Humidity is a critical environmental parameter for several production processes and its control/monitoring is of great importance in maintaining the quality of goods and products. In this context, metallic oxide ceram...Humidity is a critical environmental parameter for several production processes and its control/monitoring is of great importance in maintaining the quality of goods and products. In this context, metallic oxide ceramic nanostructures are materials of great technological interest in the fabrication of moisture sensors because they have good chemical/structural stability and high surface area/volume ratio. The electrical response of these sensors relates to the chemisorbed and physisorbed layers of water molecules on the surface of the ceramic particles and to the capillary condensation of water in the microscopic pores between the particles. Based on these aspects, this work presents the fundamentals, electrical/electronic properties, influence of dopants, novel preparation procedure by electrospinning and perspectives of application of TiO2:WO3 metal oxide heteronanostructures as humidity sensors.展开更多
Relative humidity(RH) is a critical environmental variable for transportation and storage of products and for the quality guarantee of several other production processes and services. Heterogeneous structures prepared...Relative humidity(RH) is a critical environmental variable for transportation and storage of products and for the quality guarantee of several other production processes and services. Heterogeneous structures prepared from the selective semiconductor oxides may improve the sensitivity to humidity due to the better electronic and surface properties, when compared to pristine oxides. This work shows an alternative fabrication route for producing titanium dioxide/tungsten trioxide(TiO2/WO3) heterogeneous structures(by electrospinning and sintering) for potential application on the RH detection. The microstructural properties of the materials were analyzed by scanning electron microscopy(SEM), energy dispersive X-ray analysis(EDS), X-ray diffraction, and Raman spectroscopy. The electrical characterization of the structures was performed by electrical impedance spectroscopy in RH range of 10%–100%. Results indicated a p-to n-type conduction transition at around 30%–40% RH for all tested settings. The analysis of the impedance signature to humidity showed that the amount of fiber layers on the electrode and working temperature are important parameters to improve the humidity sensing of the TiO2/WO3 systems.展开更多
基金The authors acknowledge the financial support from Bahia State Research Foundation(FAPESB,Project 1252/2018).
文摘Humidity is a critical environmental parameter for several production processes and its control/monitoring is of great importance in maintaining the quality of goods and products. In this context, metallic oxide ceramic nanostructures are materials of great technological interest in the fabrication of moisture sensors because they have good chemical/structural stability and high surface area/volume ratio. The electrical response of these sensors relates to the chemisorbed and physisorbed layers of water molecules on the surface of the ceramic particles and to the capillary condensation of water in the microscopic pores between the particles. Based on these aspects, this work presents the fundamentals, electrical/electronic properties, influence of dopants, novel preparation procedure by electrospinning and perspectives of application of TiO2:WO3 metal oxide heteronanostructures as humidity sensors.
基金the financial support from National Council for Scientific and Technological Development(CNPq Brazil,Project 202451/2015-1)Bahia State Research Foundation(FAPESB,Project 1252/2018)
文摘Relative humidity(RH) is a critical environmental variable for transportation and storage of products and for the quality guarantee of several other production processes and services. Heterogeneous structures prepared from the selective semiconductor oxides may improve the sensitivity to humidity due to the better electronic and surface properties, when compared to pristine oxides. This work shows an alternative fabrication route for producing titanium dioxide/tungsten trioxide(TiO2/WO3) heterogeneous structures(by electrospinning and sintering) for potential application on the RH detection. The microstructural properties of the materials were analyzed by scanning electron microscopy(SEM), energy dispersive X-ray analysis(EDS), X-ray diffraction, and Raman spectroscopy. The electrical characterization of the structures was performed by electrical impedance spectroscopy in RH range of 10%–100%. Results indicated a p-to n-type conduction transition at around 30%–40% RH for all tested settings. The analysis of the impedance signature to humidity showed that the amount of fiber layers on the electrode and working temperature are important parameters to improve the humidity sensing of the TiO2/WO3 systems.
