Preparation of nano-Pt/ZnO heterostructures and gas sensitive properties

doi:10.16085/j.issn.1000-6613.2022-1976

Abstract

Abstract:

As an important component of volatile organic compounds (VOCs), triethylamine (TEA) can cause serious harm to human body and the environment, and thus the detection of triethylamine is of great significance. In this paper, the semiconductor oxide Pt/ZnO heterostructures were designed and synthesized by hydrothermal method, and their gas sensitive properties were systematically studied. The crystal structure and microstructure of the sample, pore structure, element valence band structure and the molecular structure and surface structure were characterized by using X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) and BET nitrogen adsorption, ultraviolet-visible spectra (UV-vis) and X-ray photoelectron spectroscopy (XPS), respectively. The results showed that the morphology existed in the form of irregular nanoparticles and the pore size distribution was mainly about 3.5nm, which belonged to the mesoporous structure. Gas sensing studies found that the optimal working temperature of Pt/ZnO nanoparticles continued to increase in the studied range, and thus the doping of Pt at the optimal working temperature of ZnO (180℃) was chosen to explore the effect of Pt on the gas-sensitive properties of ZnO. At the optimum operating temperature of ZnO, the sensitivity of Pt/ZnO sample with Pt content of 0.5% to 100μL/L TEA was improved by 66 times compared with ZnO at the optimal working temperature of ZnO, and the adsorption and desorption times were improved by 118s and 19s, respectively. The gas-sensitive mechanism study indicated that the generation of heterojunctions in the composite was an important reason for the improved gas-sensitive performance.

Key words: gas sensor, Pt/ZnO, zinc oxide, triethylamine, gas sensitivity

摘要：

三乙胺（TEA）作为挥发性有机化合物（VOCs）的一种重要组成，会对人体和环境造成严重的危害，因此检测三乙胺具有十分重要的意义。然而目前三乙胺实际检测存在高成本和操作耗时的问题，因此迫切需要一种制备简单以及便于监测和检测三乙胺的方法。本文采用水热法设计合成了半导体氧化物Pt/ZnO异质结构，并对其气敏性能进行了系统研究。用X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、BET氮吸附、紫外-可见光光谱（UV-vis）和X射线光电子能谱（XPS）分别表征了样品的晶体结构和微观形貌、孔结构、能带结构以及分子结构和表面元素价态结构。研究表明，形貌以不规则的纳米颗粒形式存在、孔径分布主要在3.5nm左右，属于介孔结构。气敏研究表明：在研究范围内，纳米Pt/ZnO最佳工作温度持续上升，因此选取在ZnO最佳工作温度下（180℃）去探讨Pt的掺杂对ZnO气敏性能的影响。在ZnO最佳工作温度下，Pt摩尔分数为0.5%的Pt/ZnO样品对100μL/L的TEA的灵敏度相比ZnO提高了66倍，吸附脱附时间分别提高118s和19s。气敏机理研究表明，复合材料中异质结的生成是气敏性能提升的重要原因。

关键词: 气敏材料, Pt/ZnO, 氧化锌, 三乙胺, 灵敏度

CLC Number:

TM23

YANG Bin, WANG Xiaodong, WANG Yan, YI Guiyun, WANG Tielang, SHI Chuang, ZHANG Zhanying. Preparation of nano-Pt/ZnO heterostructures and gas sensitive properties[J]. Chemical Industry and Engineering Progress, 2023, 42(9): 4817-4827.

杨斌, 王晓冬, 王燕, 仪桂云, 王铁狼, 时闯, 张战营. 纳米Pt/ZnO异质结构的制备及其气敏性能[J]. 化工进展, 2023, 42(9): 4817-4827.

