具有低有效质量和高光激发电子迁移率的d金属氧化物在光催化水分解方面备受关注。然而，由于可见光吸收不足，其在实际应用中仍面临挑战。在此，利用密度泛函理论计算系统研究了具有窄带隙的PtIn(GeO)O和PtIn(Ga/InO)中In阳离子的异常现象。根据化学键分析，最终的能带边缘结构是由空的In-5p轨道与In 5s-O 2p轨道的占据反键态之间的相互作用以及PtIn八面体中相邻In阳离子的进一步杂化所致。In阳离子独特的键合特性赋予它们窄带隙和可见光响应能力。此外，占据的反键态会削弱In-O共价键的强度并增强In-In键的轨道杂化，导致导带最小值位于电活性In空穴中。这项工作从键理论的角度揭示了PtIn(GeO)O和PtIn(Ga/InO)窄带隙的起源，并表明它们是用于光催化产氢应用的有前景的半导体。
