Electronic properties of OH–CNT–Ag composite: a combined first-principles and experimental study

Abstract

Carbon nanotube-based silver (CNT–Ag) composite has recently proved to be a sensing material due to the excellent electrical characteristics and is being considered as one of the promising sensing material candidates for flexible strain sensors. However, understanding the effect of interaction ways between Ag and CNT on conductivity is limited. Based on first-principles calculations, it was studied and compared that whether the presence of hydroxyl group affects the electronic properties of CNT–Ag for the first time. The results give an explanation for that the hydroxyl group increases the interaction of Ag and CNT, which makes conductivity better while silver clusters are often formed stably with even-number atoms. The corresponding experiment further demonstrates that silver nanoparticles (Ag NPs) are relatively dispersed uniformly and bind to CNT tightly in hydroxyl-functionalized CNT (OH–CNT). Meanwhile, the conductivity of the CNT–Ag composite improves by 95.81% with OH–CNT compared to that without OH–CNT, which confirms the calculated results. The present work provides a theoretical guide for preparing highly conductive CNT–Ag composite and would promote the application of functionalized CNT in the field of sensors’ sensing materials.