For electrochemical energy conversion, highly efficient and inexpensive electrocatalysts are required, which are principally designed and synthesized by virtue of structural regulations. Herein, we propose a rational linker scission approach to induce lattice strain in metal–organic framework (MOF) catalysts by partially replacing multicoordinating linkers with nonbridging ligands. Strained NiFe-MOFs with 6% lattice expansion exhibit a superior catalytic performance for the oxygen evolution reaction (OER) under alkaline conditions; the overpotential is reduced to 230 mV (86.6 mV dec–1) from 320 mV (164.9 mV dec–1) for the unstrained NiFe-MOFs at a current density of 10 mA cm–2. Operando studies by using synchrotron radiation X-ray absorption and infrared spectroscopy identified the emergence of a key *OOH intermediate on Ni3+/4+ sites during OER, providing strong evidence that the Ni3+/4+ sites are the active sites and the formation of *OOH is the rate-limiting step. The first-principles calculations were performed to reveal the strain-induced electronic structure changes of the NiFe-MOFs and the Gibbs free energy profile during OER. It is found that the optimized Ni 3d eg-orbital facilitates the formation of *OOH, thus enhancing the OER performance of the strained MOFs.

Graphene is extremely promising for next-generation spintronics applications; however, realizing graphene-based room-temperature magnets remains a great challenge. Here, we demonstrate that robust room-temperature ferromagnetism with TC up to ∼400 K and saturation magnetization of 0.11 emu g−1 (300 K) can be achieved in graphene by embedding isolated Co atoms with the aid of coordinated N atoms. Extensive structural characterizations show that square-planar Co-N4 moieties were formed in the graphene lattices, where atomically dispersed Co atoms provide local magnetic moments. Detailed electronic structure calculations reveal that the hybridization between the d electrons of Co atoms and delocalized pz electrons of N/C atoms enhances the conduction-electron mediated long-range magnetic coupling. This work provides an effective means to induce room-temperature ferromagnetism in graphene and may open possibilities for developing graphene-based spintronics devices.

Single-atom-layer catalysts with fully activated basal-atoms will provide asolution to the low loading-density bottlenecko fs ingle-atom catalysts.H erein, we activate the majority of the basal sites of monolayer MoS 2 ,b yd oping Co ions to induce long-range ferromagnetic order.This strategy,as revealed by in situ synchrotron radiation microscopic infrared spectroscopya nd electrochemical measurements,c ould activate more than 50 %ofthe originally inert basal-plane Satoms in the ferromagnetic monolayer for the hydrogen evolution reaction (HER). Consequently,o nas ingle monolayer of ferromagnetic MoS 2 measured by on-chip micro-cell, acurrent density of 10 mA cm À2 could be achieved at the overpotential of 137 mV,c orresponding to am ass activity of 28, 571 Ag À1 , which is two orders of magnitude higher than the multilayer counterpart. Its exchange current density of 75 mAcm À2 also surpasses most other MoS 2-based catalysts.E xperimental results and theoretical calculations showthe activation of basal plane Sa toms arises from an increase of electronic density around the Fermi level, promoting the Hadsorption ability of basal-plane Satoms.