DFT calculation on p-xylene sensing mechanism of(C4H9NH3)2PbI4 single crystal based on physisorption

• 作者: Meng-Ya Zhu Ping He Xue-Li Yang Guang-Ze Hui Cheng-Chun Tang Guo-Feng Pan Li-Jian Bie
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: ADVANCED NANOMATERIALS FOR GAS AND HUMIDITY SENSORS
• 页码范围: 1571-1577
• 页数: 7页
• 语种: 英文

摘要

P-xylene (p-C8H10) is extremely harmful and dangerous to human health due to high toxicity and strong carcinogenicity.Exploring sensitive material to effectively detect p-xylene is of importance.In this paper,perovskite single crystal (C4H9NH3)2PbI4 has been successfully syn-thesized via solution method.The obtained product was analyzed by single crystal X-ray diffraction.With the space group Pbca,orthorhombic (C4H9NH3)2PbI4 layered per-ovskite structure consists of an extended two-dimensional network of corner-sharing PbI6 octahedron.Single layer perovskite sheets of distorted PbI6 octahedron alternated with protonated n-butylammonium cation bilayers,which offers many advantages and provides the possibility of forming a gas sensor device based on the change of resistances.Density functional theory (DFT) simulations regarding the adsorption energy revealed that this organic-inorganic hybrid perovskite compound has excellent selectivity toward p-xylene compared with other gases including C2H5OH,C6H6,CH2Cl2,HCHO,CH3COCH3 and C7H8.The calculation of electron density,density of states and electron density difference showed the sensing mechanism of p-C8H10 is mainly derived from physical adsorption-desorption in view of electron transfer.