DFT calculation on p‐xylene sensing mechanism of (C <sub>4</sub> H <sub>9</sub> NH <sub>3</sub> ) <sub>2</sub> PbI <sub>4</sub> single crystal based on physisorption
Mengya Zhu, Ping He, Xueli Yang, Guangze Hui, Chengchun Tang, Guofeng Pan, Li‐Jian Bie
Abstract
Abstract P‐xylene (p‐C 8 H 10 ) 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 (C 4 H 9 NH 3 ) 2 PbI 4 has been successfully synthesized via solution method. The obtained product was analyzed by single crystal X‐ray diffraction. With the space group Pbca, orthorhombic (C 4 H 9 NH 3 ) 2 PbI 4 layered perovskite structure consists of an extended two‐dimensional network of corner‐sharing PbI 6 octahedron. Single layer perovskite sheets of distorted PbI 6 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 C 2 H 5 OH, C 6 H 6 , CH 2 Cl 2 , HCHO, CH 3 COCH 3 and C 7 H 8 . The calculation of electron density, density of states and electron density difference showed the sensing mechanism of p‐C 8 H 10 is mainly derived from physical adsorption–desorption in view of electron transfer.