1 徐州工程学院材料与化学工程学院，徐州 221018
2 北京航空航天大学杭州创新研究院，杭州 310051
石墨相氮化碳(g-C3N4)的研究已成为光催化领域热点。本文以三聚氰氨为前驱体，采用甲醇回流法制备Er掺杂的g-C3N4催化剂。利用扫描电镜(SEM)、X射线光电子能谱(XPS)、X射线衍射仪(XRD)、紫外-可见-近红外分光光度计(UV-Vis-NIR DRS)、傅里叶红外光谱仪(IR)、荧光光谱(PL)、物理吸附(N2-physisorption)及共聚焦显微镜(CLSM)等手段对Er/g-C3N4催化剂进行系统表征。结果表明，稀土金属Er高分散于g-C3N4上，促使氮化碳表面氮空穴的产生。Er掺杂优化了氮化碳的能带结构，增强了其对可见光的吸收，提升电子-空穴对的分离效率，此外还发现Er/g-C3N4具有较强的上转换能力。在660 nm红光LED照射下，对罗丹明B的水溶液进行光催化降解，发现Er/g-C3N4的降解速率是g-C3N4的2.0倍，且发现超氧自由基为该体系中的主要活性物种。
铒掺杂 甲醇回流法 光催化 红光 上转换 降解活性 g-C3N4 g-C3N4 Er doped methanol-refluxing method photocatalysis red light upconversion degradation activity
Author Affiliations
Abstract
1 School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, China
2 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3 Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
Stable 68 fs pulses with the average power of 1.5 W is directly generated from a multimode diode-pumped Kerr-lens mode-locked Yb:CYA laser by separating the gain medium and Kerr medium. The repetition rate is about 50 MHz, resulting in a single pulse energy of 30 nJ and a peak power of 0.44 MW. To the best of our knowledge, this is the highest single pulse energy ever produced from a mode-locked Yb:CYA oscillator. Our experimental results show that Yb:CYA crystal is an excellent candidate for multiwatt, sub-100 fs pulse generation in diode-pumped all-solid-state lasers. It is believed that the output power can be scalable to multi-W while the pulse duration is maintained with this simple method.
Mode-locked lasers Lasers, ytterbium Lasers, solid-state Photonics Research
2018, 6(2): 02000127
