Enhanced anomalous photo-absorption from TiO2 nanostructures

Abstract

Two dimensional nanostructures have been created on the rutile TiO2 (110) surfaces via ion irradiation technique. Enhanced anomalous photo- absorption response is displayed, where nanostructures of 15 nm diameter with 0.5 nm height, and not the smaller nanostructures with larger surface area, delineate highest absorbance. Comprehensive investigations of oxygen vacancy states, on ion- irradiated surfaces, display a remarkable result that the number of vacancies saturates for higher fluences. A competition between the number of vacancy sites on the nanostructure in conjunction with its size is responsible for the observed anomalous photo-absorption.

Angle-Sensitive Photonic Crystals for Simultaneous Detection and Photocatalytic Degradation of Hazardous Diazo Compounds

“…An approximately six fold absorption enhancement for larger nanostructures of TiO 2 surface was reported in the literature [19]. Finally, past research has also attributed the absorption enhancement to the generation of titanium rich zones and crystalline TiO 2 nanostructures, specifically after the LPD of TiO 2 on the 2D-PhC surfaces, as reported in this study [18,19].…”

“…These peaks were designed to overlap with the absorption peak maxima (~495 nm and ~620 nm) of the target diazo compounds, CR and AB-10B, and were also predicted to be derived from resonant modes caused by stop bands of TiO2 coated 2D-PhC when the incident angle for light was 60° and 0°, respectively. Finally, due to the presence of 2D-PhC, it was shown ( Figure 3) that the confined light was localized on the TiO2 coated 2D-PhC surface, and the absorption intensity of peak maxima for the target dyes, CR and AB-10B, on the surface of the constructed device was enhanced by 73.37 ± 2.46% for CR and 67.82 ± 1.45% for AB-10B, compared to the reference [18]. Therefore, as shown in Figure 3, both 2D-PhC and the TiO2 coating were necessary for causing the absorption enhancement for the dyes.…”

Room temperature superparamagnetism in rutile TiO2 quantum dots produced via ECR sputtering

“…A significant decrease of reflectance, compared to pristine surface, is demonstrated for the nanostructured TiO 2 surfaces. Formation of TiO 2 nanostructures, with large surface area having enhanced absorption characteristics [14], may be responsible for this observations. Kubelka Munk function(KMF) defined as FðRÞ ¼ ð1 À RÞ 2 =2R for a given reflectance, R, provides important information about electronic transitions and bandgap energies [16].…”

“…[11]. Ion beam irradiation technique is an attractive technique for fabricating nanostructures since via this technique self assembled nanostructures are created in a single step process [12][13][14]. Here, the creation of nanostructures is effectively controlled through a competition between the curvature dependent radiation sputtering that roughens the surface and a variety of smoothening mechanisms.…”

“…Presence of small amount of V O on pristine TiO 2 , as shown by Solanki et. al [14],. can be responsible for the observation of mild ferromagnetic behavior here[4].…”