Defect Engineering of Green Phosphorene Nanosheets for Detecting Volatile Organic Compounds: A Computational Approach

The high performance of chemical gas detection has become an essential factor for monitoring biotoxin volatile organic compounds (VOCs). Here, using first-principles modeling, defect engineering of green phosphorene (GreenP) with heteroatom substitution and vacancy formation was proposed to obtain high sensing ability and reusability of gas sensing materials for VOC gases. Our computations suggest that pristine and S- and C-doped GreenP weakly adsorbs the VOC gases with small charge transfer, leading to almost no change in the electronic properties. Although mono- and di-vacancy GreenP substantially improves the adsorption strength, the electronic structure exhibits negligible changes upon adsorption, resulting in low sensitivity. Remarkably, Si doping improves the adsorption of carbonyl-containing compounds, including acetone, propanal, and formaldehyde, and yields major changes in the electronic properties and work function, which promote sensitivity and selectivity. In addition, their adsorption energies are moderately strong, which also allow for fast desorption at elevated temperature, resulting in high reusability. From the computational viewpoints, we proposed Si-doped GreenP as a promising candidate for gas sensing material for VOC detection.