Room Temperature Gas Sensor Application of Carbon Nanowalls using Electrical Resistance Change by Surface Adsorption of Toxic Gases

•Carbon nanowalls (CNWs) used as sensing layer showed interconnected nano structure with stable electrical properties.•CNWs-based gas sensor showed positive and negative resistance change by surface adsorption of two analyte gases.•Especially, CNWs-based gas sensor showed outstanding sensing characteristics and selectivity for nitrogen dioxide.•In addition, CNWs-based gas sensor appeared evident effect of humidity on the two analyte gases.