Novel MOF-derived hexagonal starfish-shaped hollow prismatic cone-loaded metal complexes for electrocatalytic water decomposition study

Abstract

Exploring efficient and stable bifunctional electrocatalysts for oxygen evolution reaction/hydrogen evolution reaction (OER/HER) is an urgent need and challenge for sustainable energy. Non-noble metal-based catalysts have attracted more and more attention due to their low cost and high catalytic performance. The construction of heterostructures is considered to be one of the most promising strategies for revealing the efficient performance for OER and HER. As a result, we prepared a nanomaterial catalyst based on the combination of three non-precious metals, which were simultaneously used for efficient OER, HER and integral water splitting techniques. We first prepared a very novel hollow hexagram star-shaped metal-organic frameworks (MOFs) by a one-step hydrothermal method, then used it as the substrate material, introduced Mo6+ and Fe3+ through ion exchange reaction, and finally formed a composite system of Co3Fe7 and Mo2C through high-temperature calcination, and the product with hexagonal starfish morphology was named as hexagonal starfish-shaped hollow prismatic cone-loaded metal complexes (HSHP-Mo2C/Co3Fe7). Taking advantage of the synergistic effect of the Co3Fe7 site and the Mo2C site, HSHP-Mo2C/Co3Fe7 not only exhibit excellent OER and HER properties, but also exhibit good stability and durability. Specifically, the optimal catalyst HSHP-Mo2C/Co3Fe7-1 shows a Tafel slope of only 46mV dec-1 for OER and 99mV dec-1 fort HER, an overpotential of only 324 and 371mV and the stability is even up to 60h. This work provides a promising strategy for the development of cost-effective, efficient and stable catalysts for energy area.