Hydrogen-Bonded Organic Framework-Induced RuO₂–NiO Nanotubes for Sensing Triethylamine

Triethylamine (TEA), a widely used colorless liquid with a pungent odor, poses a potential health hazards. Currently, conventional TEA sensors suffer from low sensitivity, high operating temperature, and performance degradation under high humidity. Herein, RuO2-decorated nickel oxide (NiO) heterojunctions have been fabricated via a hydrogen-bonded organic framework (HOF) (HOF)-mediated synthetic strategy for high-performance TEA sensing. Leveraging Ru3+-directed coordination with the HOF template, that is, melamine-benzene-1,3,5-tricarboxylic acid (MABTC), the hierarchical nanotubular architecture was constructed to enhance gas diffusion and active site utilization simultaneously. The engineered RuO2–NiO heterojunctions further demonstrate oxygen vacancy optimization and charge alignment to facilitate selective physisorption of TEA and improve sensing performance. The resultant sensor exhibits exceptional performance at low operating temperature (120 °C) with a response value of 37.7 to 100 ppm of TEA (a 9.2-fold sensitivity improvement over pristine NiO), rapid recovery speed (τrec = 45 s), remarkable humidity resistance, and good selectivity. Especially, the strategic incorporation of Ru3+ ions serves multiple critical functions: directed fabrication of hierarchical nanotubes, in situ generation RuO2 nanoparticles, and the integrity improvement of the nanotube during calcination. This HOF-guided heterojunction engineering strategy provides a paradigm for developing next-generation chemiresistive sensors in industrial safety, food quality monitoring, and diagnosis applications.