NO gas sensing at room temperature using single titanium oxide nanodot sensors created by atomic force microscopy nanolithography

Abstract

SummaryIn this work, the fabrication of single titanium oxide nanodot (ND) resistive sensors for NO gas sensing at room temperature is reported. Two atomic force microscopy nanolithography methods, nanomachining and nano-oxidation, are employed. A single titanium nanowire (NW) is created first along with contact electrodes and a single titanium oxide ND is subsequently produced in the NW. Gas sensing is realized by the photo-activation and the photo-recovery approaches. It is found that a sensor with a smaller ND has better performance than a larger one. A response of 31%, a response time of 91 s, and a recovery time of 184 s have been achieved at a concentration of 10 ppm for a ND with a size of around 80 nm. The present work demonstrates the potential application of single metal oxide NDs for gas sensing with a performance that is comparable with that of metal oxide nanowire gas sensors.

Advances in designs and mechanisms of semiconducting metal oxide nanostructures for high-precision gas sensors operated at room temperature

“…2. Room temperature gas sensors based on single phase semiconducting metal oxide nanostructures 2.1 N-type semiconducting metal oxide nanostructures and gas sensors N-type SMONs are the most reported sensing materials for RT resistive gas sensors, and they include ZnO, [152][153][154][155][156] SnO 2 , [157][158][159][160] In 2 O 3 , 161 WO 3 , 162 TiO 2 , [163][164][165][166] Fe 2 O 3 , [167][168][169] MoO 3 , 170 174 acetone, 175 alcohol, 106 HCHO, 176 liquefied petroleum gas (LPG), etc. Table 1 summarizes some of the reported RT sensors using the n-type SMONs.…”

A TSV-Structured Room Temperature p-Type TiO2 Nitric Oxide Gas Sensor

“…Moreover, it was found that the average response and recovery time of the TSV-structured TiO 2 NO gas sensor are about 109 and 144 s. The response and recovery time are defined as the time required for a 90% change in the signal. Furthermore, this result indicated that the TSV-structured TiO 2 NO gas sensor had a better response and recovery time than the previous studies [36][37][38][39][40], as shown in Table 1.…”

Current Trends in Nanomaterials for Metal Oxide-Based Conductometric Gas Sensors: Advantages and Limitations. Part 1: 1D and 2D Nanostructures

“…During printing, the metal electrodes are precisely placed on top of the 1D structures. However, all these fabrication techniques are still in a preliminary stage of development, despite some promising results that have recently been reported [254][255][256][257][258][259][260][261]. advantage of this technique is its flexibility due to direct recording capabilities without using any masks [237,240].…”

“…During printing, the metal electrodes are precisely placed on top of the 1D structures. However, all these fabrication techniques are still in a preliminary stage of development, despite some promising results that have recently been reported [ 254 , 255 , 256 , 257 , 258 , 259 , 260 , 261 ].…”