N-doped carbon coated NiCo2S4 hollow nanotube as bifunctional electrocatalyst for overall water splitting
N-doped carbon coated NiCo2S4 hollow nanotube as bifunctional electrocatalyst for overall water splitting
复制标题
DOI：
10.1016/j.carbon.2019.01.065
复制
发表时间：
2019-04
期刊：
影响因子：
10.9
通讯作者：
Fang Li;Rongchen Xu;Yueming Li;F. Liang;Dafeng Zhang;Wen‐Fu Fu;Xiao-Jun Lv
中科院分区：
文献类型：
--
作者：
Fang Li;Rongchen Xu;Yueming Li;F. Liang;Dafeng Zhang;Wen‐Fu Fu;Xiao-Jun Lv
开发无贵金属的电催化剂，使水的电化学裂解成为电能-氢能转换的重要途径。Nisingle键Co基催化剂（NiCo_2S_4）含有Co_3 +/Co_2+和Ni_3 +/Ni_2+氧化还原对，是有效的HER和OER活性中心，但其过电位高、动力学滞后和稳定性差，抑制了其整体的水裂解活性和稳定性应用。本文以聚丙烯腈（PAN）为模板，采用简单的溶剂热法制备了N掺杂碳层包覆的NiCo 2S 4中空纳米管（NCT-NiCo 2S 4）。碳层包覆的中空纳米管结构不仅使催化活性中心最大化，促进传质速率，而且还保护电解质免受腐蚀，从而提高活性和稳定性。优化的催化剂表现出295和330 mV的低过电位，分别驱动HER和OER的100 mA cm− 2，同时保持显着的稳定性。小的Tafel斜率也反映了HER和OER的高电催化反应动力学。当组装在电解槽中作为水分解的催化剂时，在10 mA cm−2的电流密度下，它只需要1.6 V的电池电压。这一工作对能源化学功能材料的合理设计具有一定的指导意义。
Great attention has been focused on exploration of noble-metal free electrocatalysts to enable electrochemical water splitting for the process of the electricity-to-hydrogen energy conversion. The Nisingle bondCo based catalyst (NiCo2S4) contains the redox couples of Co3+/Co2+and Ni3+/Ni2+which are effective active centers for HER and OER, however, the high overpotential, delayed dynamics and inferior stability suppress their whole water splitting activity and stability application. Herein, N-doped carbon layer coated NiCo2S4hollow nanotubes (NCT-NiCo2S4) were prepared by simple solvothermal method using polyacrylonitrite (PAN) as template. The carbon layer coated hollow nanotube structure not only maximized the catalytic active sites, facilitated mass transfer rate but also protected from electrolyte corrosion to improve the activity and stability. The optimized catalyst presented low overpotentials of 295 and 330 mV to drive the 100 mA cm−2for HER and OER, respectively, meanwhile maintaining the remarkable stability. The small Tafel slope also reflects the high electrocatalytic reaction kinetic for HER and OER. When assembled in an electrolyzer as catalyst for water splitting, it only needs a cell voltage of 1.6 V at current density of 10 mA cm−2. This work sheds some light on the rational design of functional materials for energy chemistry.