Study on gas sensing mechanism in p-CuO/n-ZnO heterojunction sensor

Mariammal, R. N.; Ramachandran, K.

doi:10.1016/j.materresbull.2017.12.046

Cited by 39 publications

(4 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The appeared peak at ∼505 cm −1 is matched for both oxides, being able to belong to any of the two oxides. The observed shift is attributed to the changes in size, shape and state of aggregation of the nanoparticles forming the α-Fe 2 O 3 /CuO heterostructure, which affect the FTIR modes [59].…”

Section: Resultsmentioning

confidence: 99%

Fabrication and characterization of α-Fe₂O₃/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance

Pastrana

Zamora

Wang

et al. 2019

Adv. Nat. Sci: Nanosci. Nanotechnol.

View full text Add to dashboard Cite

In this work, a heterostructure-based thin film combining n-type α-Fe 2 O 3 with p-type CuO was fabricated by a dip-coating technique, the heterostructure was fabricated on fluorine-doped tin oxide (FTO) glass substrate. The synthesised sample was characterised by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectroscopy (UV-vis). XRD, FTIR, Raman, and XPS reveal the successful synthesis of α-Fe 2 O 3 /CuO composite and confirm the existence of hematite (α-Fe 2 O 3 ) and tenorite (CuO) phases in the heterostructure. AFM reveals the growth of CuO crystals in the heterostructure with superficial intermingled pointy shape, different than its pristine topography. The SEM images show that the α-Fe 2 O 3 /CuO heterostructure thickness was ∼880 nm. The optical band gap energies estimated from the optical transmittance spectra were 2.15, 2.00 and 1.77 eV for α-Fe 2 O 3 , CuO and α-Fe 2 O 3 /CuO heterostructure, respectively. The photoelectrochemical photocurrent effects (J-V curves) for the heterostructure were measured in a three-electrode cell in the dark and under illumination. The photocurrent density for heterostructure was improved mainly attributed to the enhanced visible light absorption, efficient charge carriers separation and transfer between α-Fe 2 O 3 and CuO.

show abstract

Section: Resultsmentioning

confidence: 99%

Fabrication and characterization of α-Fe₂O₃/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance

Pastrana

Zamora

Wang

et al. 2019

Adv. Nat. Sci: Nanosci. Nanotechnol.

View full text Add to dashboard Cite

show abstract

“…The absorption peak at 3200–3600 cm −1 corresponds to the stretching vibrational bonds of the hydroxyl group (OH − ) in the samples [ 35 ], and its intensity increases with the increase of CuO content. The peak at around 2341.4 cm −1 is caused by the CO 2 molecule in the air, and the peak at 1640.8 cm −1 results in C–H and C=C [ 38 , 39 ]. The peaks at 1554.6, 1548.5, 1547.7, and 1546.7 cm −1 correspond to the in-plane bending vibrations of the amino group (N–H) [ 40 ], which are increased significantly with the increase in CuO content.…”

Section: Resultsmentioning

confidence: 99%

Study of Highly Sensitive Formaldehyde Sensors Based on ZnO/CuO Heterostructure via the Sol-Gel Method

Liu

Chen

Zhang

2021

Sensors

View full text Add to dashboard Cite

Formaldehyde (HCHO) gas sensors with high performance based on the ZnO/CuO heterostructure (ZC) were designed, and the sensing mechanism was explored. FTIR results show that more OH− and N–H groups appeared on the surface of ZC with an increase in Cu content. XPS results show that ZC has more free oxygen radicals (O*) on its surface compared with ZnO, which will react with more absorbed HCHO molecules to form CO2, H2O and, electrons, accelerating the oxidation-reduction reaction to enhance the sensitivity of the ZC sensor. Furthermore, electrons move from ZnO to CuO in the ZC heterostructure due to the higher Fermi level of ZnO, and holes move from CuO to ZnO until the Fermi level reaches an equilibrium, which means the ZC heterostructure facilitates more free electrons existing on the surface of ZC. Sensing tests show that ZC has a low detection limit (0.079 ppm), a fast response/recovery time (1.78/2.90 s), and excellent selectivity and sensitivity for HCHO detection at room temperature. In addition, ambient humidity has little effect on the ZC gas sensor. All results indicate that the performance of the ZnO sensor for HCHO detection can be improved effectively by ZC heterojunction.

show abstract

“…Various parameters elaborated in previous reported literature that can affect the efficiency of the gas sensors. [103][104][105]…”

Section: Metal Oxide-based 2d Nanomaterials (Mo-2d)mentioning

confidence: 99%

Two‐Dimensional Nanomaterials for the Development of Efficient Gas Sensors: Recent Advances, Challenges, and Future Perspectives

Kiani

Rehman

Tian

et al. 2021

Adv Materials Technologies

View full text Add to dashboard Cite

The advancement of nanotechnology has produced a huge potential to prepare highly sensitive and portable sensors with low cost and low energy consumption. Here, a comprehensive review of the recent development of two‐dimensional nanomaterials for gas sensors is presented. Emerging kinds of two‐dimensional nanomaterials‐based sensors with high surface‐to‐volume ratio and porous nanostructures are considered superior for the adsorption of gas molecules, for various gases have been discussed in this review. In addition, strategies that can enhance sensor performance by nanomaterials design and synthesis are also discussed and elaborated for the novel two‐dimensional nanomaterials to the development of sensing technology. Finally, the current challenges have been summarized and future perspectives for the development of gas sensors are also suggested.

show abstract

Study on gas sensing mechanism in p-CuO/n-ZnO heterojunction sensor

Cited by 39 publications

References 28 publications

Fabrication and characterization of α-Fe₂O₃/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance

Fabrication and characterization of α-Fe₂O₃/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance

Study of Highly Sensitive Formaldehyde Sensors Based on ZnO/CuO Heterostructure via the Sol-Gel Method

Two‐Dimensional Nanomaterials for the Development of Efficient Gas Sensors: Recent Advances, Challenges, and Future Perspectives

Contact Info

Product

Resources

About

Study on gas sensing mechanism in p-CuO/n-ZnO heterojunction sensor

Cited by 39 publications

References 28 publications

Fabrication and characterization of α-Fe2O3/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance

Fabrication and characterization of α-Fe2O3/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance

Study of Highly Sensitive Formaldehyde Sensors Based on ZnO/CuO Heterostructure via the Sol-Gel Method

Two‐Dimensional Nanomaterials for the Development of Efficient Gas Sensors: Recent Advances, Challenges, and Future Perspectives

Contact Info

Product

Resources

About

Fabrication and characterization of α-Fe₂O₃/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance

Fabrication and characterization of α-Fe₂O₃/CuO heterostructure thin films via dip-coating technique for improved photoelectrochemical performance