Ultrathin Films of TiO₂ Nanoparticles at Interfaces

Abstract

The properties of a material change remarkably as a result of the scaling dimensions. The Langmuir–Blodgett (LB) film deposition technique is known to offer precise control over the film thickness and the interparticle separation. To form a well-ordered LB film, it is essential to form a stable Langmuir film at the air–water interface. Here, we report our studies on ultrathin films of TiO2 nanoparticles at air–water and air–solid interfaces. The Langmuir film of TiO2 nanoparticles at the air–water interface was found to be very stable, and it exhibits loose-packing and close-packing phases. The LB films were transferred onto solid substrates for characterization and application. The surface morphology of the LB film was obtained by a field emission scanning electron microscope. The optical and electronic properties of the LB films of TiO2 nanoparticles were studied using UV–vis spectroscopy and current–voltage measurements, respectively. The LB film of TiO2 nanoparticles was employed for ethanol gas sensing, and the sensing performance was compared to that of bulk material. Because of the enormous gain in the surface to volume ratio and the increase in crystalline defect density in the ultrathin LB film of TiO2 nanoparticles, the LB film is found to be a potential functional layer for ethanol sensing as compared to the bulk material.

SnO2/TiO2 Thin Film n-n Heterostructures of Improved Sensitivity to NO2

“…Glancing incidence GID X-ray diffraction XRD patterns of the most representative samples prepared in this work are shown in Figure 5 ratio (Figure 7a), advantageous from the point of view of gas sensing. A similar morphology has been reported by Choudhary et al [61] for ultrathin TiO2 layers grown by the same technique. As far as the morphology of SnO2 thin films deposited by sputtering is concerned, it is typical to observe a columnar mode of growth [37].…”

“…Then, the previously obtained layer is immersed in the proper solution (e.g., potassium titanium oxalate, PTO [76,77] or SnO 2 derivatives) and thermally treated. There are few reports on using the L-B method to form thin films directly from crystallites of metal oxides [61,78,79].…”

Nanoscale TiO2 films and their application in remediation of organic pollutants

“…TiO 2 is chemically inert, corrosion resistant, relatively non-toxic, inexpensive, and does not contribute any chemical or hazardous waste to the environment [3][4][5]. Consequently, it has been widely used in academic research and a variety of commercial applications, ranging from anti-fogging paints [6], photovoltaics (such as solar cells) [7,8], sensing applications [9,10] and photocatalysis of organic pollutants [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26].…”

A model of compression isotherms for analyzing particle layers

“…(9). Eh represents energy required to build a condensed monolayer in a MLPD state and may be discussed in terms of molecular interaction involved in film formation.…”

“…It was shown in the literature that partially wettable particles form cohesive films at liquid-liquid and liquid-gas interfaces [1][2][3][4][5][6][7][8][9]. The particle films have numerous applications in tion and formation of a cohesive layer on the water surface [19]; in the case of hydrophilic spheres, this contact is weakened by hydration shells.…”