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化学进展 2021, Vol. 33 Issue (2): 232-242 DOI: 10.7536/PC200506 前一篇   后一篇

• 综述 •

气敏新材料MXenes在呼出气体传感器中的应用

朱继秀1, 陈巧芬2, 倪梯铜1, 陈爱民1,*(), 邬建敏2,*()   

  1. 1 浙江工业大学化学工程学院 杭州 310014
    2 浙江大学化学系分析化学研究所 杭州 310058
  • 收稿日期:2020-05-06 修回日期:2020-08-10 出版日期:2020-10-15 发布日期:2020-10-15
  • 通讯作者: 陈爱民, 邬建敏
  • 基金资助:
    国家自然科学基金项目(21575127); 浙江省自然科学基金项目(LY19B050004)
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Application for Exhaled Gas Sensor Based on Novel Mxenes Materials*

Jixiu Zhu1, Qiaofen Chen2, Titong Ni1, Aimin Chen1,*(), Jianmin Wu2,*()   

  1. 1 College of Chemical Engineering, Zhejiang University of Technology,Hangzhou 310014, China
    2 Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
  • Received:2020-05-06 Revised:2020-08-10 Online:2020-10-15 Published:2020-10-15
  • Contact: Aimin Chen, Jianmin Wu
  • About author:
    * Corresponding author e-mail: (Aimin Chen);
    (Jinmin Wu)
  • Supported by:
    National Natural Science Foundation of China(21575127); Natural Science Foundation of Zhejiang Province(LY19B050004)

电子鼻结合人工智能对呼出气进行检测、分析和识别已成为非侵入性医疗检测领域的研究热点。然而,目前已报道的气体传感材料尚不能同时满足高灵敏度、高选择性和稳定的室温检测,阻碍了气体传感器在医疗健康领域的应用及发展,寻找合适的传感材料具有重要的意义和挑战。新型二维层状纳米材料MXenes具有种类多、比表面积大、导电性能强、表面含有丰富的官能团以及能带宽度可调等优异性能,是高灵敏、低能耗气体传感器的明星候选材料。本综述针对MXenes基材料的特殊结构,总结梳理了MXenes基材料在气体传感中的最新研究成果,聚焦于MXenes材料的气体传感机理和改性方法,对MXenes材料用于气体传感依然存在的问题和挑战进行深入探讨。

关键词： MXenes, 气体传感, 气体吸附, 气敏机理

In order to detect, analyze, and identify exhaled gas, electronic-nose combined with artificial intelligence has become a hot spot in the field of non-invasive medical detection. However, gas sensing materials cannot meet the requirements of high sensitivity as well as high selectivity at room temperature, which seriously hinders the application of gas sensors in the field of health care. It is still challenging to find suitable materials for the electronic-nose. With many unique properties: a wide variety, large specific surface area, strong electrical conductivity, rich functional groups on the surface, and adjustable bandwidth, novel two-dimensional MXenes material has become a star candidate for the gas sensor of highly sensitive and low energy consumption. In this review, we summarize the latest research achievements of MXenes based materials with the special structure in gas sensing, focus on the gas sensing mechanism and modification methods, and probe into the problems and challenges still existing in the application of MXenes materials in gas sensing.

