| 학회 | 한국재료학회 |
| 학술대회 | 2017년 봄 (05/17 ~ 05/19, 목포 현대호텔) |
| 권호 | 23권 1호 |
| 발표분야 | 8. 태양광 물분해 광전극 및 광촉매(Photoelectrode and photocatalyst materials for solar water splitting) |
| 제목 | Characterizing photocatalytic activity in 2D heterostructures using spatially-resolved photoelectrochemical measurements |
| 초록 | Two-dimensional (2D) semiconductors such as MoS2 and WS2 have emerged as a promising non-precious and earth-abundant catalyst for photoelectrochemical (PEC) water splitting. Recently, considerable research efforts have focused on identifying the active sites such as atomic edges and vacancies in those layered materials and activating (or maximizing) such catalytic sties for efficient hydrogen evolution reaction (HER). In addition, the ability to create atomically thin 2D semiconductor heterostructures with designed energy alignment provide unprecedented possibilities in photocatalysis by controlling the chemical reactivity and charge transfer at the solid-liquid interface. Nevertheless, it is difficult to investigate the HER mechanism and to correlate PEC performance with the specific properties of the heterostructures because of ensemble averaging effects of various catalytic sites including step edges, vacancies, grain boundaries and chemical adsorbates present inhomogeneously on the surface. In this talk, we will present a new method for spatially-resolved and in-situ PEC characterization in 2D semiconductors and their heterostructures. For the measurement, a model system consisting of MoS2/WS2/WSe2/graphene heterostructures is fabricated within the miniaturized PEC cell using vdW assembly and micro-patterning techniques. By measuring the photocurrent upon scanning the focused laser spot, we could characterize the PEC performance of differently stacked structures. It enabled the visualization of enhanced HER in the MoS2/WS2 heterojunction compared with individual MoS2 or WS2 layers. Furthermore, the electrical field effect on HER of such a unique heterostructure will be discussed. |
| 저자 | 이철호 |
| 소속 | 고려대 |
| 키워드 | Solar water splitting; photocatalyst; 2D materials; transition metal dichalcogenides; 2D heterostructures |
