离子束辅助沉积法制备重掺N氧化铈提高其可见光吸收性能

Enhanced visible light adsorption of heavily nitrogen doped CeO2 thin film via ion beam assisted deposition

摘要:

氧化铈是一种潜在的可见光催化材料，但是如何实现在氧化铈晶格内的N掺杂是阻碍其发展的主要原因。本研究中，我们采用离子束辅助沉积法制备了N掺杂的氧化铈薄膜材料，采用该方法实现了对氧化铈薄膜的高含量N掺杂，N含量可高达25%，远远高于采用传统方法制备的氮掺杂氧化铈。N 1s的高分辨谱显示，掺杂的N替代了氧化铈中的O而实现了N在氧化铈晶格中的掺杂。XRD结果显示，氧化铈薄膜在生长过程中，N离子的轰击并没有改变氧化铈的晶体结果，但是改变了氧化铈薄膜表面形貌，从SEM结果上可以看出氧化铈表面颗粒变得细小，薄膜表面变得光滑。紫外可见吸收光谱结果显示，随着掺N量的增加，氧化铈的光吸收发生红移。

Abstract:

CeO2 is a promising material for the utilization of solar light in photocatalytic reactions. However, the major obstacle for the studies is the lack of reliable methods to incorporate the desired elements such as nitrogen into the crystal lattice of CeO2. In this study, nitrogen-doped CeO2 thin film was synthesized by IBAD technique. With this technique, the nitrogen can be heavily and uniformly doped in CeO2 thin films. XPS analysis results clearly demonstrated the greatest N contraction of 25 mol% can be achieved in CeO2 thin films which was much higher than that via traditional methods. The high resolution N 1s spectrum shows that nitrogen dopants were uniformly doped into CeO2 lattice by substituting O via IBAD. The XRD results indicated ion bombardment on the growing film surface did not alter the crystal structure of the film by itself. Instead, the heavy nitrogen doping can induce smaller grain size of CeO2. The SEM images showed that with the increase of N doping, the surface became smoother with smaller particle size. The heavily nitrogen doping can also induce a red shift of the visible light absorbance from 380 to 450 nm.