Detection of C₆H_6,CO₂, and H₂S gases on arsenic (As) and cobalt (Co) doped quantum dots (QDs) nanostructured materials

Gas sensors exhibit significant potential due to their widespread use in various applications, such as food packaging, indoor air quality assessment, and real-time monitoring of man-made gas emissions to mitigate global warming. The utilization of nanostructured materials for sensor and adsorbent surfaces has seen remarkable growth over time, though substantial efforts are still needed to develop more efficient adsorbents. Consequently, this study investigates the viability of metal-doped quantum dots (QDs) as prospective gas-sensing and adsorption materials. Density functional theory (DFT) calculations employing the 6-311 + G(d,p) basis set and three functionals (B3LYP, B3LYP-GD3(BJ), and ωB97XD) were utilized for this investigation. Three environmentally and health-significant gases (C6H6, CO2, and H2S) were chosen as adsorbates on arsenic (As) and cobalt (Co) functionalized QDs to assess the performance and sensing capabilities of resulting QD surfaces. The analysis encompassed computation of adsorption energy, thermodynamic properties, non-covalent interactions, natural bond orbital analysis, and other topological aspects for both the surfaces and gases. The outcomes indicate that the GP_As functionalized surface exhibits a lower energy gap, rendering it more reactive and sensitive toward the respective gases (C6H6, CO2, and H2S). Moreover, the calculated adsorption energies of the investigated systems indicate thermodynamic favorability and spontaneity. Notably, our findings suggest that QD_As surfaces possess superior adsorption potential for H2S compared to the other gases examined; nonetheless, all studied QD surfaces demonstrate significant adsorption capacities for C6H6, CO2, and H2S gases.