Metal-Organic Powder Thermochemical Solid-Vapor Architectonics Towards Gradient Hybrid Monolith with Combined Structure-Function Features

Abstract

Direct manufacturing from powder to final component is of great significance for industry. However, it remains a challenge to develop a one-pot “powder to product” strategy to produce gradient hybrid component with combined structure-function advantages. In this work, we report a metal-organic powder thermochemical solid-vapor architectonics to direct zeolitic imidazolate framework powder into gradient cobalt/carbon monolith with atomically doped nitrogen, encapsulated cobalt nanoparticles, nanotubes arrays, and well-interconnected grains. The in situ generated H 2 vapor (non-uniform distribution) and Co nanoparticles (uniformly distributed) combines a chemical vapor deposition/growth and a solids-state welding together, leading to formation of the unique gradient monolith. The gradient carbon monolith is of good mechanical stability, therefore is directly used as a freestanding working electrode for hydrogen evolution reaction (HER) in a seawater battery. This catalyst shows a low overpotential of 84 mV at a current density of 10 mA cm-2 as well as good stability for HER at a constant overpotential of 200 mV for 5 h. Furthermore, a stable power generation of over 168 h in seawater has been realized.