The design of highly efficient, stable, and noble-metal-free bifunctional electrocatalysts for overall water splitting is critical but challenging. Herein, a facile and controllable synthesis strategy for nickel-cobalt bimetal phosphide nanotubes as highly efficient electrocatalysts for overall water splitting via low-temperature phosphorization from a bimetallic metal-organic framework (MOF-74) precursor is reported. By optimizing the molar ratio of Co/Ni atoms in MOF-74, a series of CoxNiyP catalysts are synthesized, and the obtained Co4Ni1P has a rare form of nanotubes that possess similar morphology to the MOF precursor and exhibit perfect dispersal of the active sites. The nanotubes show remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic performance in an alkaline electrolyte, affording a current density of 10 mA cm −2 at overpotentials of 129 mV for HER and 245 mV for OER, respectively. An electrolyzer with Co4Ni1P nanotubes as both the cathode and anode catalyst in alkaline solutions achieves a current density of 10 mA cm −2 at a voltage of 1.59 V, which is comparable to the integrated Pt/C and RuO 2 counterparts and ranks among the best of the metal-phosphide electrocatalysts reported to date.

A UiO type MOF with Lewis basic bipyridyl sites was synthesized and structurally characterized. After being activated by Soxhlet-extraction, this MOF exhibits high storage capacities for H 2 , CH 4 and CO 2 , and shows unusual stepwise adsorption for liquid CO 2 and solvents, indicating a sequential filling mechanism on different adsorption sites.Developing an effective system for carbon dioxide capture from anthropogenic emissions and finding appropriate mediums for energy gas (i.e., H 2 and CH 4 ) storage have been long term challenges, and will be increasingly urgent in future. 1 Physical sorption using solid state absorbents provides efficient alternatives owing to fast kinetics and high energy efficiency. 2 Indeed, some pilot plants for carbon dioxide capture and methane storage using solid state absorbents have been realized by some research groups. 3 Established as a new class of crystalline porous materials, metal-organic frameworks (MOFs) provide ideal platforms for such applications due to their intriguing structures, high surface area and tuneable functional pore environments. 4 In order to achieve high gas storage capacities or high selectivity, extensive efforts have been devoted to increase the affinity of frameworks with gas molecules, such as generating open metal sites 5 or tuning pore environments by immobilizing functional groups on the pore surface. 6 Immobilizing functional groups appears to be a promising strategy to tune the adsorption properties, especially for enhancing CO 2 binding strength by incorporating Lewis basic sites. However, the conventional strategy of anchoring the functional groups has some drawbacks. Along with the modification of the pore environments, the space occupation or blockage of functional groups always decreases the pore volume as well as specific surface areas significantly, which contrariwise lower the gas uptake capacities. 7 In this respect, the N-heterocyclic ligands are more attractive due to their benefits of constructing isomorphic MOFs and incorporating functional Lewis basic sites into the pore surface without declining their original pore spaces. 8 The UiO types of MOFs are an emerging class of MOFs that attract broad interest. 9 The highly porous structures and excellent stability of these types of MOFs allow them to be promising materials for the targets of CO 2 capture and energy gas storage. Up to now, extensive studies have been conducted based on UiO MOFs and their derivatives synthesized by functionalization/ modification on organic linkers. 10 Nevertheless, the gas sorption studies on UiO type MOFs incorporating Lewis basic pyridyl sites have never been investigated so far. The outstanding structural characteristics and excellent stability of UiO type MOFs motivate us to incorporate the pyridyl moieties into the frameworks, with the anticipation that it would further enhance the gas uptake capacities by anchoring the Lewis basic sites onto the pore surface but without sacrificing its original high porosity and exceptional robustness. He...

A type of metal–organic framework derived carbon combined with high density of pyridinic-N dopants and high degree of graphitization was prepared for effective oxygen reduction.