Zinc Titanate Nanoarrays with Superior Optoelectrochemical Properties for Chemical Sensing

Abstract

In this report, the gas sensing performance of zinc titanate (ZnTiO3) nanoarrays (NAs) synthesized by coating hydrothermally formed zinc oxide (ZnO) NAs with TiO2 using low-temperature chemical vapor deposition is presented. By controlling the annealing temperature, diffusion of ZnO into TiO2 forms a mixed oxide of ZnTiO3 NAs. The uniformity and the electrical properties of ZnTiO3 NAs made them ideal for light-activated acetone gas sensing applications for which such materials are not well studied. The acetone sensing performance of the ZnTiO3 NAs is tested by biasing the sensor with voltages from 0.1 to 9 V dc in an amperometric mode. An increase in the applied bias was found to increase the sensitivity of the device toward acetone under photoinduced and nonphotoinduced (dark) conditions. When illuminated with 365 nm UV light, the sensitivity was observed to increase by 3.4 times toward 12.5 ppm acetone at 350 °C with an applied bias of 9 V, as compared to dark conditions. The sensor was also observed to have significantly reduced the adsorption time, desorption time, and limit of detection (LoD) when excited by the light source. For example, LoD of the sensor in the dark and under UV light at 350 °C with a 9 V bias is found to be 80 and 10 ppb, respectively. The described approach also enabled acetone sensing at an operating temperature down to 45 °C with a repeatability of >99% and a LoD of 90 ppb when operated under light, thus indicating that the ZnTiO3 NAs are a promising material for low concentration acetone gas sensing applications.

Inorganic-Diverse Nanostructured Materials for Volatile Organic Compound Sensing

“…Because the Ag-doped ZnO nanoneedles [77] did not display any exceptional response (R a /R g = 30.233; for 200 ppm at 370 • C); therefore, they did not play an important role in volatile acetone detection. Devices with hydrothermally synthesized nanoarrays, such as La-doped SnO 2 , hybrid 1D/2D α-Fe 2 O 3 -SnO 2 , and ZnTiO 3 were engaged in acetone gas estimation [78][79][80]. Wherein, in contrast to other nanoarrays, ZnTiO 3 nanoarrays [80] showed exceptional sensor responses of 78/94 for 12.5 ppm at 45 • C/350 • C with the LODs of 0.09 and 0.01 ppm, correspondingly.…”

“…Devices with hydrothermally synthesized nanoarrays, such as La-doped SnO 2 , hybrid 1D/2D α-Fe 2 O 3 -SnO 2 , and ZnTiO 3 were engaged in acetone gas estimation [78][79][80]. Wherein, in contrast to other nanoarrays, ZnTiO 3 nanoarrays [80] showed exceptional sensor responses of 78/94 for 12.5 ppm at 45 • C/350 • C with the LODs of 0.09 and 0.01 ppm, correspondingly. This work is impressive because its operation at dark and light conditions can be completed with less than 3 min response/recovery time.…”

Synthesis Methods and Applications of Semiconductor Material ZnWO4 with Multifunctions and Multiconstructions

“…[ 154,155 ] It has been widely used to manufacture nanoarrays with high crystallinity. Some scholars [ 156 ] used a low‐temperature CVD method to coat TiO 2 on ZnO nanoarrays to synthesize ZnTiO 3 nanoarrays and used them as gas‐sensing materials. The synthesis process is shown in Figure 19a.…”

“…Reproduced with permission. [ 156 ] Copyright 2019, American Chemical Society. b) Schematic illustration for the synthesis of NiCoP/CNT/CC and CNT@N‐C/CC.…”

Preparation and NH3 Gas-Sensing Properties of Double-Shelled Hollow ZnTiO3 Microrods

“…Yadav et al [25] fabricated a ZnTiO 3 nanopowders film using a physicochemical method for sensing liquefied petroleum gas (LPG) at room temperature. Ippolito et al [26] fabricated an acetone gas sensor that was made of ZnTiO 3 nanoarrays using a hydrothermal method. The limit of detection (LOD) of this sensor under light and at 350 • C was 10 ppb.…”