College of Materials and Chemical Engineering, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, No. 8, Daxue Road, Yichang, 443002, China.
School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210046, P. R. China.
Angew Chem Int Ed Engl. 2017 Oct 9;56(42):13001-13005. doi: 10.1002/anie.201707238. Epub 2017 Aug 18.
Reported herein are two new polymorphic Co-MOFs (CTGU-5 and -6) that can be selectively crystallized into the pure 2D or 3D net using an anionic or neutral surfactant, respectively. Each polymorph contains a H O molecule, but differs dramatically in its bonding to the framework, which in turn affects the crystal structure and electrocatalytic performance for hydrogen evolution reaction (HER). Both experimental and computational studies find that 2D CTGU-5 which has coordinates water and more open access to the cobalt site has higher electrocatalytic activity than CTGU-6 with the lattice water. The integration with co-catalysts, such as acetylene black (AB) leads to a composite material, AB&CTGU-5 (1:4) with very efficient HER catalytic properties among reported MOFs. It exhibits superior HER properties including a very positive onset potential of 18 mV, low Tafel slope of 45 mV dec , higher exchange current density of 8.6×10 A cm , and long-term stability.
本文报道了两种新的 Co-MOFs（CTGU-5 和 -6），它们可以分别使用阴离子或中性表面活性剂选择性地结晶成纯 2D 或 3D 网络。两种晶型都包含一个 H2O 分子，但与骨架的结合方式有很大的不同，这反过来又影响了晶体结构和析氢反应（HER）的电催化性能。实验和计算研究都发现，具有配位水和更多钴位点可及通道的 2D CTGU-5 比具有晶格水的 CTGU-6 具有更高的电催化活性。与助催化剂（如乙炔黑（AB））的结合导致复合材料 AB&CTGU-5（1:4）具有在报道的 MOFs 中非常高效的 HER 催化性能。它表现出优异的 HER 性能，包括非常正的起始电位 18 mV、低的 Tafel 斜率 45 mV·dec-1、更高的交换电流密度 8.6×10-3 A·cm-2 和长期稳定性。
