无机材料学报 ›› 2022, Vol. 37 ›› Issue (7): 731-740.DOI: 10.15541/jim20210535 CSTR: 32189.14.10.15541/jim20210535

所属专题: 【能源环境】光催化(202312) 【信息功能】MAX层状材料、MXene及其他二维材料(202409)

• 研究论文 • 上一篇    下一篇

水凝胶负载的纳米银/氮化碳光催化剂的制备及性能研究

王晓俊1(), 许文2, 刘润路1, 潘辉1,3(), 朱申敏1()   

  1. 1.上海交通大学 金属基复合材料国家重点实验室, 上海 200240
    2.上海绘兰材料科技有限公司, 上海 201507
    3.上海交通大学 化学化工学院, 上海 200240
  • 收稿日期:2021-08-27 修回日期:2022-01-24 出版日期:2022-07-20 网络出版日期:2022-02-21
  • 通讯作者: 朱申敏, 教授. E-mail: smzhu@sjtu.edu.cn;
    潘 辉, 博士. E-mail: panhui115@hotmail.com
  • 作者简介:王晓俊(1999-), 男, 学士. E-mail: chunyu@sjtu.edu.cn
  • 基金资助:
    国家自然科学基金(51672173)

Preparation and Properties of Ag@C3N4 Photocatalyst Supported by Hydrogel

WANG Xiaojun1(), XU Wen2, LIU Runlu1, PAN Hui1,3(), ZHU Shenmin1()   

  1. 1. State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China
    2. Shanghai Huilan Material Technology Co., LTD, Shanghai 201507, China
    3. School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
  • Received:2021-08-27 Revised:2022-01-24 Published:2022-07-20 Online:2022-02-21
  • Contact: ZHU Shenmin, professor. E-mail: smzhu@sjtu.edu.cn;
    PAN Hui, PhD. E-mail: panhui115@hotmail.com
  • About author:WANG Xiaojun (1999-), male, Bachelor. E-mail: chunyu@sjtu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(51672173)

摘要:

石墨相氮化碳(g-C3N4)具有独特的二维平面结构和半导体能带结构, 广泛应用于光催化。但其又存在光生电子空穴对复合过快、可见光利用效率低、在水中分散性差等问题, 阻碍了其实际应用。本研究以海藻酸钠制备的水凝胶为基体, 通过与负载银纳米颗粒(AgNPs)的g-C3N4复合, 提升光生电子-空穴的分离效率, 同时解决催化剂在水中的分散性问题, 改善其光催化性能。首先, 采用热聚合法合成g-C3N4, 结合超声的高能量使其剥离成纳米片; 然后采用溶液法在g-C3N4表面原位生成银纳米颗粒, 制备得到负载银纳米颗粒的g-C3N4(Ag@C3N4); 最后以海藻酸钠(SA)为前驱体通过钙离子交联的方法得到负载有Ag@C3N4的水凝胶(SA/Ag@C3N4)。通过不同手段表征SA/Ag@C3N4的形貌、微观结构和相组成; 以甲基橙为模型物, SA/Ag@C3N4的光催化降解速率是Ag@C3N4的2.5倍。通过光致发光谱、时间分辨光致发光谱、电子顺磁共振波谱等表征手段对材料的催化机理进行探究。结果显示, 体系中银纳米颗粒表面等离子体共振效应与海藻酸钠水凝胶的多孔结构及传质通道发挥协同效应, 促进了光催化性能的提升。

关键词: 氮化碳, 银纳米颗粒, 海藻酸钠, 水凝胶, 光催化

Abstract:

Graphitic carbon nitride (g-C3N4) is widely used in the field of photocatalysis due to its unique two-dimensional planar structure and suitable energy band structure. However, it has some disadvantages such as fast recombination of the electron-hole, low visible-light utilization efficiency and poor dispersion in water, which hinder its application. In this study, the hydrogel prepared by sodium alginate was used as matrix to improve the dispersion of Ag@C3N4 composite in water, and at the same time enhanced the separation efficiency of photoelectron-holes pairs, thus improving its photocatalytic performance. Firstly, g-C3N4 was synthesized by thermal polymerization and then exfoliated into nanosheets by ultrasound. Then, Ag nanoparticles were deposited in situ on the surface of g-C3N4 by solution method to prepare Ag@C3N4. Finally, hydrogel loaded with Ag@C3N4 (SA/Ag@C3N4) was obtained by using calcium ion as crosslinker and sodium alginate (SA) as precursor. The morphology, microstructure and phase composition of the as-prepared photocatalyst were characterized. The as-prepared SA/Ag@C3N4 exhibited a 1.5 times higher photocatalytic degradation rate of methyl orange than that of Ag@C3N4. The catalytic mechanism was investigated by photoluminescence spectrum, time resolved photoluminescence spectrum and electron paramagnetic resonance spectrum. The results showed that the surface plasmon resonance effect of silver nanoparticles together with the porous structure and mass transfer channel of sodium alginate hydrogel plays a synergistic role in the enhancement of photocatalytic performance.

Key words: carbon nitride, silver nanoparticles, sodium alginate, hydrogel, photocatalysis

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