催化学报 ›› 2019, Vol. 40 ›› Issue (12): 1867-1873.DOI: 10.1016/S1872-2067(19)63331-0

• 论文 • 上一篇    下一篇

超小Ni-B纳米颗粒的合成与电催化性能研究

黄亭, 申涛, 龚明星, 邓邵峰, 赖成龙, 刘旭坡, 赵桐辉, 滕林, 王得丽   

  1. 华中科技大学化学与化工学院, 能量转换与存储材料化学教育部重点实验室, 材料化学与服役失效湖北省重点实验室, 湖北武汉 430074
  • 收稿日期:2019-01-27 修回日期:2019-03-04 出版日期:2019-12-18 发布日期:2019-09-21
  • 通讯作者: 王得丽
  • 基金资助:
    国家自然科学基金(21573083).

Ultrafine Ni-B nanoparticles for efficient hydrogen evolution reaction

Ting Huang, Tao Shen, Mingxing Gong, Shaofeng Deng, Chenglong Lai, Xupo Liu, Tonghui Zhao, Lin Teng, Deli Wang   

  1. Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
  • Received:2019-01-27 Revised:2019-03-04 Online:2019-12-18 Published:2019-09-21
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21573083), the 1000 Young Talent (to Deli Wang), and initiatory financial support from Huazhong University of Science and Technology (HUST). The authors thank the Analytical and Testing Center of HUST for allowing use of its facilities.

摘要: 寻找活性高、稳定性好、成本低廉的氢析出反应电催化剂是氢析出反应的最佳选择,故析氢催化剂的探究受到广泛关注.贵金属Pt基、Ir基和Ru基等催化剂具有优异的析氢催化活性以及稳定性,但贵金属的价格和储量问题导致其一直无法商业化应用.金属镍具有类Pt的电子结构,故将镍基材料应用于电催化析氢反应受到格外的重视.本文采用简单易行的化学还原-退火两步法合成了负载在Vulcan上的Ni-B纳米颗粒.XRD表征表明,煅烧前的Ni-B/C材料在45.36°处有一个钝峰,说明材料为无定形态,在25.21°处为碳材料(002)晶面的峰.退火后处理的样品Ni-B-200、Ni-B-300、Ni-B-400和Ni-B-500在45°、52°和76°左右有三个明显的峰,通过对比标准卡片(JCDPS87-0712)发现其分别归属于Ni的(111)、(200)和(220)晶面.随着温度的升高,特征峰向低角度略有偏移,表现出镍的晶格略有扩张,可能是B进入Ni晶格间隙造成的.从催化剂Ni-B、Ni-B-200、Ni-B-300、Ni-B-400和Ni-B-500的TEM图片中统计得到颗粒的平均粒径分别为9.0、11.0、16.4、17.9和20.6nm,说明随着温度的升高,Ni-B颗粒逐渐变大,且与根据XRD数据通过谢乐公式计算得到的各催化剂晶粒粒径大小的结果基本一致.XPS测试表明,相比于其他材料Ni的特征峰,Ni-B-400中Ni的键能向高的方向偏移,电子密度下降,有利于在析氢过程中吸附含氧物种,加快催化过程中的Volmer步骤,从而提高催化剂的析氢活性.样品Ni-B/C-400的Ni2+峰面积与Ni0峰面积的比值,为3.5,小于其他材料,表明该煅烧温度下能够得到具有更高比例单质Ni的材料,该结构有利于吸附氢原子,以便完成整个析氢过程.结合XPS、XRD及TEM表征可以推断,催化剂具有金属的核和NiO和B2O3的壳层,为核壳结构.在1mol/L KOH析氢测试中,催化剂Ni-B、Ni-B-200、Ni-B-300、Ni-B-400和Ni-B-500析氢电流密度达到10mA/cm2所需的过电位分别为104,119,123,114和146 mV;达到40 mA/cm2所需过电位为281、257、237、215和289mV.在这些催化剂中,Ni-B/C-400表现出最优的HER性能,达到40mA/cm2时过电位为215mV,最低的Tafel斜率80mV/dec,电化学耐久性高.Ni-B-400的高电催化HER性能可归因于以下几方面:一定的晶格膨胀;合适的Ni0/Ni2+配比;其结构较稳定,可以长期维持析氢稳定性.

关键词: Ni-B, 非贵金属电催化剂, 析氢反应, 超细纳米颗粒, 碱性电解质

Abstract: The search for active, stable, and cost-effective electrocatalysts for hydrogen evolution reaction (HER) is desirable, but it remains a great challenge in the overall water splitting. Here, we report the synthesis of nickel boron nanoparticles supported on Vulcan carbon (Ni-B) via a simple, yet scalable, two-step chemical reduction-annealing strategy. The results of the electrochemical measurements suggest that the overpotentials of Ni-B-400 are 114 and 215 mV (in 1 mol L-1 KOH) at current densities of 10 and 40 mA cm-2, respectively, indicating an exceedingly good electrocatalytic activity in the HER. More importantly, Ni-B maintains a current density of 7.6 mA cm-2 at an overpotential of 0.15 V for 20 h in the durability test. The excellent HER activity of Ni-B-400 is derived from the small particle size and the expanded lattice of Ni, which can optimize the hydrogen absorption energy and enhance the electrocatalytic properties.

Key words: Ni-B, Non-noble electrocatalyst, Hydrogen evolution reaction, Ultrafine nanoparticle, Alkaline electrolyte