催化学报

催化学报 ›› 2018, Vol. 39 ›› Issue (6): 1090-1098.DOI: 10.1016/S1872-2067(18)63046-3

• 论文 • 上一篇    下一篇

介质阻挡放电等离子体法制备优异光催化合成过氧化氢性能的氮空穴掺杂石墨相氮化碳

李旭贺a, 张健a, 周峰b, 张洪亮a, 白金a, 王彦娟a, 王海彦a   

  1. a 辽宁石油化工大学石油化工辽宁省重点实验室, 辽宁抚顺 113001;
    b 中国石化抚顺石油化工研究院, 辽宁抚顺 113001
  • 收稿日期:2017-12-29 修回日期:2018-01-27 出版日期:2018-06-18 发布日期:2018-05-16
  • 通讯作者: 张健
  • 基金资助:

    辽宁省教育厅创新创业改革试点专业建设项目.

Preparation of N-vacancy-doped g-C3N4 with outstanding photocatalytic H2O2 production ability by dielectric barrier discharge plasma treatment

Xuhe Lia, Jian Zhanga, Feng Zhoub, Hongliang Zhanga, Jin Baia, Yanjuan Wanga, Haiyan Wanga   

  1. a Liaoning Key Laboratory of Petroleum & Chemical Industry, Liaoning Shihua University, Fushun 113001, Liaoning, China;
    b Fushun Research Institute of Petroleum and Petrochemicals, SINOPEC, Fushun 113001, Liaoning, China
  • Received:2017-12-29 Revised:2018-01-27 Online:2018-06-18 Published:2018-05-16
  • Contact: 10.1016/S1872-2067(18)63046-3
  • Supported by:

    This work was supported by the Pilot Program of University of Liaoning Innovation and Education Reform.

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摘要：

过氧化氢（H2O2）是一种绿色氧化剂，广泛应用于纺织、印染、造纸和医药等行业.目前，工业上采用蒽醌法制备H2O2，它由于需要多步加氢和氧化处理，因此能耗非常大.研究发现，采用贵金属催化剂可以将氢气和氧气直接合成H2O2，但催化剂价格过高，且反应本身存在爆炸风险.近年来，半导体光催化合成H2O2受到广泛关注.研究发现，在水存在下，光电子可以将氧气还原得到H2O2.介质阻挡放电（DBD）等离子体广泛应用于材料合成、挥发性有机物处理、汽车尾气净化和材料表面处理等.石墨相氮化碳（g-C3N4）是新型非金属光催化剂，以其性质稳定、能带适中和制备方便等优点而广受青睐.然而g-C3N4的比表面积和电荷分离效率较低，大大限制了其应用.
本文采用DBD等离子体法在氢气气氛下制备了N空穴掺杂的石墨相氮化碳，采用XRD，N2吸附，UV-Vis，SEM，TEM，XPS，EIS，EPR，O2-TPD及PL等方法对催化剂进行了表征，并考察了N空穴对催化剂结构性质、光学性质及光催化合成H2O2性能的影响.结果显示，当DBD等离子体处理时间小于30min时，所制催化剂颗粒尺寸显著小于焙烧法得到的，因而其比表面积显著提高.N空穴的引入降低了催化剂的能带，提高了可见光区的吸收.此外，N空穴作为反应活性位，既能吸附反应物氧气分子，又能捕获光电子并促进光电子从催化剂向氧气分子转移，进而发生后续还原反应.等离子体处理30min得到的催化剂光催化合成H2O2性能最佳，是纯g-C3N4的11倍.本文为g-C3N4基催化剂的制备提供了一个新方法.

关键词: 介质阻挡放电等离子体, 石墨相氮化碳, 过氧化氢合成, 氮空穴, 光催化

Abstract:

Dielectric barrier discharge (DBD) plasma is considered to be a promising method to synthesize solid catalysts. In this work, DBD plasma was used to synthesize a nitrogen-vacancy-doped g-C3N4 catalyst in situ for the first time. X-ray diffraction, N2 adsorption, ultraviolet-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, electron paramagnetic resonance, O2 temperature-programmed desorption, and photoluminescence were used to characterize the obtained catalysts. The photocatalytic H2O2 production ability of the as-prepared catalyst was investigated. The results show that plasma treatment influences the morphology, structure, and optical properties of the as-prepared catalyst. Nitrogen vacancies are active centers, which can adsorb reactant oxygen molecules, trap photoelectrons, and promote the transfer of photoelectrons from the catalyst to the adsorbed oxygen molecules for the subsequent reduction reaction. This work provides a new strategy for synthesizing g-C3N4-based catalysts.

Key words: Dielectric barrier discharge plasma, Graphitic carbon nitride, H2O2 production, Nitrogen vacancies, Photocatalysis