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Preparation of NiO two-dimensional grainy films and their high-performance gas sensors for ammonia detection.

Wang J, Yang P, Wei X, Zhou Z - Nanoscale Res Lett (2015)

Bottom Line: The morphology and structure analysis of gas sensing materials indicated that the as-fabricated NiO films was uniform and highly ordered porous structure on substrates, which composed of small size particles with diameters ranging from 8 to 30 nm.In the gas sensing performance tests, we found that the excellent electron transport and interconnection properties of sensing films improved the stability and recovery performance of sensors, and porous surface structure increased the specific surface area of sensing films leading to fast response and excellent sensitivity for sensors.Meanwhile, this sensors owned outstanding selectivity toward ammonia which could be because NiO-sensing films had higher binding affinity for the electron-donating ammonia.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Xihua University, Chengdu, 610039 People's Republic of China.

ABSTRACT
Semiconductor NiO two-dimensional grainy films on glass substrates are shown to be an ammonia-sensing devices with excellent comprehensive performance, such as the good stability, short response time, outstanding recovery performance, excellent sensitivity, and selectivity. The morphology and structure analysis of gas sensing materials indicated that the as-fabricated NiO films was uniform and highly ordered porous structure on substrates, which composed of small size particles with diameters ranging from 8 to 30 nm. The shells of these particles were ultrathin amorphous NiO plates, and the core of each particle was face-centered cubic single crystal structure. In the gas sensing performance tests, we found that the excellent electron transport and interconnection properties of sensing films improved the stability and recovery performance of sensors, and porous surface structure increased the specific surface area of sensing films leading to fast response and excellent sensitivity for sensors. Meanwhile, this sensors owned outstanding selectivity toward ammonia which could be because NiO-sensing films had higher binding affinity for the electron-donating ammonia.

No MeSH data available.


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XRD and EDS analysis of NiO film. (A) XRD pattern of NiO film. (B) EDS analysis confirming that the as-prepared films are composed of only Ni and O elements. (C) EDS analysis at two different detection points of NiO film.
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Fig3: XRD and EDS analysis of NiO film. (A) XRD pattern of NiO film. (B) EDS analysis confirming that the as-prepared films are composed of only Ni and O elements. (C) EDS analysis at two different detection points of NiO film.

Mentions: Figure 3A shows the X-ray diffraction patterns of the as-fabricated films on the glass substrates. From the literatures (Joint Committee on Powder Diffraction Standards (JCPDS) card No. 47-1049), all the diffraction peaks of the films match well with the NiO face-centered cubic (fcc) structure. The peaks at scattering angles (two theta) of 37.48°, 43.47°, 62.97°, 75.62°, and 79.61° correspond to crystal planes of (111), (200), (220), (311), and (222) of crystalline NiO, respectively. From this XRD patterns, no other impurity peaks, such as nickel or nickel hydroxide, were detected, indicating that no other products existed in as-fabricated NiO films. EDS analysis (Figure 3B) of NiO film only revealed the peaks of Ni and O, and a similar atomic percentage of Ni and O was observed at two different detection points (Figure 3C), which further confirms that the as-synthesized NiO film are of high purity. In order to better understand the internal microstructure of the small size particle-composed NiO film in more detail, further transmission electron microscopy (TEM) observation is shown in Figure 4A, which shows that the shells of these particle was composed of many ultrathin plates. And then, we perform HRTEM characterization, as shown in Figure 4B, the fuzzier image (i.e., no any lattice fringes) which illustrates that these ultrathin plates were amorphous NiO structures. In the HRTEM image of the core of particle (Figure 4C), the clear lattice fringes indicate that the small size particle-composed NiO film is single crystal structure, and no visible line or planar defects imply the high crystallinity. This crystal is imaged to have nearly parallel lines, which are atomic planes separated via about 0.21 and 0.24 nm in Figure 4C, corresponding to both the {200} planes and the {111} planes of fcc NiO crystal, respectively.Figure 3


Preparation of NiO two-dimensional grainy films and their high-performance gas sensors for ammonia detection.

