Nanostructured Cobalt Doped Barium Strontium Titanate Thin Films with Potential in CO2 Detection

Abstract

In this work, (Ba0.75Sr0.25) (Ti0.95Co0.05) O3 perovskite nanostructured material, denoted subsequently as Co-doped BaSrTiO3, was synthesized in a one-step process in hydrothermal conditions. The obtained powder was heat-treated at 800 °C and 1000 °C, respectively, in order to study nanostructured powder behavior during thermal treatment. The Co-doped BaSrTiO3 powder was pressed into pellets of 5.08 cm (2 inches) then used for thin film deposition onto commercial Al2O3 substrates by RF sputtering method. The microstructural, thermal, and gas sensing properties were investigated. The electrical and thermodynamic characterization allowed the evaluation of thermodynamic stability and the correlation of structural features with the sensing properties revealed under real operating conditions. The sensing behavior with respect to the temperature range between 23 and 400 °C, for a fixed CO2 concentration of 3000 ppm, highlighted specific differences between Co-doped BaSrTiO3 treated at 800 °C compared to that treated at 1000 °C. The influence of the relative humidity level on the CO2 concentrations and the other potential interfering gases was also analyzed. Two possible mechanisms for CO2 interaction were then proposed. The simple and low-cost technology, together with the high sensitivity when operating at room temperature corresponding to low power consumption, suggests that Co-doped BaSrTiO3 has a good potential for use in developing portable CO2 detectors.

Synthesis and photoelectrochemical performance of Co doped SrTiO3 nanostructures photoanode

“…The crystallite size of pure SrTiO 3 perovskite and cobalt doped nano powder SrTiO 3 have obtained from XRD analysis and drawn in Figure 2. The major peaks has been displayed at 22.6, 32.1, 39.6, 46.2, 57.3, and 67.3°, which has been assigned to (100), (110), (111), (200), (211), and (220), the peaks are all indexed to perovskite structure of SrTiO 3 which agree well with the data for the (JCPDS card No.‐ 893697) 17 . The diffraction peaks can be indexed as cubic SrTiO 3 .…”

“…The final powder was obtained after drying at 80 C for 6 h and its corresponding schematic synthesis process is illustrated in No.-893697). 17 The diffraction peaks can be indexed as cubic SrTiO 3 .…”

Review on Synthesis and Properties of Lithium Lanthanum Titanate

“…In the former class the oxidation state of the A-site cation is 2+ and correspondingly the oxidation state of the B-site cation is 4+. Examples of this class include materials well known materials such as BaTiO 3 , SrTiO 3 , PbTiO 3 and PbVO 3 [38][39][40]. In the latter class, the valence of both A and B cations is 3+.…”

The Heterostructures of CuO and SnOx for NO2 Detection

“…Currently, the most popular resistance sensors are metal oxide semiconductor sensors (MOX) [ 13 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Various metal oxides are used as gas sensors; for example, barium titanate, strontium titanate and barium strontium titanate doped with various elements depending on the doped materials; they behave as p-type or n-type [ 31 , 32 ], n-type including zinc oxide (ZnO) [ 33 , 34 ], tin dioxide (SnO 2 ) [ 35 ], tungsten trioxide (WO 3 ) [ 36 ], indium oxide (In 2 O 3 ), gallium oxide (Ga 2 O 3 ), vanadium oxide (V 2 O 5 ) and iron oxide (Fe 2 O 3 ) and p-type metal oxides such as nickel oxide (NiO), copper oxide (CuO) [ 37 ], cobalt oxide (Co 3 O 4 ), manganese oxide (Mn 3 O 4 ) and chromium oxide (Cr 2 O 3 ) [ 38 , 39 ]. As gas-sensitive materials in gas sensors, heterostructures are also used, such as tin sulfide/tin oxide (SnS 2 /SnO 2 ), tungsten disulfide/titanium dioxide (WS 2 /TiO 2 ), molybdenum disulfide/tin oxide (MoS 2 /SnO 2 ), molybdenum disulfide/zinc oxide (MoS 2 /ZnO), reduced graphene oxide/tin oxide (rGO/SnO 2 ), reduced graphene oxide/carbon dot (rGO/CD), reduced graphene oxide/molybdenum disulfide (rGO/MoS 2 ) [ 40 ], reduced graphene oxide/iron oxide (rGO/F 2 O 3 ) [ 41 ], cobalt tetroxide/titanium dioxide (Co 3 O 4 /TiO 2 ) [ 42 ], zinc oxide/indium oxide (ZnO/In 2 O 3 ), tin oxide/cupric oxide (SnO 2 /CuO), titanium dioxide/vanadium pentoxide (TiO 2 /V 2 O 5 ) [ 30 ], graphene in combination with metal oxides [ 43 ] and many others.…”