Figures/Tables 13

References 37

12	DING Jijun, YANG Mingya, CHEN Haixia, et al. Construction of ZnO/GaN in-plane heterojunction with different contacted modes and vacancy defects for improving magnetic and adsorption properties[J]. Applied Surface Science, 2022, 604: 154500.
13	ZOU Dongna, JAMAL R, ABDIRYIM T, et al. Construction and properties of ZnO/poly(EDOT-pyridine-EDOT) core/shell heterostructure nanoarrays for UV photodetector[J]. Synthetic Metals, 2022, 291: 117192.
14	NAVALE Y H, NAVALE S T, STADLER F J, et al. Enhanced NO₂ sensing aptness of ZnO nanowire/CuO nanoparticle heterostructure-based gas sensors[J]. Ceramics International, 2019, 45(2): 1513-1522.
15	XUAN Jingyue, WANG Li, ZOU Yecheng, et al. Room-temperature gas sensor based on in situ grown, etched and W-doped ZnO nanotubes functionalized with Pt nanoparticles for the detection of low-concentration H₂S[J]. Journal of Alloys and Compounds, 2022, 922: 166158.
16	YANG Youzhi, WU Sini, CAO Yuehong, et al. A highly efficient room-temperature formaldehyde gas sensor based on a Ni-doped ZnO hierarchical porous structure decorated with NiS illuminated by UV light[J]. Journal of Alloys and Compounds, 2022, 920: 165850.
17	WANG Ziyan, YANG Xueli, SUN Caixuan, et al. Excellent acetone sensing performance of Au NPs functionalized Co₃O₄-ZnO nanocomposite[J]. Sensor Review, 2022, 42(6): 638-647.
18	FANG Jian, XUE Jingjing, XIAO Rongpu, et al. Synthesis of Pr-doped ZnO nanospindles by one-pot precipitation as a triethylamine sensor[J]. Journal of Environmental Chemical Engineering, 2022, 10(5): 108334.
19	OOSTHUIZEN D N, MOTAUNG D E, SWART H C. Gas sensors based on CeO₂ nanoparticles prepared by chemical precipitation method and their temperature-dependent selectivity towards H₂S and NO₂ gases[J]. Applied Surface Science, 2020, 505: 144356.
20	BUAPUEAN T, JARUDILOKKUL S. Synthesis of mesoporous Zn-doped TiO₂ nanoparticles by colloidal emulsion aphrons and their use for dye-sensitized solar cells[J]. Russian Journal of Applied Chemistry, 2020, 93(8): 1229-1236.
21	XUE Dongping, WANG Pengtao, ZHANG Zhanying, et al. Enhanced methane sensing property of flower-like SnO₂ doped by Pt nanoparticles: A combined experimental and first-principle study[J]. Sensors and Actuators B: Chemical, 2019, 296: 126710.
22	KIM Hogyoung, JUNG Myeong Jun, CHOI Byung Joon. Barrier height enhancement in Pt/n-Ge Schottky junction with a ZnO interlayer prepared by atomic layer deposition[J]. Journal of the Korean Physical Society, 2022, 81(3): 241-246.
23	ZHANG Saisai, LI Yanwei, SUN Guang, et al. Synthesis of NiO-decorated ZnO porous nanosheets with improved CH₄ sensing performance[J]. Applied Surface Science, 2019, 497: 143811.
24	LIU Yiping, ZHU Liyuan, FENG Pu, et al. Bimetallic AuPt alloy nanoparticles decorated on ZnO nanowires towards efficient and selective H₂S gas sensing[J]. Sensors and Actuators B: Chemical, 2022, 367: 132024.
25	XU Qi, JU Dianxing, ZHANG Zichao, et al. Near room-temperature triethylamine sensor constructed with CuO/ZnO P-N heterostructural nanorods directly on flat electrode[J]. Sensors and Actuators B: Chemical, 2016, 225: 16-23.
26	JU Dianxing, XU Hongyan, QIU Zhiwen, et al. Highly sensitive and selective triethylamine-sensing properties of nanosheets directly grown on ceramic tube by forming NiO/ZnO PN heterojunction[J]. Sensors and Actuators B: Chemical, 2014, 200: 288-296.
27	MA Qian, FANG Yuan, LIU Yu, et al. Facile synthesis of ZnO morphological evolution with tunable growth habits: Achieving superior gas-sensing properties of hemispherical ZnO/Au heterostructures for triethylamine[J]. Physica E: Low-Dimensional Systems and Nanostructures, 2019, 106: 180-186.
28	SUN Guang, CHEN Honglin, LI Yanwei, et al. Synthesis and triethylamine sensing properties of mesoporous α-Fe₂O₃ microrods[J]. Materials Letters, 2016, 178: 213-216.
29	XU Hongyan, JU Judianxing, LI Wenru, et al. Superior triethylamine-sensing properties based on TiO₂/SnO₂ n-n heterojunction nanosheets directly grown on ceramic tubes[J]. Sensors and Actuators B: Chemical, 2016, 228: 634-642.
30	YANG Xueli, YU Qi, ZHANG Sufang, et al. Highly sensitive and selective triethylamine gas sensor based on porous SnO₂/Zn₂SnO₄ composites[J]. Sensors and Actuators B: Chemical, 2018, 266: 213-220.
31	YANG Hongyan, CHENG Xiaoli, ZHANG Xianfa, et al. A novel sensor for fast detection of triethylamine based on rutile TiO₂ nanorod arrays[J]. Sensors and Actuators B: Chemical, 2014, 205: 322-328.
32	WU Minzi, ZHANG Xianfa, GAO Shan, et al. Construction of monodisperse vanadium pentoxide hollow spheres via a facile route and triethylamine sensing property[J]. CrystEngComm, 2013, 15(46): 10123-10131.
33	LI Wenru, XU Hongyan, ZHAI Ting, et al. Enhanced triethylamine sensing properties by designing Au@SnO₂/MoS₂ nanostructure directly on alumina tubes[J]. Sensors and Actuators B: Chemical, 2017, 253: 97-107.
34	ZHAI Ting, XU Hongyan, LI Wenru, et al. Low-temperature in situ growth of SnO₂ nanosheets and its high triethylamine sensing response by constructing Au-loaded ZnO/SnO₂ heterostructure[J]. Journal of Alloys and Compounds, 2018, 737: 603-612.
35	ZHANG Dongzhi, YANG Zhimin, WU Zhenling, et al. Metal-organic frameworks-derived hollow zinc oxide/cobalt oxide nanoheterostructure for highly sensitive acetone sensing[J]. Sensors and Actuators B: Chemical, 2019, 283: 42-51.
1	DAI Hongbin, HUANG Guangqiu, WANG Jingjing, et al. Regional VOCs gathering situation intelligent sensing method based on spatial-temporal feature selection[J]. Atmosphere, 2022, 13(3): 483.
2	GAO Shang, ZHAO Yuli, WANG Wei, et al. Au/CuO/Cu₂O heterostructures for conductometric triethylamine gas sensing[J]. Sensors and Actuators B: Chemical, 2022, 371: 132515.
3	CAI Liuxin, CHEN Li, SUN Xiqian, et al. Ultra-sensitive triethylamine gas sensors based on polyoxometalate-assisted synthesis of ZnWO₄/ZnO hetero-structured nanofibers[J]. Sensors and Actuators B: Chemical, 2022, 370: 132422.
4	GUO Jia, LI Hang, MA Qian, et al. Surface oxygen vacancies actuated MoO₃/CuMoO₄ self-assembled microspheres for highly selective triethylamine detection[J]. Sensors and Actuators B: Chemical, 2022, 369: 132256.
5	LI Hang, ZHANG Qi, GUO Jia, et al. In-situ growth of hierarchical SnO₂/In₂O₃ heterostructures with multiple effective n-n heterojunctions for superior triethylamine-sensing performances[J]. Sensors and Actuators B: Chemical, 2022, 369: 132377.
6	ZHANG Yueying, MA Ce, YANG Xinyu, et al. NASICON-based gas sensor utilizing MMnO₃ (M: Gd, Sm, La) sensing electrode for triethylamine detection[J]. Sensors and Actuators B: Chemical, 2019, 295: 56-64.
7	LI Guodong, SHEN Yanbai, ZHAO Sikai, et al. Novel sensitizer Au _x Sn modify rGO-SnO₂ nanocomposites for enhancing detection of sub-ppm H₂ [J]. Sensors and Actuators B: Chemical, 2022, 373: 132656.
8	TIAN Hailin, FAN Huiqing, MA Jiangwei, et al. Pt-decorated zinc oxide nanorod arrays with graphitic carbon nitride nanosheets for highly efficient dual-functional gas sensing[J]. Journal of Hazardous Materials, 2018, 341: 102-111.
9	DING Jijun, DAI Hangfei, CHEN Haixia, et al. Highly sensitive ethylene glycol gas sensor based on ZnO/rGO nanosheets[J]. Sensors and Actuators B: Chemical, 2022, 372: 132655.
10	SUN Lili, GUO Yun, LIU Yanchao, et al. Construction of hierarchical tourmaline@ZnO/MWCNT micro-nanostructured composite and its conductometric gas sensibility for n-butanol detection[J]. Sensors and Actuators B: Chemical, 2022, 371: 132533.
11	HU Jingjie, YUAN Qiming, ZHANG Cheng, et al. A facile cotton biotemplate to fabricate porous ZnFe₂O₄ sheets for acetone gas sensing application[J]. Sensors and Actuators B: Chemical, 2022, 371: 132587.
36	SIL I, CHAKRABORTY B, DUTTA K, et al. Capacitive mode vapor sensing phenomenon in ZnO homojunction: An insight through space charge model and electrical equivalent circuit[J]. IEEE Sensors Journal, 2022, 22(10): 9483-9490.
37	WANG Yan, MENG Xiaoning, YAO Mengxia, et al. Enhanced CH₄ sensing properties of Pd modified ZnO nanosheets[J]. Ceramics International, 2019, 45(10): 13150-13157.

