Enhanced humidity responsive ultrasonically nebulised V₂O₅ thin films

Abstract

A large surface to volume ratio and easily accessible active reaction sites are key attributes for a good gas sensing material. Herein, we report synthesis, characterisation and humidity sensing properties of phase pure 420 nm thick low temperature (350°C) polycrystalline V 2 O 5 thin films deposited on quartz substrate by ultrasonic nebulized spray pyrolysis of aqueous combustion mixture (UNSPACM). The thin films were characterized by x-ray diffraction, Raman spectroscopy, atomic force microscope, field emission scanning microscope, transmission electron microscope, UV-visible spectroscopy and XPS. The highly porous and nanocrystalline characteristic of V 2 O 5 thin films synthesized by this technique provide large surface to volume ratio and easily accessible active reaction sites making it a prominent material for gas sensing applications. The fabricated humidity sensor based on V 2 O 5 thin films exhibited high sensitivity with good stability and reproducibility at room temperature. The sensor exhibited high sensitivity of 90.8% at 76% RH with response time of 35-60 s and recovery time of 7-54 s. We believe this method provides means for large-scale synthesis of V 2 O 5 thin films for several gas sensing applications. OPEN ACCESS RECEIVED

Influence of Crystalline, Structural, and Electrochemical Properties of Iron Vanadate Nanostructures on Flutamide Detection

“…Also, vanadates have shown reasonable electrocatalytic activity, cost-effective, and are found in abundance . Vanadates have been found in a wide range of applications such as energy-saving and storage applications, , MEMS and microelectronics, lithium batteries, catalytic applications, supercapacitors, water splitting, and sensing applications. − Nevertheless, some improvement in their moderate electrochemical kinetics and catalytic activity is called for. The structural stability and the conductivity of vanadates can be improved by doping with a transition metal to fabricate as transition-metal orthovanadates (TMVO 4 ). , Among various metal vanadates, iron vanadate (FeVO 4 ), a n-type semiconductor, has excellent electrochemical and catalytic properties that can be used for developing sensors .…”

Peculiarities of the Vanadium Oxidation Degree Determination by XPS Method in Nanodispersed Oxide Systems

“…At the same time, we analyzed the literature data on the deposited samples of vanadium oxide, which presents the results of the study by the XPS method. The samples were synthesized by CVD, PVD, and magnetron sputtering, using vanadyl acetylacetonate and the formation nanosized particles or films was confirmed by TEM, AFM, and HRTEM methods [13,16,17,[22][23][24]. The obtained results are presented in Table 3 Table 3 data show that during the synthesis of samples, which leads to the formation of microsized particles of vanadium oxide, the calculation of the vanadium oxidation degree by Eq.…”

“…Vanadium(V) oxide 7.37 [11] 7.48 [13] 8.30 [14] 7.30 [16] 7.20 [17] 7.30 [18] 7.33 [19] 7.35 [20] Vanadium(IV) oxide 7.52 [13] 7.90 [14] 7.20 [17] 7.26 [18] 7.33 [16] 7.40 [19] 7.35 [20] Vanadium(III) oxide 7.44 [15] 7.70 [17] 7.50 [17] 7.30 [18] 7.33 [19] Vanadium(II) oxide 7.35 [18] 7.33 [19] Vanadium(0) oxide 7.80 [17] 7.50 [19] 7.53 [20] structure, which dramatically changes the ratio between surface and particle mass. We analyzed the samples of vanadium oxide by the XPS method, synthesized by us on different carriers and using different synthesis methods, in order to verify this assumption (Table 3).…”

A Review of Nanostructured Resistive-Based Vanadium Oxide Gas Sensors

“…V 2 O 5 is highly abundant in nature, it has low price and has several oxidation states [7,8]. Accordingly, due to its relatively open layered structure and its unique properties, V 2 O 5 has been used in different applications such as water splitting [9], field effect transistors [10,11], supercapacitors [12], IR detectors [13], photodetectors [14], UV sensors [15], optical sensors [16], amprometric gas sensors [17], potentiometric sensors [18] electrochemical sensors [19,20], cataluminescence sensors [21], resistance gas sensors [22,23], gasochromic sensors [24] and humidity sensors [25]. V 2 O 5 with an n-type semiconducting behavior, has a relatively high conductivity (0.5 S•cm −1 ) at room temperature [26].…”