Molecular architecture strategies for UV-enhanced NO2 sensors under ambient conditions

Abstract

Detecting nitrogen dioxide (NO₂) below sub-ppm levels is critical for mitigating health risks associated with air pollution. Carbon-based materials are promising candidates for gas sensing, but their performance depends strongly on structural and chemical tuning. Here we show that nitrogen-doped carbide-derived carbons syn­thesized using dendritic molecular architectures exhibit enhanced gas-sensing properties. The resulting 2D porous structure demonstrates p-type response to NO₂, with a sensitivity of 7.9 ± 2.8 %/ppm in dark conditions. Under ultraviolet illumination, the response increases by 150 % without inducing poisoning effects. This improvement is attributed to the combined effects of nitrogen doping, high defect concentration, and hierar­chical micro-mesoporosity. Our results demonstrate that molecular design is a powerful strategy to engineer carbon materials with tunable gas-sensing properties, offering new opportunities for next-generation detection technologies.