Chinese Journal of Catalysis ›› 2021, Vol. 42 ›› Issue (5): 781-794.DOI: 10.1016/S1872-2067(20)63690-7

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MgO and Au nanoparticle Co-modified g-C3N4 photocatalysts for enhanced photoreduction of CO2 with H2O

Naixu Lia,c, Meiyou Huanga, Jiancheng Zhoua,c,*(), Maochang Liub,d,#(), Dengwei Jingb,$()   

  1. aSchool of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, Jiangsu, China
    bInternational Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China
    cJiangsu Key Laboratory for Biomass Energy and Material, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing 210042, Jiangsu, China
    dSuzhou Academy of Xi’an Jiaotong University, Suzhou 215123, Jiangsu, China
  • Received:2020-05-09 Accepted:2020-05-09 Online:2021-05-18 Published:2021-01-29
  • Contact: Jiancheng Zhou,Maochang Liu,Dengwei Jing
  • About author:$ Tel: +86-29-82668721; E-mail: dwjing@mail.xjtu.edu.cn
    # Tel: +86-29-82668296-18; E-mail: maochangliu@mail.xjtu.edu.cn;
    * Tel: +86-25-52090618; E-mail: jczhou@seu.edu.cn;
  • Supported by:
    National Key Research and Development Program of China(2018YFB1502000);Newton Advanced Fellowship of the Royal Society(NA191163);National Natural Science Foundation of China(21576050);National Natural Science Foundation of China(51602052);National Natural Science Foundation of China(51672210);Jiangsu Provincial Natural Science Foundation of China(BK20150604);Fundamental Research Funds for the Central Universities of China(3207045403);Fundamental Research Funds for the Central Universities of China(3207045409);Fundamental Research Funds for the Central Universities of China(3207046414);Foundation of Jiangsu Key Laboratory for Biomass Energy and Material(JSBEM202001);Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions;Zhongying Young Scholar of Southeast University

Abstract:

The photoreduction of CO2 to achieve high-value-added hydrocarbons under simulated sunlight irradiation is advantageous, but challenging. In this study, a series of MgO and Au nanoparticle-co-modified g-C3N4 photocatalysts were synthesized and subsequently applied for the photocatalytic reduction of CO2 with H2O under simulated solar irradiation. The best photocatalytic performance was demonstrated by the Au and 3% MgO-co-modified g-C3N4 photocatalysts with CO, CH4, CH3OH, and CH3CHO yields of 423.9, 83.2, 47.2, and 130.4 μmol/g, respectively, in a 3-h reaction. We investigated the effects of MgO and Au as cocatalysts on photocatalytic behaviors, respectively. The characterizations and experimental results showed that the enhanced photocatalytic activity was due to the synergistic effect among the components of the ternary photocatalyst. The cocatalyst MgO can activate CO2 (adsorbed at the interface between the MgO and Au particles), and the Mg-N bonds formed in the MgO-CN nanosheets played an important role in the charge transfer. Meanwhile, the Au particles that were modified into MgO/g-C3N4 can increase the absorption of visible light via the surface plasmon resonance effect and further reduce the activation energies of the photoreduction of CO2 using H2O. This study provided an effective method for the modification of traditional primary photocatalysts with promising performance for photocatalytic CO2 reduction.

Key words: CO2 photoreduction, MgO, Au, g-C3N4, Photocatalysis, Synergistic effect, Cocatalyst