16:00 〜 18:00
▲ [16p-PA10-9] The charge state of steps on TiO2 anatase (101) by AFM/KPFM
キーワード：AFM, KPFM, anatase
Step on anatase (101) surface as an important surface defect strongly influences the surface chemistry. A detailed picture of step properties may help to understand reactivity and overall materials performance in many applications [1].The step structures on anatase (101) are complex, and it is found that step B has stronger charge trapping characteristics [2]. However, the charge state of other steps and their different origin are still unclear. In this work, the structure and charge of different steps on the anatase (101) surface are investigated by AFM/KPFM at 78 K. Step shows high charge trapping properties results in a higher reactivity of the steps towards adsorbates, and further enhanced catalytic.
The steps on the anatase (101) surface were observed with simultaneously topography, CPD and current images by AFM/KPFM as shown in Fig.1. The four steps can be clearly obtained in the topography (a). Step A and B are parallel along [010] marked by the green and black lines. Step C along direction and step D along direction are distributed on both sides of steps A and B marked by blue and red lines. In Fig.1 (d), we known that the heights of the different steps are almost the same. And charge states of steps are different in Fig.1 (e) and Fig.1 (f). Step B has stronger charge trapping properties (0.27V and 150pA) than steps A, C, and D. It is difficult to clearly distinguish the difference between steps C and D in Fig.1 (e) and Fig.1 (f). From line profiles of the CPD image in Fig.1(b), we found that step A has the different CPD value compared with steps C and D in Fig.1 (e). This difference has not found in the line profiles of current image in Fig.1 (c) as shown in Fig.1 (f). This study demonstrates how steps charge properties can be used by adsorbates, enhancing catalytic and allowing one to design high-performance transition-metal oxide catalysts.
The steps on the anatase (101) surface were observed with simultaneously topography, CPD and current images by AFM/KPFM as shown in Fig.1. The four steps can be clearly obtained in the topography (a). Step A and B are parallel along [010] marked by the green and black lines. Step C along direction and step D along direction are distributed on both sides of steps A and B marked by blue and red lines. In Fig.1 (d), we known that the heights of the different steps are almost the same. And charge states of steps are different in Fig.1 (e) and Fig.1 (f). Step B has stronger charge trapping properties (0.27V and 150pA) than steps A, C, and D. It is difficult to clearly distinguish the difference between steps C and D in Fig.1 (e) and Fig.1 (f). From line profiles of the CPD image in Fig.1(b), we found that step A has the different CPD value compared with steps C and D in Fig.1 (e). This difference has not found in the line profiles of current image in Fig.1 (c) as shown in Fig.1 (f). This study demonstrates how steps charge properties can be used by adsorbates, enhancing catalytic and allowing one to design high-performance transition-metal oxide catalysts.