Nano-photocatalytic decomposition of a stearic acid film deposited on the TiO2 by an atomic force microscope

Molecular-Level Insights into Photocatalysis from Scanning Probe Microscopy Studies on TiO2(110)

“…Furthermore, the estimated photodecomposition cross sections were relatively low (∼10 −21 cm 2 ), indicating that the rutile (011) surface does not possess higher photocatalytic activity in comparison with other rutile TiO 2 surfaces. In concluding this section, we point out SPM work on the photodecomposition of stearic acid on the TiO 2 (110) surface by Kobayashi et al 149,150 and by Sawunyama et al 151,152 Although these studies do not present atomically resolved images, they provide insights into the photodecomposition of stearic acid films on TiO 2 (110) (in air) using the stark contrast in height revealed by atomic force microscopy (AFM) between regions with and without adsorbed stearate. For example, Figure 24 illustrates the photodecomposition of stearic acid islands on TiO 2 (110) by Sawunyama et al 152 as detected by AFM.…”

Current-less photoreactivity catalyzed by functionalized AFM tips

“…Recently, Kobayashi et al have applied voltage through a conductive AFM tip to decompose stearic acid films as well as adsorbed oxygen molecules deposited on TiO 2 surfaces upon scanning at 10 V under ultraviolet irradiation. 6,7 In the present study, we have used a chemically-modified AFM probe to actively carry forth a highly localized photochemical reaction of a synthetic dye. In particular, by placing the TiO 2 powder catalyst onto the end of an AFM tip, we have been able to initiate a localized photochemical reaction of a synthetic textile dye within the spatially confined region where the tip traverses, leaving the rest of the sample surface unreacted.…”