Jo Young Woong, Loka Chadrasekhar, Lee Kee-Sun, Lim Jae-Hyun
Department of Advanced Materials Engineering, Smart Natural Space Research Centre, Kongju National University Cheonan-31080 South Korea
Department of Computer Science and Engineering, Kongju National University Cheonan 331-717 South Korea.
RSC Adv. 2020 Apr 28;10(27):16187-16195. doi: 10.1039/d0ra01579b. eCollection 2020 Apr 21.
Semiconductor-based nanostructures which are photo-catalytically active upon solar light irradiation were extensively used for environmental remediation due to the potential decomposition of various kinds of pollutants. In this work, we report the preparation of a sustainable thin film composite, AgO/WO p-n heterojunction, and investigation of its photocatalytic activity. To achieve the composite structure, WO/Ag-WO layers were deposited over a quartz substrate by magnetron sputtering at room temperature and subsequently annealed at 823 to 923 K. The thin film structure, morphology, and chemical states were thoroughly characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron spectroscopy, and X-ray photoelectron spectroscopy. The obtained results revealed that the amorphous Ag-doped WO was crystallized into monoclinic WO and AgO, in which nanocrystalline AgO was diffused towards the surface of WO. Optical transmittance spectra recorded by UV-vis-NIR spectroscopy revealed that the WO/Ag-WO films became transparant in the visible region after annealing at high temperature (873 K and 923 K). The AgO/WO p-n heterojunction composite thin films showed high photocatalytic activity (0.915 × 10 min) under visible light irradiation, which is attributed to the efficiency of effective photogenerated charge-carrier formation and the reduced recombination rate of photogenerated electron-hole pairs. Unlike the powder-based photocatalysts, the reported thin film-based heterojunction photocatalyst could be very sustainable, and cost-effective.
基于半导体的纳米结构在太阳光照射下具有光催化活性，由于其对各种污染物的潜在分解能力，被广泛用于环境修复。在这项工作中，我们报告了一种可持续的薄膜复合材料AgO/WO p-n异质结的制备及其光催化活性的研究。为了实现复合结构，在室温下通过磁控溅射在石英衬底上沉积WO/Ag-WO层，随后在823至923K下退火。通过X射线衍射、场发射扫描电子显微镜、透射电子能谱和X射线光电子能谱对薄膜结构、形貌和化学状态进行了全面表征。所得结果表明，非晶态Ag掺杂的WO结晶为单斜WO和AgO，其中纳米晶AgO向WO表面扩散。通过紫外-可见-近红外光谱记录的光学透过率光谱表明，WO/Ag-WO薄膜在高温（873K和923K）退火后在可见光区域变得透明。AgO/WO p-n异质结复合薄膜在可见光照射下表现出高光催化活性（0.915×10分钟），这归因于有效光生电荷载流子形成的效率以及光生电子-空穴对复合率的降低。与粉末基光催化剂不同，所报道的基于薄膜的异质结光催化剂可能非常可持续且具有成本效益。
