SCC-DFTB calculations compared NO2, NO, and N2O adsorption on pristine and sulfur-doped g-C3N4 quantum dots. Sulfur at an N-ring site reduced the band gap and produced the strongest NO2 adsorption and electronic response. This identifies a sensor candidate, not an experimentally synthesized, selective, or recoverable device.
Key findings
- Sulfur at the N-ring site reduced the band gap from 3.58 to 1.37 eV. Pristine dots weakly physisorbed the gases, while S/g-C3N4 interacted strongly; NO2 reached -3.543 eV adsorption energy and a 0.46 eV band gap. NO was moderate and N2O caused little electronic perturbation.
Why this matters globally
Low-temperature NO2 sensing could support air-quality and industrial safety, but depends on reproducible quantum-dot synthesis, selectivity, humidity response, and lifetime.
Thai researcher contribution
Physicists from Phetchabun Rajabhat, Valaya Alongkorn Rajabhat, and Kasetsart jointly modeled nanomaterial electronic structure and gas-sensing mechanisms.
Limitations to consider
This is calculation on idealized structures and SCC-DFTB depends on parameterization; no higher-level DFT benchmark or uncertainty is reported in the abstract. Only three gases were modeled, excluding O2, H2O, VOCs, and temperature. Chemisorption at -3.543 eV may slow recovery, so device sensitivity and selectivity remain unproven.
Verify the original sources
Journal of Composites ScienceRead the original article↗DOI: 10.3390/jcs10070370