First-Principles Insight into Pd-Doped C3N Monolayer as a Promising Scavenger for NO, NO2 and SO2.

Qu Zhou,Ruochen Peng,Wen Zeng

doi:10.3390/nano11051267

Qu Zhou, Ruochen Peng + Show 1 more

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https://doi.org/10.3390/nano11051267

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Abstract

The adsorption and sensing behavior of three typical industrial toxic gases NO, NO2 and SO2 by the Pd modified C3N monolayer were studied in this work on the basic first principles theory. Meanwhile, the feasibility of using the Pd doped C3N monolayer (Pd-C3N) as a sensor and adsorbent for industrial toxic gases was discussed. First, the binding energies of two doping systems were compared when Pd was doped in the N-vacancy and C-vacancy sites of C3N to choose the more stable doping structure. The result shows that the doping system is more stable when Pd is doped in the N-vacancy site. Then, on the basis of the more stable doping model, the adsorption process of NO, NO2 and SO2 by the Pd-C3N monolayer was simulated. Observing the three gases adsorption systems, it can be found that the gas molecules are all deformed, the adsorption energy (Ead) and charge transfer (QT) of three adsorption systems are relatively large, especially in the NO2 adsorption system. This result suggests that the adsorption of the three gases on Pd-C3N belongs to chemisorption. The above conclusions can be further confirmed by subsequent deformable charge density (DCD) and density of state (DOS) analysis. Besides, through analyzing the band structure, the change in electrical conductivity of Pd-C3N after gas adsorption was studied, and the sensing mechanism of the resistive Pd-C3N toxic gas sensor was obtained. The favorable adsorption properties and sensing mechanism indicate that the toxic gas sensor and adsorbent prepared by Pd-C3N have great application potential. Our work may provide some guidance for the application of a new resistive sensor and gas adsorbent Pd-C3N in the field of toxic gas monitoring and adsorption.

Highlights

Nowadays, with the progress of the economy and the acceleration of industrialization, the problem of industrial waste gases is becoming more and more serious
The adsorption performance and sensing mechanism of the Pd-C3 N monolayer for three kinds of industrial toxic gases NO, NO2 and SO2 were explored based on first principles
The deformed charge density (DCD), density of state (DOS) and band structure were considered to study the change in electronic behavior and conductivity of Pd-C3 N after adsorbing gas

Summary

Introduction

With the progress of the economy and the acceleration of industrialization, the problem of industrial waste gases is becoming more and more serious. NO, NO2 and SO2 are several typical toxic industrial waste gases. Finding an effective method of detecting and adsorbing these toxic gases is of great significance to protect our living environment. Since the typical two-dimensional (2D) material graphene was successfully synthesized, 2D nanomaterial, such as transition metal dihalogen compounds [3–5], silicene [6,7], germanene [8,9], and stannene [10,11], have attracted extensive attention in academia. Researchers began to explore novel two-dimensional graphene-like materials, such as metal nitrides and carbides [18], III-V nitrides [19–21], etc. Among these new graphene-like materials, a planar honeycomb C3 N

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