# Detection of nitro-aromatics using C5N2 as an electrochemical sensor: a DFT approach

## TL;DR

This paper explores using a C5N2 material as a sensor to detect harmful nitroaromatic compounds like picric acid, TNT, and 1,3-DNB through computational methods.

## Contribution

The study introduces C5N2 as a novel electrochemical sensor for nitroaromatics and identifies picric acid as the most strongly interacting compound.

## Key findings

- Picric acid@C5N2 complex showed the highest interaction energy.
- C5N2 demonstrated high sensitivity and selectivity towards picric acid compared to other nitroaromatics.
- Electronic and recovery time analyses confirmed C5N2's efficiency as a sensor.

## Abstract

Nitroaromatics impose severe health problems and threats to the environment. Therefore, the detection of such hazardous substances is essential to save the whole ecosystem. Herein, the C5N2 sheet is used as an electrochemical sensor for the detection of 1,3-dinitrobenzene (1,3-DNB), trinitrotoluene (TNT), and picric acid (PA) using the PBE0/def2SVP level of theory as implemented in Gaussian 16. The highest interaction energy was observed for the picric acid@C5N2 complex. The trend in interaction energies for the studied system is PA@C5N2 >TNT@C5N2 >1,3-DNB@C5N2. The studied systems were further analysed by qualitative and quantitative analyses to determine the interactions between the nitroaromatic analytes and the C5N2 sheet. Electronic properties of all analytes@C5N2 complexes have been examined by NBO, EDD, FMO and DOS analysis. QTAIM analysis depicts the stronger non-covalent interactions for the PA@C5N2, which shows consistency with interaction energy and NCI analysis. Furthermore, NBO and FMO analyses show that the C5N2 substrate exhibits high sensitivity and selectivity towards the picric acid compared to TNT and 1,3-DNB nitroaromatics. EDD and DOS analyses are in agreement with NBO and FMO analyses. Furthermore, the recovery time of the studied system has been computed to determine the efficiency of C5N2 material as an electrochemical sensor. Overall, the results show that carbon nitride can be a good sensor for the detection of nitroaromatics.

Nitroaromatics are hazardous pollutants. This study investigates C5N2 as a sensor for 1,3-DNB, TNT, and picric acid using DFT. Picric acid exhibited the strongest interaction, indicating C5N2's potential as a selective sensor for nitroaromatics.