化学学报 ›› 2017, Vol. 75 ›› Issue (10): 1003-1009.DOI: 10.6023/A17070298 上一篇    下一篇

研究论文

还原氧化石墨烯修饰泡沫镍原位负载MnO2对H2O2电还原反应催化性能的研究

宋聪颖, 孙逊, 叶克, 朱凯, 程魁, 闫俊, 曹殿学, 王贵领   

  1. 哈尔滨工程大学 材料科学与化学工程学院 哈尔滨 150001
  • 收稿日期:2017-07-04 出版日期:2017-10-15 发布日期:2017-09-06
  • 通讯作者: 王贵领,E-mail:wangguiling@hrbeu.edu.cn;Tel.:+86-451-82589036;Fax:+86-451-82589036 E-mail:wangguiling@hrbeu.edu.cn
  • 基金资助:

    国家自然科学基金(No.51572052)资助.

Electrocatalytic Activity of MnO2 Supported on Reduced Graphene Oxide Modified Ni Foam for H2O2 Reduction

Song Congying, Sun Xun, Ye Ke, Zhu Kai, Cheng Kui, Yan Jun, Cao Dianxue, Wang Guiling   

  1. College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001
  • Received:2017-07-04 Online:2017-10-15 Published:2017-09-06
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 51572052).

采用两步易操作的水热法制备了还原氧化石墨烯(rGO)修饰泡沫镍(Ni foam)基体原位负载MnO2纳米片(MnO2/rGO@Ni foam)催化剂电极.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对电极的微观形貌和组成进行了表征.利用循环伏安法和计时电流法对电极对H2O2电还原反应的催化性能进行了系统的测试.根据测试结果得知,电极在3 mol/L NaOH和1 mol/L H2O2溶液中表现出最佳的催化性能.在该溶液中,当电位为-0.8V时,H2O2电还原反应的电流密度可以达到240 mA/cm2,高于同等条件下MnO2直接生长在Ni foam上的电流密度180mA/cm2.通过不同温度下的极化曲线计算出了在该电极上H2O2电还原反应所需的活化能大小为21.53 kJ/mol,明显低于文献中报道的数值.对比实验结果表明rGO的加入显著地改善了MnO2催化剂的催化性能与稳定性.

关键词: MnO2, 还原氧化石墨烯, H2O2, 电催化, 水热法

Fuel cells which use hydrogen peroxide as oxidant have been widely studied and presents good development foreground. As a liquid fuel, H2O2 possesses advantages of easily storage and transportation which make it can be widely used in underwater and space as a power source. At present, the most widely used catalysts for H2O2 electroreduction are noble metal catalysts. Compared with noble metals, transition metal oxides possess advantages of low cost and extensive sources. However, the catalytic activity of transition metal oxides is still much lower than noble metals. Therefore, many efforts should be made to improve the electrochemical performance of transition metal oxides. In this work, rGO is used as an additive to improve the electrochemcial performance of MnO2. An original electrode of MnO2 in-situ supported on reduced graphene oxide modified Ni foam (MnO2/rGO@Ni foam) is prepared through two-step hydrothermal methods. Primarily, the novel current collector of rGO@Ni foam is obtained with larger surface area which is beneficial to the next loading of MnO2. Secondly, MnO2 is grown on the rGO@Ni foam also by a hydrothermal treatment. Besides large surface area, the addition of rGO can provide more channels for electron transfer and then accelerate the reaction rate of H2O2 reduction. The morphology and phase composition of the as-prepared electrode are investigated by measurements of X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). It can be concluded from SEM and TEM images, both rGO and MnO2 exhibit sheet-like structure and there are many gaps existing between these sheets. Especially, the as-prepared MnO2 nanosheets builds a honeycomb structure which makes positive effects on the contact between H2O2 and catalyst. And XRD and HRTEM results show that MnO2 and rGO are successfully prepared on Ni foam. The electrochemical performance of the MnO2/rGO@Ni foam electrode toward H2O2 reduction is investigated by cyclic voltammetry and chronoamperometry in a three-electrode system in solutions of NaOH and H2O2. Results reveal that the reduction current density of H2O2 reduction on the MnO2/rGO@Ni foam electrode reaches 240 mA/cm2 in a solution of 1.0 mol/L H2O2 and 3 mol/L NaOH at -0.8 V which is much higher than that on MnO2 directly supported on Ni foam (MnO2@Ni foam). At the same time, a better stability is also achieved on the MnO2/rGO@Ni foam electrode. Generally speaking, the addition of rGO highly improves the electrocatalytic activity and stability of the as-prepared electrode indicating great application prospect in the future.

Key words: MnO2, rGO, H2O2, electrocatalysis, hydrothermal method