title: MOF-Derived Noble Metal Free Catalysts for Electrochemical Water Splitting.
abstract: Noble metal free electrocatalysts for water splitting are key to low-cost, sustainable hydrogen production. In this work, we demonstrate that metal-organic frameworks (MOFs) can be controllably converted into catalysts for the oxygen evolution reaction (OER) or the hydrogen evolution reaction (HER). The OER catalyst is composed of FeNi alloy nanoparticles encapsulated in N-doped carbon nanotubes, which is obtained by thermal decomposition of a trimetallic (Zn2+, Fe2+, and Ni2+) zeolitic imidazolate framework (ZIF). It reaches 10 mA cm-2at the overpotential of 300 mV with a low Tafel slope of 47.7 mV dec-1. The HER catalyst consists of Ni nanoparticles coated with a thin layer of N-doped carbon. It is obtained by thermal decomposition of a Ni-MOF in NH3. It shows low overpotential of only 77 mV at 20 mA cm-2with low Tafel slope of 68 mV dec-1. The above noble metal free OER and HER electrocatalysts are applied in an alkaline electrolyzer driven by a commercial polycrystalline solar cell. It achieves electrolysis efficiency of 64.4% at 65 mA cm-2under sun irradiation of 50 mW cm-2. This practical application shows the promising prospect of low-cost and high-efficiency sustainable hydrogen production from combination of solar cells with high-performance noble metal free electrocatalysts.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Zixu
authors.initials: Z
authors.lastname: Tao
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Teng
authors.initials: T
authors.lastname: Wang
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Jie
authors.identifier: http://orcid.org/0000-0003-1817-6357
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Xingguo
authors.initials: X
authors.lastname: Li
keywords: electrocatalysis; hydrogen evolution; metal−organic frameworks; oxygen evolution; water splitting