Copper-doped tellurium nanowire-based gas sensor for chemiresistive detection of nitrogen dioxide

We propose an eco-friendly hydrothermal synthesis method with glucose as reducing agent to facilitate the easy fabrication and modification of one-dimensional tellurium (Te) nanowires (NWs). Doping copper (Cu) with Te NWs significantly enhances the thermoelectric properties (e.g., Seebeck coefficient and electrical conductivity) of Te NWs. In this work, we fabricated a copper-doped Te NW-based gas sensor for the detection of nitrogen dioxide (NO₂)—a toxic air pollutant. The Cu (II) doping of Te NWs increased the number of holes and electrical conductivity, thereby enhancing the gas-sensing performance with a detection limit of 7.2 ppb. Moreover, the Cu-doped Te NW-based gas sensor exhibited a reliable NO₂-detecting response under different humidity conditions and highly selective sensing properties toward other gases. The study results show that Cu doping of Te NWs significantly improves both the thermoelectric and gas-sensing properties, thereby demonstrating the potential of Te NWs in various semiconductor application technologies.