pH-Universal Water Splitting Catalyst by Ru-Ni Nanosheet Assemblies
pH-Universal Water Splitting Catalyst by Ru-Ni Nanosheet Assemblies
复制标题
由 Ru-Ni 纳米片组件制成的 pH 通用水分解催化剂
DOI：
10.1016/j.isci.2019.01.004
复制
发表时间：
--
期刊：
影响因子：
5.8
通讯作者：
Huang Xiaoqing
中科院分区：
文献类型：
--
作者：
Yang Jian;Shao Qi;Huang Bolong;Sun Mingzi;Huang Xiaoqing
尽管电化学水分解是一种有效且绿色的生产氧气和氢气的方法，但实现在可变电解质中稳定的高效双功能催化剂仍然是一个重大挑战。在此，我们报道了一种由超薄Ru壳和Ru-Ni合金核组成的三维分级组装结构，作为在通用pH条件下发挥作用的催化剂。与典型的Ir/C-Pt/C体系相比，在通用pH值下表现出优异的催化性能和整体水分解的优异耐久性。 Ni的引入使Ru-Ni电催化剂的d带中心下移，从而调节表面电子环境。密度泛函理论结果表明，相互限制的 d 带相互作用降低了 (Ru, Ni) 和 (H, O) 的结合，更容易形成 O-O 和 H-H。结构引起的eg-dz2错位导致表面库仑斥力最小化，从而实现无障碍水分解过程。
Although electrochemical water splitting is an effective and green approach to produce oxygen and hydrogen, the realization of efficient bifunctional catalysts that are stable in variable electrolytes is still a significant challenge. Herein, we report a three-dimensional hierarchical assembly structure composed of an ultrathin Ru shell and a Ru-Ni alloy core as a catalyst functioning under universal pH conditions. Compared with the typical Ir/C-Pt/C system, superior catalytic performances and excellent durability of the overall water splitting under universal pH have been demonstrated. The introduction of Ni downshifts the d-band center of the Ru-Ni electrocatalysts, modulating the surface electronic environment. Density functional theory results reveal that the mutually restrictive d-band interaction lowers the binding of (Ru, Ni) and (H, O) for easier O-O and H-H formation. The structure-induced eg-dz2misalignment leads to minimization of surface Coulomb repulsion to achieve a barrier-free water-splitting process.