Vanadium‐Tin Oxide Nanoparticles with Gas‐Sensing and Catalytic Activity

Abstract

Nanopowders of vanadium-tin oxides were prepared by a co-precipitation process and characterized for their bulk structures, chemical state, sensing capability, and surface reactivity. The solid solutions (cassiterite) were evaluated as sensing elements in a carbon monoxide gas sensor and as catalysts for methanol oxidation in a fixed-bed reactor. Sensing and catalytic properties were observed dependent upon doping concentration and oxidation state of vanadia species. The sensor response was favored for lower vanadium loadings (V/Sn = 0.05À0.1), related to the reduced vanadium sites. The catalytic activity for methanol conversion was favored for higher vanadium loadings (V/Sn = 0.15À0.2), related to the oxidized vanadium sites. Results demonstrate that the V-O-Sn structure provides redox activity to facilitate oxygen activation for CO gas-sensing response and promote methanol partial oxidation to formaldehyde. Mechanistic aspects that elucidate the redox pathways are discussed. These oxide nanostructures are promising ceramic materials for use in sensing and catalysis fields involving electron transfer. D. Damjanovic-contributing editorManuscript No. 29386.

Synthesis of novel penta and hexa coordinated monobutyltin(IV) derivatives based on oximes and N-protected amino acids

“…It has been reported that a new dimethyltin(IV) complex was used as a precursor for the preparation of SnO 2 nanoparticles which show photoluminescence (Najafi et al, 2013). SnO 2 nanoparticles exhibit significant industrial applications such as catalyst supports (Jang et al, 2008;Dehbashi et al, 2013;Higuchi et al, 2014;Rabis et al, 2014;Zhao et al, 2014), transparent conducting electrodes (Kleinjan et al, 2008) and gas sensors (Wang et al, 2011;Kim et al, 2012;Xing et al, 2013). Some organotin(IV) compounds are used as PVC stabilizers (Xu et al, 1990), catalysts (Ashfaq et al, 2011;Devendra et al, 2013;Tariq et al, 2013), antioxidants (Jabbar et al, 2012;Sirajuddin et al, 2014), fungicides (Menezes et al, 2005;Singh and Kaushik 2008;Aziz-urRehman et al, 2011;Parrilha et al, 2011;Dias et al, 2012) and as potential antitumor agents (Gleeson et al, 2008;Arjmand et al, 2011;Sun et al, 2011;Verginadis et al, 2011;Khandani et al, 2013;Nath et al, 2013;Carraher and Roner, 2014).…”

Effect of Vanadium on Structure and Morphology of SnO2 Thin Films

“…11 represents the values of the direct energy gap, which was calculated from Equation 5 [25], by plotting the values of (αhv) 2 as a function of the fallen photon energy. The linear relationship between (αhv) 2 and hυ could be observed in high energy area of 8 -10 (eV/cm) 2 . By extrapolating the linear behavior of the curve, which represented the energy needed for the electron to move from valence band (VB) to conduction band (CB) [26].…”

“…The process of doping metal oxides semiconductors with the transition metals of the second group in the periodic table or their ions is considered as an important and interesting subject in many fields of applications [1], such as gas sensors [2], surface coatings, environmental and human health [3], organic pollutants and toxic water [4], photocatalysis [5], probe reaction to evaluate the catalytic activity [6], and nanocomposite or heterojunction catalysts [7]. Where a small amount of material from the transition group can have a significant and a clear effect on the properties of surface electrical conductivity [8].…”

A Novel Approach to Augment the Opto-Electronic Properties of Stannic Oxide (SnO2) Thin Films by Vanadium Doping

“…Its high chemical stability is considered to be an inherent advantage of SnO2 [10] and it makes SnO2 appreciably adoptable for applications in challenging atmosphere, for preparing transparent and strong-conductive electrode on photo enabled electrodes or as a selectively solar energy penetration coating [11,12]. Its applications include surface coatings, environmental and human health [13] gas sensors [14] organic pollutants and toxic water [15] and heterojunction catalysts [16], Tin dioxide (SnO2), having lattice parameters a = b = 4.737 Å and c = 3.826 Å with tetragonal Rutile structure is an important n-type semiconductor. Each tin atom at the corners of a regular octahedron is bounded to six oxygen atoms and three tin atoms surround each oxygen atom [17].…”