Contents

1 Introduction

2 Synthesis of MXenes

3 Structure and properties of MXenes

3.1 Structure of MXenes

3.2 MXenes electronic characteristics for gas sensing

4 Application of MXenes in gas sensing

4.1 Surface adsorption calculation of MXenes

4.2 Gas sensing performance of MXenes

4.3 Gas sensing mechanism of MXenes

5 Conclusion and outlook

Key words: MXenes, gas sensor, gas adsorption, gas sensing mechanism
()
图1 MXenes的晶体结构示意图和电子显微镜图像;(a)由MAX相到MXenes演变的示意图;(b~d) Ti2CTx、Ti3C2Tx、Ta4C3Tx的SEM图像[49]
Fig.1 Schematic crystal structures and electron microscopy images for MXenes.(a) Schematic illustrating evolution from MAX phases to MXenes;(b~d) SEM images of Ti2CTx, Ti3C2Tx and Ta4C3Tx[49]
表1 部分基于HF溶液刻蚀的MXenes 的制备反应条件
Table 1 The preparation reaction conditions of HF etched MXenes were partly based on HF etched MXenes
Precursor type Composition Etching method MXene ref
M2AX
211 		Ti2AlC 10% conc.-10 h-RT Ti2CTx 49
V2AlC 50% conc.-90 h-RT V2CTx 53
Nb2AlC 50% conc.-90 h-RT Nb2CTx 53
M3AX2
312 		Ti3AlC2 50% conc.-2 h-RT Ti3C2Tx 48
Ti3SiC2 HF 30% conc. + H2O2 35% conc.-45 h-40 ℃ Ti3C2Tx 62
Ti3AlCN 30% conc.-18 h-RT Ti3CNTx 49
M4AX3
413 		V4AlC3 40% conc.-165 h-RT V4C3Tx 54
Nb4AlC3 49% conc.-140 h-RT Nb4C3Tx 55
Ta4AlC3 50% conc.-72 h-RT Ta4C3Tx 49
图2 (a) M3X2,(b) M4X3,(c) M'2M″X2,(d) M'2M″2X3 MXenes的侧视图,其中M、M'、M″表示过渡金属,X表示C或N[71]
Fig.2 Side views of pristine(a) M3X2,(b) M4X3,(c) M'2M″X2, and(d) M'2M″2X3 MXenes, where M, M', and M″ denote transition metals, and X represents C or N[71]
表2 部分MXenes的禁带宽度
Table 2 Bandgap width for some MXenes
MXene Bandgap(eV) ref
Hf3C2O2 0.16 77
Ti2CO2 0.24 78
Sc2T2(OH)2 0.45 78
Cr2TiC2(OH)2 0.84 79
Zr2CO2 0.88 78
Hf2CO2 1.0 78
Sc2T2F2 1.03 78
Cr2TiC2F2 1.35 79
Cr2C(OH)2 1.43 80
Sc2T2O2 1.8 78
Cr2CF2 3.49 80
图3 (a)不同气体在Ti2CO2 MXene上的吸附位点[81];(b)电荷密度分布图[81];(c)利用吸附的NH3和CO2气体分子预测的Ti2CO2的I-V特性[81];(d) 利用吸附的SO2气体分子预测的Sc2CO2的I-V特性[83]
Fig.3 (a) Adsorption sites of different gases on Ti2CO2 MXene[81];(b) charge adsorbed density distribution[81];(c) predicted I-V characteristics of Ti2CO2 with NH3 and CO2 molecules[81];(d) predicted I-V characteristics of Sc2CO2 with SO2 molecules[83]
图4 (a)由Ti3C2Tx滴铸在叉型电极上制成的气体传感器[88];(b)传感器暴露于100 ppm丙酮、乙醇、氨和丙醛时的最大信噪比值[89];(c)室温(25 ℃)下,100 ppm的丙酮、乙醇、氨、丙醛、NO2、SO2和10 000 ppm CO2时的响应值[89];(d)暴露于ppb浓度范围(50~1000 ppb)的丙酮、乙醇和氨气时,响应值随时间的变化图[89]
Fig.4 (a) A gas sensor made from Ti3C2Tx drop-cast on an interdigitated circuit[88];(b) Maximal SNR values of sensors upon exposure to 100 ppm of acetone, ethanol, ammonia, and propanal[89];(c) Maximal resistance change upon exposure to 100 ppm of acetone, ethanol, ammonia, propanal, NO2, SO2, and 10 000 ppm of CO2 at room temperature(25 ℃)[89];(d) Resistance variation versus time upon exposure to highly diluted acetone(top), ethanol(middle), and ammonia(bottom) in ppb concentration range(50~1000 ppb)[89]
表3 MXene基气体传感器的气体传感性能
Table 3 Gas sensing performance of MXene-based gas sensor
Material Gas species LOD Response
((Rg-Ra/Ra)% 		Temperature ref
Ti3C2Tx MXene ammonia 100 ppb 0.1% RT 89
ethanol 100 ppb 0.25%
acetone 50 ppb 0.15%
3D Ti3C2Tx MXene acetone 50 ppb 0.08% RT 97
V2CTx MXene hydrogen 2 ppm 0.04% RT 90
TiO2/Ti3C2Tx ammonia 0.5 ppm 1% 25 ℃ 93
Single-Layer Ti3C2Tx MXene(NaF +HCl etched) ammonia 10 ppm 0.8% 25 ℃ 99
W18O49/Ti3C2Tx acetone 170 ppb 1.6(Ra/Rg) 300 ℃ 92
Alkalized organ-like Ti3C2Tx MXene ammonia 10 ppm — RT 100
V4C3Tx MXene acetone 1 ppm — 25 ℃ 91
Ti3C2Tx/WSe2 hybrids
(n-type sensing behavior) 		ethanol 1 ppm — RT 94
Fe2(MoO4)3/MXene composite n-butanol 5 ppm — 120 ℃ 101
图5 (a) Ti3C2Tx和Ti3C2Tx/WSe2气体传感器对1~40 ppm乙醇的实时传感响应[94];(b) Ti3C2Tx/WSe2异质结构的传感响应机理[94];(c)部分氧化的MXenes薄膜的多传感器阵列芯片[95];(d)部分氧化的MXenes传感器的线性判别分析图[95]
Fig.5 (a) Real-time sensing response of Ti3C2Tx and Ti3C2Tx/WSe2 gas sensors upon ethanol exposure with concentrations ranging from 1 to 40 ppm[94];(b) Enhanced sensing mechanism of Ti3C2Tx/WSe2 heterostructure[94];(c) A multielectrode chip with a film of partially oxidized MXenes flakes prepared by drop-casting[95];(d) LDA diagram of partially oxidized MXenes sensor[95]
图6 (a) MXene/GO纤维纺丝工艺示意图;(b)室温下MXene/rGO在纤维循环弯曲过程中对100 ppm NH3测试的电阻变化;(c)将MXene/rGO气体传感器编织在实验室外套中,并连接到万用表上;(d) 在实验室外套上的MXene/rGO传感器对100 ppm NH3实时响应图[98]
Fig.6 (a) Schematic illustration of the spinning process for MXene/GO hybrid fiber;(b) The resistance change of MXene/rGO hybrid fiber exposed to 100 ppm of NH3 at room temperature during fiber cyclic bending;(c) MXene/rGO hybrid fibers were woven in a lab coat and connected to a multimeter;(d) Gas response of 100 ppm of NH3 molecules in MXene/rGO hybrid fibers woven into a lab coat[98]
图7 (a)丙酮与氨在Ti3C2(OH)2、Ti3C2O2、Ti3C2F2、石墨烯、MoS2、BP上的最低结合能[89];(b) Ti3C2Tx经过0.1%的乙醇吹扫70 min及N2吹扫120 min吸附的乙醇被脱附带走后(002)的峰位移[106]
Fig.7 (a) Minimum binding energies of acetone and ammonia on Ti3C2(OH)2, Ti3C2O2, Ti3C2F2, graphene, MoS2, and BP[89];(b) The(002) peak shift of Ti3C2Tx film during introduction of ethanol(0.1%) for 70 min, followed by N2 purging for 120 min to purge out target gases[106]
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