Nanotubular Cr-doped TiO 2 for use as high-temperature NO 2 gas sensor

Gönüllü, Yakup; Haidry, Azhar Ali; Saruhan, Bilge

doi:10.1016/j.snb.2014.11.065

Cited by 93 publications

(40 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the increasing Cr contents, the diffraction peaks of rutile become obvious. Thus, it can be concluded that Cr ions can promote the transformation of anatase to rutile when annealed at 600 • C. On the basis of the reports (Gonullu et al, 2015), it can be explained by the formation electric stress produced as a result of Cr replacing Ti 4+ in TiO 2 lattice. Having similar ionic radii with Ti 4+ (0.60 Å), Cr 3+ (0.61 Å) can substitute Ti 4+ without any visible deformation.…”

Section: Structural and Morphological Characteristicsmentioning

confidence: 93%

Sol-gel Synthesis of TiO2 With p-Type Response to Hydrogen Gas at Elevated Temperature

Xie

Sun

et al. 2019

Front. Mater.

Self Cite

View full text Add to dashboard Cite

Titanium dioxide is considered as one of the potential candidates for high-temperature gas sensing applications due to its excellent sensitivity and stability. However, its practical use as a gas sensor under elevated conditions is limited on account of its selectivity and insufficient understanding of response conversion from n-to p-type. To this context, the present work is intended to prepare and understand the p-type response of anatase TiO 2 toward H 2 gas (20-1,000 ppm) at elevated temperature (500 • C). Sol-gel route is adopted to facilely synthesize powders containing pure and chromium (1-10 at.%) doped TiO 2 nanoparticles, which are then brushed onto substrates with already patterned inter-digitated platinum electrodes. In this work, even, the undoped TiO 2 samples showed p-type gas sensing response, which then decreased with Cr doping. However, in comparison to previously reported work, the sensing characteristics of all sensors is improved. For instance, 5 at.% Cr-TiO 2 showed high response (147), fast response and recovery (142/123s) time, and good selectivity to hydrogen against monoxide and methane. Despite better response values, the TiO 2 based samples show instability and drift in baseline resistance; such issues were not observed for Cr-doped TiO 2 samples (≥3 at.%). The powders were further analyzed by XRD, SEM, TEM, and XPS to understand the basic characteristics, p-type response and stability. Further, a plausible sensing mechanism is discussed on basis of results obtained from aforementioned techniques.

show abstract

Section: Structural and Morphological Characteristicsmentioning

confidence: 93%

Sol-gel Synthesis of TiO2 With p-Type Response to Hydrogen Gas at Elevated Temperature

Xie

Sun

et al. 2019

Front. Mater.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The sensing properties of the undoped and doped TiO 2 were investigated toward 200 ppm NO 2 and 200 ppm H 2 at 600 • C using synthetic air as carrier gas. This temperature was chosen on the basis of our previous results obtained with undoped and Al-and Cr-doped TiO 2 relying on the fact that undoped TiO 2 is capable of NO 2 -sensing at above 400 • C (Saruhan et al, 2013;Gönüllü et al, 2015). In fact, as the temperature increases, the sensor signal and also the response time decreases.…”

Section: Resultsmentioning

confidence: 99%

“…Some previous studies in our team show how the Al and Cr-addition alters the electron conductivity of TiO 2 from n-to p-type leading to effective gas sensing materials. As far as Cr-doped TiO 2 is concerned, the optimum temperature for sensing properties has been limited with 500 • C while the Al-doped TiO 2 detects NO 2 at 600 • C but the sensitivity is low and the signal converts to p-type at 800 • C (Saruhan et al, 2013;Gönüllü et al, 2015). Several other papers discuss the relation and reasons between the nature of the electronic structure and the sensing characteristics of the oxide materials (Wisitsoraat et al, 2009;Zhaohui et al, 2013;Gönüllü et al, 2015) and report that the enhancement of the sensing performance can directly be controlled by adjustment of the electronic structure to p-type at the semi-conducting oxide sensing layer.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Co3+ Doped TiO2 by Co-precipitation Route and Its Gas Sensing Properties

Fomekong

Saruhan

2019

Front. Mater.

Self Cite

View full text Add to dashboard Cite

Undoped and Co-doped TiO 2 nanoparticles were synthesized by a facile co-precipitation method and calcined at 700 • C. The phase identification carried out by XRD measurements and Raman spectroscopy analysis of calcined powders reveals the formation of mainly anatase phase for undoped TiO 2 , and 0.5 mol.% Co-doped TiO 2 whereas rutile phase for 1 mol.% Co-doped TiO 2 . The sensors prepared with these powders deposited on interdigital (IDE) sensor platforms were tested toward NO 2 and H 2 sensing properties at 600 • C. As the undoped and 0.5% Co-doped TiO 2 reveal n-type behavior, 1% Co-doped TiO 2 shows p-type semi-conductive behavior. One percentage Co-doped TiO 2 exhibits good sensing performance toward NO 2 while the undoped TiO 2 powder yields the best sensor performance toward H 2 at 600 • C. This indicates that the crystal structure of TiO 2 sensing material must be adjusted depending on the nature of target gas. The results indicate that the main factor influencing high temperature gas sensor performance of nanoparticulate TiO 2 is either the alteration of its electronic structure or the type of polymorphs.

show abstract

“…Gönüllü et al [61] studied the impact of doping the surface of TiO 2 nanotubes. TNA for NO 2 detection at high temperature were obtained by anodization.…”

Section: Sensing Performance Of Tio 2 1-d Nanostructuresmentioning

confidence: 99%

Nanostructured TiO2 Layers for Photovoltaic and Gas Sensing Applications

Decroly¹,

Krumpmann²,

Debliquy³

et al. 2016

Green Nanotechnology - Overview and Further Prospects

View full text Add to dashboard Cite

Titanium dioxide (TiO 2 ) has been an important material for decades, combining numerous attractive properties in terms of economy (low price, large availability) or ecology (nontoxic), as well as broad physical and chemical possibilities. In the last few years, the development of nanotechnologies offered new opportunities, not only in an academic perspective but also with a view to many applications with particular reference to the environment. This chapter focuses on the many ways that allow to tailor and organize TiO 2 crystallites at the nanometre scale to make the most of this amazing material in the field of photovoltaics and gas sensing.

show abstract

Nanotubular Cr-doped TiO 2 for use as high-temperature NO 2 gas sensor

Cited by 93 publications

References 44 publications

Sol-gel Synthesis of TiO2 With p-Type Response to Hydrogen Gas at Elevated Temperature

Sol-gel Synthesis of TiO2 With p-Type Response to Hydrogen Gas at Elevated Temperature

Synthesis of Co3+ Doped TiO2 by Co-precipitation Route and Its Gas Sensing Properties

Nanostructured TiO2 Layers for Photovoltaic and Gas Sensing Applications

Contact Info

Product

Resources

About