The adsorption characteristic of As2, As2O3, Pb, PbO on double transition-metal pyridine-tetranitrogen-annulene membrane

Abstract

The arsenic and lead compounds produced by coal combustion have serious impacts on human health and the environment, making it urgent to simultaneously remove arsenic and lead. In this work, the adsorption characteristics of As₂, As₂O₃, Pb and PbO on 2D Double Transition-Metal Pyridine-Tetranitrogen-Annulene membrane (DTM-PTA, TM=Co, Cu, Zn) are investigated through density functional theory calculations. The adsorption energy, bonding mechanism, electronic and magnetic properties are analyzed in detailed. Firstly, the distribution density of transition metal atoms as adsorption active sites is high, which is conducive to the adsorption of molecules. The results demonstrate that the DCo-PTA is a promising adsorbent for simultaneously removing As₂, As₂O₃, Pb and PbO with highest adsorption energy. According to the variation of magnetic moment, DCu-PTA and DZn-PTA can detect the adsorption of PbO in the mixture of As₂, As₂O₃, Pb and PbO. In addition, the adsorbed molecules can regulate the array of spin electron. Although temperature hinders the adsorption process of molecules, DCo-PTA can still spontaneously adsorb these molecules within the temperature range of 300–1000 K. This indicates that DCo-PTA is an excellent adsorbent which can work in high temperature.