样品	晶粒尺寸/nm
ZnO	30.520
Pt/ZnO-2	28.913

样品	晶粒尺寸/nm
ZnO	30.520
Pt/ZnO-2	28.913

样品	晶格氧/%	空位氧/%	化学吸附氧/%
ZnO	44.98	40.66	14.36
Pt/ZnO-2	39.49	39.14	21.37

样品	晶格氧/%	空位氧/%	化学吸附氧/%
ZnO	44.98	40.66	14.36
Pt/ZnO-2	39.49	39.14	21.37

材料	最佳工作温度 /℃	浓度 /μL·L^-1	响应值	参考文献
NiO-ZnO纳米片	320	100	300	[26]
Pr/ZnO纳米棒	200	50	158	[18]
Au/ZnO半球	260	100	104.8	[27]
α-Fe₂O₃微球	275	100	11.8	[28]
TiO₂-SnO₂纳米片	260	100	52.3	[29]
SnO₂-Zn₂SnO₄纳米球	250	100	48	[30]
TiO₂纳米棒	290	100	14.2	[31]
V₂O₅空心球	370	100	7.2	[32]
Au@SnO₂/MoS₂	300	100	96	[33]
Au@ZnO/SnO₂	300	100	115	[34]
Pt/ZnO-2	180	100	521.7	本研究