中国物理B ›› 2019, Vol. 28 ›› Issue (4): 48101-048101.doi: 10.1088/1674-1056/28/4/048101

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Photoelectrocatalytic oxidation of methane into methanol and formic acid over ZnO/graphene/polyaniline catalyst

Jia Liu(刘佳), Ying-Hua Zhang(张英华), Zhi-Ming Bai(白智明), Zhi-An Huang(黄志安), Yu-Kun Gao(高玉坤)   

  1. School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • 收稿日期:2018-10-16 修回日期:2019-01-10 出版日期:2019-04-05 发布日期:2019-04-05
  • 通讯作者: Zhi-Ming Bai E-mail:baizhiming2008@126.com
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 51602021 and 51474017) and the Fundamental Research Funds for the Central Universities (Grant No. FRF-TP-15-107A1).

Photoelectrocatalytic oxidation of methane into methanol and formic acid over ZnO/graphene/polyaniline catalyst

Jia Liu(刘佳), Ying-Hua Zhang(张英华), Zhi-Ming Bai(白智明), Zhi-An Huang(黄志安), Yu-Kun Gao(高玉坤)   

  1. School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2018-10-16 Revised:2019-01-10 Online:2019-04-05 Published:2019-04-05
  • Contact: Zhi-Ming Bai E-mail:baizhiming2008@126.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 51602021 and 51474017) and the Fundamental Research Funds for the Central Universities (Grant No. FRF-TP-15-107A1).

摘要:

ZnO/graphene/polyaniline (PANI) composite is synthesized and used for photoelectrocatalytic oxidation of methane under simulated sun light illumination with ambient conditions. The photoelectrochemical (PEC) performance of pure ZnO, ZnO/graphene, ZnO/PANI, and ZnO/graphene/PANI photoanodes is investigated by cyclic voltammetry (CV), chronoamerometry (J-t) and electrochemical impedance spectroscopy (EIS). The yields of methane oxidation products, mainly methanol (CH3OH) and formic acid (HCOOH), catalysed by the synthesized ZnO/graphene/PANI composite are 2.76 and 3.20 times those of pure ZnO, respectively. The mechanism of the photoelectrocatalytic process converting methane into methanol and formic acid is proposed on the basis of the experimental results. The enhanced photoelectrocatalytic activity of the ZnO/graphene/PANI composite can be attributed to the fact that graphene can efficiently transfer photo-generated electrons from the inner region to the surface reaction to form free radicals due to its superior electrical conductivity as an inter-media layer. Meanwhile, the introduction of PANI promotes solar energy harvesting by extending the visible light absorption and enhances charge separation efficiency due to its conducting polymer characteristics. In addition, the PANI can create a favorable π-conjunction structure together with graphene layers, which can achieve a more effective charge separation. This research demonstrates that the fabricated ZnO/graphene/PANI composite promises to implement the visible-light photoelectrocatalytic methane oxidation.

关键词: methane conversion, photoelectrocatalysis, methanol, formic acid, ZnO NWAs, polyaniline

Abstract:

ZnO/graphene/polyaniline (PANI) composite is synthesized and used for photoelectrocatalytic oxidation of methane under simulated sun light illumination with ambient conditions. The photoelectrochemical (PEC) performance of pure ZnO, ZnO/graphene, ZnO/PANI, and ZnO/graphene/PANI photoanodes is investigated by cyclic voltammetry (CV), chronoamerometry (J-t) and electrochemical impedance spectroscopy (EIS). The yields of methane oxidation products, mainly methanol (CH3OH) and formic acid (HCOOH), catalysed by the synthesized ZnO/graphene/PANI composite are 2.76 and 3.20 times those of pure ZnO, respectively. The mechanism of the photoelectrocatalytic process converting methane into methanol and formic acid is proposed on the basis of the experimental results. The enhanced photoelectrocatalytic activity of the ZnO/graphene/PANI composite can be attributed to the fact that graphene can efficiently transfer photo-generated electrons from the inner region to the surface reaction to form free radicals due to its superior electrical conductivity as an inter-media layer. Meanwhile, the introduction of PANI promotes solar energy harvesting by extending the visible light absorption and enhances charge separation efficiency due to its conducting polymer characteristics. In addition, the PANI can create a favorable π-conjunction structure together with graphene layers, which can achieve a more effective charge separation. This research demonstrates that the fabricated ZnO/graphene/PANI composite promises to implement the visible-light photoelectrocatalytic methane oxidation.

Key words: methane conversion, photoelectrocatalysis, methanol, formic acid, ZnO NWAs, polyaniline

中图分类号:  (II-VI semiconductors)

  • 81.05.Dz
81.05.Fb (Organic semiconductors) 81.05.ue (Graphene) 81.07.-b (Nanoscale materials and structures: fabrication and characterization)