First-principles study of CO adsorption on zigzag ZnO nanoribbons towards nanosensor application

The efficient detection of toxic gases and development of compact, low dimensional sensors is the center of research activities in the past two decades. In this direction, here we gauged the potential of monatomic thick zigzag ZnO (zZnO) nanoribbons towards the sensing of most abundant toxic gas i.e. CO. The adsorption of CO molecules on zZnO nanoribbons (zZnONR) has been studied in different possible ways. It is revealed that electronic and transport properties of zZnONR are affected by the interaction of CO molecules. Moreover, it is noticed that CO molecules always bond with the nanoribbons edges through the C-side and adsorption takes place via formation of a stable chemical bond. The transport properties reveal a peculiar behavior that the current magnitude is significantly higher when CO adsorption happens at O-edge. Furthermore, the maximum current is obtained when CO is adsorbed at both the edges of ribbon. Our findings show that selective configurations of CO adsorption are helpful for the designing of nano sensors with considerably lower recovery time.