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

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. Ultrasensitive UV-photoactivated gas sensor for NO 2 detection at room temperature, produced from nitrogen-doped carbide-derived carbon materials obtained from innovative dendritic architecture strategies. The sensitive material reached LoD of 1 ppb and responses of 13.2 % for the detection of 0.5 ppm of NO 2 , coupled with high reproducibility and selectivity towards NO 2 . • Novel dendritic architectures induce effective N-doping in carbon-based material. • N-doping and hierarchical porosity enhance chemiresistive gas sensor performance. • 2D material detects NO 2 at sub-ppm level, reaching a response of 13.2 % at 0.5 ppm. • Photoactivation boosts NO 2 sensing, reaching a limit of detection as low as 1 ppb.