Novel Bifunctional Nitrogen Doped Mos2/Cof-C4n Vertical Heterostructures for Electrocatalytic Her and Oer

Abstract

Highly active and earth-abundant catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) play vital roles in developing efficient water splitting to produce hydrogen fuels. Here, we reported a simple, facile and effective strategy to fabricate a completely new nitrogen doped MoS2/COF-C4N vertical heterojunction (N-MoS2/COF-C4N) as precious-metal-free bifunctional electrocatalysts for both HER and OER. Compared with commercial MoS2 and COF-C4N, the obtained vertical N-MoS2/COF-C4N catalyst showed enhanced HER with low overpotential of 106 mV at 10 mA cm-2, which is 6 times lower than commercial MoS2. The superior acidic HER activity, molecular mechanism and charge transfer characteristic of this vertical N-MoS2/COF-C4N was investigated experimentally and theoretically in detail. And its basic OER activity almost equals to that of COF-C4N with overpotential of 349 mV at 10 mA cm-2, which showed that in-situ growing method maintains the exposure of the C active sites to the greatest extent. The preparation and investigation for vertical N-MoS2/COF-C4N provide ideas and research basis for us to further explore a promising overall water splitting electrocatalysts.

Keywords: Vertical Heterostructures, Novel Nitrogen Doped MoS2/COF-C4N, Electrocatalytic HER, Electrocatalytic OER, In-situ Growing