Deng Shengjue, Zhong Yu, Zeng Yinxiang, Wang Yadong, Wang Xiuli, Lu Xihong, Xia Xinhui, Tu Jiangping
State Key Laboratory of Silicon MaterialsKey Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province Zhejiang University Hangzhou 310027 P. R. China.
School of Applied Physics and Materials Wuyi University Jiangmen Guangdong 529020 China.
Adv Sci (Weinh). 2017 Dec 19;5(3):1700772. doi: 10.1002/advs.201700772. eCollection 2018 Mar.
Designing ever more efficient and cost-effective bifunctional electrocatalysts for oxygen/hydrogen evolution reactions (OER/HER) is greatly vital and challenging. Here, a new type of binder-free hollow TiO@CoS core-branch arrays is developed as highly active OER and HER electrocatalysts for stable overall water splitting. Hollow core-branch arrays of TiO@CoS are readily realized by the rational combination of crosslinked CoS nanoflakes on TiO core via a facile and powerful sulfurization strategy. Arising from larger active surface area, richer/shorter transfer channels for ions/electrons, and reinforced structural stability, the as-obtained TiO@CoS core-branch arrays show noticeable exceptional electrocatalytic performance, with low overpotentials of 240 and 139 mV at 10 mA cm as well as low Tafel slopes of 55 and 65 mV Dec for OER and HER in alkaline medium, respectively. Impressively, the electrolysis cell based on the TiO@CoS arrays as both cathode and anode exhibits a remarkably low water splitting voltage of 1.56 V at 10 mA cm and long-term durability with no decay after 10 d. The versatile fabrication protocol and smart branch-core design provide a new way to construct other advanced metal sulfides for energy conversion and storage.
设计用于析氧反应/析氢反应（OER/HER）的效率更高且成本效益更高的双功能电催化剂至关重要且具有挑战性。在此，一种新型的无粘结剂空心TiO@CoS核-枝阵列被开发出来，作为用于稳定全水分解的高活性OER和HER电催化剂。通过一种简便且强大的硫化策略，在TiO核上合理组合交联的CoS纳米片，很容易实现TiO@CoS的空心核-枝阵列。由于具有更大的活性表面积、更丰富/更短的离子/电子传输通道以及增强的结构稳定性，所制备的TiO@CoS核-枝阵列表现出显著的优异电催化性能，在碱性介质中，对于OER和HER，在10 mA cm时的过电位分别为240和139 mV，Tafel斜率分别为55和65 mV Dec。令人印象深刻的是，基于TiO@CoS阵列作为阴极和阳极的电解池在10 mA cm时表现出极低的水分解电压1.56 V，并且具有长期耐久性，在10天后没有衰减。这种通用的制备方案和巧妙的枝-核设计为构建用于能量转换和存储的其他先进金属硫化物提供了一种新方法。
