Metal-organic framework derived CoSe2 nanoparticles anchored on carbon fibers as bifunctional electrocatalysts for efficient overall water splitting

The development of efficient,low-cost,stable,non-noble-metal electrocatalysts for water splitting,particularly those that can catalyze both the hydrogen evolution reaction (HER) at the cathode and oxygen evolution reaction (OER) at the anode,is a challenge.We have developed a facile method for synthesizing CoSe2 nanoparticles uniformly anchored on carbon fiber paper (CoSe2/CF) via pyrolysis and selenization of in situ grown zeolitic imidazolate framework-67 (ZIF-67).CoSe2/CF shows high and stable catalytic activity in both the HER and OER in alkaline solution.At a low cell potential,i.e.,1.63 V,a water electrolyzer equipped with two CoSe2/CF electrodes gave a water-splitting current of 10 mA.cm-2.At a current of 20 mA.cm-2,it can operate without degradation for 30 h.This study not only offers a cost-effective solution for water splitting but also provides a new strategy for developing various catalytic nanostructures by changing the metal-organic framework precursors.