Wang J, Yang P, Wei X, Zhou Z - Nanoscale Res Lett (2015)

XRD and EDS analysis of NiO film. (A) XRD pattern of NiO film. (B) EDS analysis confirming that the as-prepared films are composed of only Ni and O elements. (C) EDS analysis at two different detection points of NiO film.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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Fig3: XRD and EDS analysis of NiO film. (A) XRD pattern of NiO film. (B) EDS analysis confirming that the as-prepared films are composed of only Ni and O elements. (C) EDS analysis at two different detection points of NiO film.
Mentions: Figure 3A shows the X-ray diffraction patterns of the as-fabricated films on the glass substrates. From the literatures (Joint Committee on Powder Diffraction Standards (JCPDS) card No. 47-1049), all the diffraction peaks of the films match well with the NiO face-centered cubic (fcc) structure. The peaks at scattering angles (two theta) of 37.48°, 43.47°, 62.97°, 75.62°, and 79.61° correspond to crystal planes of (111), (200), (220), (311), and (222) of crystalline NiO, respectively. From this XRD patterns, no other impurity peaks, such as nickel or nickel hydroxide, were detected, indicating that no other products existed in as-fabricated NiO films. EDS analysis (Figure 3B) of NiO film only revealed the peaks of Ni and O, and a similar atomic percentage of Ni and O was observed at two different detection points (Figure 3C), which further confirms that the as-synthesized NiO film are of high purity. In order to better understand the internal microstructure of the small size particle-composed NiO film in more detail, further transmission electron microscopy (TEM) observation is shown in Figure 4A, which shows that the shells of these particle was composed of many ultrathin plates. And then, we perform HRTEM characterization, as shown in Figure 4B, the fuzzier image (i.e., no any lattice fringes) which illustrates that these ultrathin plates were amorphous NiO structures. In the HRTEM image of the core of particle (Figure 4C), the clear lattice fringes indicate that the small size particle-composed NiO film is single crystal structure, and no visible line or planar defects imply the high crystallinity. This crystal is imaged to have nearly parallel lines, which are atomic planes separated via about 0.21 and 0.24 nm in Figure 4C, corresponding to both the {200} planes and the {111} planes of fcc NiO crystal, respectively.Figure 3

Bottom Line: The morphology and structure analysis of gas sensing materials indicated that the as-fabricated NiO films was uniform and highly ordered porous structure on substrates, which composed of small size particles with diameters ranging from 8 to 30 nm.In the gas sensing performance tests, we found that the excellent electron transport and interconnection properties of sensing films improved the stability and recovery performance of sensors, and porous surface structure increased the specific surface area of sensing films leading to fast response and excellent sensitivity for sensors.Meanwhile, this sensors owned outstanding selectivity toward ammonia which could be because NiO-sensing films had higher binding affinity for the electron-donating ammonia.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Xihua University, Chengdu, 610039 People's Republic of China.

ABSTRACT
Semiconductor NiO two-dimensional grainy films on glass substrates are shown to be an ammonia-sensing devices with excellent comprehensive performance, such as the good stability, short response time, outstanding recovery performance, excellent sensitivity, and selectivity. The morphology and structure analysis of gas sensing materials indicated that the as-fabricated NiO films was uniform and highly ordered porous structure on substrates, which composed of small size particles with diameters ranging from 8 to 30 nm. The shells of these particles were ultrathin amorphous NiO plates, and the core of each particle was face-centered cubic single crystal structure. In the gas sensing performance tests, we found that the excellent electron transport and interconnection properties of sensing films improved the stability and recovery performance of sensors, and porous surface structure increased the specific surface area of sensing films leading to fast response and excellent sensitivity for sensors. Meanwhile, this sensors owned outstanding selectivity toward ammonia which could be because NiO-sensing films had higher binding affinity for the electron-donating ammonia.

No MeSH data available.


Related in: MedlinePlus