No abstract

Electrocatalytic reduction of water via hydrogen evolution reaction (HER) is considered one of the most ideal avenues to produce high-purity hydrogen (H 2 ) in large quantities, which always requires active electrocatalysts to overcome the high energy barrier. It is of significance yet challenging to design and construct effective HER electrocatalysts of an acceptable cost. In this study, a highly efficient metal−organic framework (MOF)-based electrochemical HER system based on NiRu-based binary MOF (Ru-doped Ni 2 (BDC) 2 TED MOF, BDC = 1,4-benzenedicarboxylic acid; TED = triethylenediamine) nanosheets grown on conductive substrates (e.g., Ni foam, carbon cloth) is fabricated by a facile solvothermal method. The resultant NiRu-MOF-based composites possess enhanced electron transport ability and water stability, accompanied by increased electrochemically active areas and hydrophilic/aerophobic properties. With these advantages, the optimized NiRu-MOF nanosheet arrays on Ni foam substrate (NiRu-MOF/NF) with a Ru/Ni molar ratio of 6/94 in the MOF structure could exhibit efficient catalytic performance for HER in alkaline conditions, requiring a small overpotential of 51 mV at −10 mA cm −2 . This study could provide a feasible way for the design and synthesis of two-dimensional (2D) MOF-based materials with controllable interface properties for energy catalysis and beyond.

Electrocatalytic nitrogen fixation provides a green and facile strategy for efficient synthesis of ammonia under ambient conditions, but it lacks efficient and inexpensive electrocatalysts for the nitrogen reduction reaction. Here, we report the synthesis of porous Fe2O3 nanorods grown on carbon cloth (p-Fe2O3/CC) via a surfactant-free hydrothermal reaction coupled with high-temperature calcination. The obtained p-Fe2O3/CC serves as a superior electrocatalyst for producing ammonia by electrolysis of nitrogen and water in neutral electrolytes (0.1 M Na2SO4). Benefiting from its binder-free characteristic and porous structure, p-Fe2O3/CC achieves superior catalytic performance and excellent long-term stability. This study is significant to design low-cost and binder-free porous Fe-based arrays as effective and stable electrocatalysts for electrochemical ammonia synthesis.

Boron-doped silver nanosponges synthesized from a one-step method exhibit superior performance for the electrocatalytic nitrogen reduction reaction.

Electrochemical water splitting is one hopeful strategy for hydrogen production, and designing efficient hydrogen evolution electrocatalysts under universal pH is one of the most critical topics. Here, we have successfully prepared mesoporous bimetallic core–shell nanostructures with Au nanowires (Au NWs) as cores and mesoporous Rh as shells (Au@mRh NWs). Due to the one-dimensional structure and mesoporous core–shell structure, Au@mRh NWs possess more active sites and provide the synergistic effect, leading to the great improvement of the electrochemical activity toward the hydrogen evolution reaction under a wide range of pH. The present work proposes a versatile strategy for preparing a bimetallic core–shell structure with a mesoporous shell, which is highly promising for more electrocatalytic applications.