ChemInform Abstract: Two-Dimensional Layered Nanomaterials for Gas-sensing Applications

Two-dimensional (2D) nanomaterials have attracted a large amount of attention regarding gas sensing applications, because of their high surface-to-volume ratio and unique chemical or physical gas adsorption capabilities. As an important research method, theoretical calculations have been massively applied in predicting the potentially excellent gas sensing properties of these 2D nanomaterials. In this review, we discuss the contributions of theoretical calculations in the study of the gas sensing properties of 2D nanomaterials. Firstly, we elaborate on the gas sensing mechanisms of 2D layered nanomaterials, such as the traditional charge transfer mechanism, and a standard for distinguishing between physical and chemical adsorption, from the perspective of theoretical calculations. Then, we describe how to conduct a theoretical analysis to explain or predict the gas sensing properties of 2D nanomaterials. Thirdly, we discuss three important methods that have been applied in order to improve the gas sensing properties, that is, defect functionalization (vacancy, edge, grain boundary, and doping), heterojunctions, and electric fields. Among these strategies, theoretical calculations play a very important role in explaining the mechanisms underlying the enhanced gas sensing properties. Finally, we summarize both the advantages and limitations of the theoretical calculations, and present perspectives for further research on the 2D nanomaterials-based gas sensors.

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Nitrogen-Containing Gas Sensing Properties of 2-D Ti2N and Its Derivative Nanosheets: Electronic Structures Insight

Nanomaterials ◽

10.3390/nano11092459 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2459

Author(s):

Hongni Zhang ◽

Wenzheng Du ◽

Jianjun Zhang ◽

Rajeev Ahuja and Zhao Qian

Keyword(s):

Density Functional ◽

Gas Adsorption ◽

Gas Sensing ◽

Density Functional Theory Calculations ◽

Fast Response ◽

Two Dimensional ◽

Sensing Applications ◽

Sensing Material ◽

Physical Insight ◽

The Stability

In this work, the potentials of two-dimensional Ti2N and its derivative nanosheets Ti2NT2(T=O, F, OH) for some harmful nitrogen-containing gas (NCG) adsorption and sensing applications have been unveiled based on the quantum-mechanical Density Functional Theory calculations. It is found that the interactions between pure Ti2N and NCGs (including NO, NO2, and NH3 in this study) are very strong, in which NO and NO2 can even be dissociated, and this would poison the substrate of Ti2N monolayer and affect the stability of the sensing material. For the monolayer of Ti2NT2(T=O, F, OH) that is terminated by functional groups on surface, the adsorption energies of NCGs are greatly reduced, and a large amount of charges are transferred to the functional group, which is beneficial to the reversibility of the sensing material. The significant changes in work function imply the good sensitivity of the above mentioned materials. In addition, the fast response time further consolidates the prospect of two-dimensional Ti2NT2 as efficient NCGs’ sensing materials. This theoretical study would supply physical insight into the NCGs’ sensing mechanism of Ti2N based nanosheets and help experimentalists to design better 2-D materials for gas adsorption or sensing applications.

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Two-dimensional layered nanomaterials for gas-sensing applications

Inorganic Chemistry Frontiers ◽

10.1039/c5qi00251f ◽

2016 ◽

Vol 3 (4) ◽

pp. 433-451 ◽

Cited By ~ 185

Author(s):

Wei Yang ◽

Lin Gan ◽

Huiqiao Li ◽

Tianyou Zhai

Keyword(s):

Gas Sensors ◽

Critical Review ◽

Gas Sensing ◽

Black Phosphorus ◽

Two Dimensional ◽

Sensing Applications

In this critical review, we mainly focus on the current developments of gas sensors based on typical 2D layered nanomaterials, including graphene, MoS2, MoSe2, WS2, SnS2, VS2, black phosphorus (BP), h-BN, and g-C3N4.

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