化学学报 ›› 2020, Vol. 78 ›› Issue (12): 1448-1454.DOI: 10.6023/A20070322 上一篇    下一篇

研究论文

B,N共掺杂的In2O3/TiO2制备与光催化产氢性能研究

李宸a,b, 陈凤华a, 叶丽a, 李伟a,b, 于晗a, 赵彤a,b   

  1. a 中国科学院化学研究所 极端环境高分子材料重点实验室 北京 100190;
    b 中国科学院大学 化学科学学院 北京 100190
  • 投稿日期:2020-07-20 发布日期:2020-11-04
  • 通讯作者: 陈凤华, 赵彤 E-mail:fhchen@iccas.ac.cn;tzhao@iccas.ac.cn
  • 基金资助:
    项目受国家自然科学基金(No.21604090)资助.

Preparation and Photocatalytic Hydrogen Production of B, N Co-doped In2O3/TiO2

Li Chena,b, Chen Fenghuaa, Ye Lia, Li Weia,b, Yu Hana, Zhao Tonga,b   

  1. a Key Laboratory of Science and Technology on High-tech Polymer Materials, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China;
    b School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
  • Received:2020-07-20 Published:2020-11-04
  • Supported by:
    Project supported by the National Natural Science Foundation of China (No. 21604090).

为拓宽TiO2的光吸收范围以及提高光生载流子的利用率,本工作利用B,N共掺杂改性的方法,通过聚合物前驱体法设计并制备了In2O3改性的TiO2光催化剂.在前驱体合成中引入了聚乙二醇(PEG)作为致孔剂.PEG在前驱体转化为无机氧化物的热处理过程中分解离去、形成介孔等不同尺度的孔隙,提高了样品的比表面积.异质结结构在产物中得到有效构筑,带隙宽度由P25的3.09 eV缩窄至2.71 eV(样品IT-500,500℃退火产物).B,N掺杂进入TiO2晶格内,形成了Ti-N-B和Ti-O-B结构,同时也存在N的填隙掺杂,有助于带隙的缩窄、并拓宽可见光吸收范围.In2O3/TiO2异质结结构的构筑,促进了电子-空穴对的分离与转移,提高了光生载流子的利用率.在大于380 nm可见光的照射下,样品IT-500的可见光催化产氢速率达到了5961 μmol·g-1·h-1,催化剂经过分离回收后进行循环实验,仍能保持良好的光催化活性.为了进一步提高其回收性,利用气纺丝制备了B,N掺杂的In2O3/TiO2纳米纤维棉,在最佳焙烧温度500℃下,所获得的纤维棉状光催化剂的氢气产生速率达到1186 μmol·g-1·h-1,纤维棉简化了回收再利用的过程,经过5次循环实验后仍能达到初始产氢速率的97%.

关键词: 光催化, TiO2, 非金属元素共掺杂, 异质结, 可见光响应, 纳米纤维

In order to improve light absorption range of TiO2 and utilization rate of photogenerated carriers, we use B, N co-doping and In2O3 blending to modify the TiO2 photocatalyst. Sample preparation is conducted through polymer precursor method and uniform distribution of the components is ensured. Polyethylene glycol (PEG) is added at the beginning of sample preparation and removed during the annealing process at high temperatures. X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission microscope (HRTEM), specific surface area and pore structure analyzer, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible absorption spectrum and photoluminescence (PL) spectroscopy are used to characterize the products obtained. B and N elements have been detected in the lattice of TiO2. Heterojunction structure of In2O3 and TiO2 are also observed. Formation of Ti-N-B and Ti-O-B structure is exhibited in this system. Interstitial doping of N is also observed. These factors contribute to narrow the band gap from 3.09 eV of P25 to 2.71 eV of IT-500 (the modified sample annealed at 500℃). With the introduction and pyrolysis of porogen PEG, mesoporous structure is successfully constructed. Visible light absorption range has been greatly broadened in this modified TiO2 based material. Utilization rate of photogenerated carriers has also been enhanced. When the catalyst is used in the photocatalytic hydrogen production experiment, under the irradiation of visible light (>380 nm), hydrogen production rate of IT-500 reaches 5961 μmol·g-1·h-1, which is far superior to commercial TiO2 and most of the TiO2 prepared by single modification method. The hydrogen production rate is maintained in the 5-circle test after the catalyst is separated and recycled. When the B, N-In2O3/TiO2 polymer precursor is gas sprayed, which uses polyvinylpyrrolidone as spinning aid, ethanol and acetic acid as solvents, nanofiber sponge can be obtained and used for hydrogen production. Hydrogen production rate of this material reaches 1186 μmol·g-1·h-1 and keeps 97% after 5-cycle test, which shows high potential for commercial use of this material.

Key words: photocatalysis, TiO2, Co-doping of non-metallic elements, heterojunction, visible-light response, nanofiber