Covalent organic frameworks (COFs) have emerged as an important class of organic semiconductors and photocatalysts for the hydrogen evolution reaction (HER)from water.T oo ptimize their photocatalytic activity,t ypically the organic moieties constituting the frameworks are considered and the most suitable combinations of them are searched for. However,t he effect of the covalent linkage between these moieties on the photocatalytic performance has rarely been studied. Herein, we demonstrate that donor-acceptor (D-A) type imine-linked COFs can produce hydrogen with ar ate as high as 20.7 mmol g À1 h À1 under visible light irradiation, upon protonation of their imine linkages.Asignificant red-shift in light absorbance,largely improved charge separation efficiency,a nd an increase in hydrophilicity triggered by protonation of the Schiff-base moieties in the imine-linked COFs,a re responsible for the improved photocatalytic performance.

No abstract

No abstract

The interaction between water molecules and surfaces in porous systems is of huge importance in various fields including but not limited to catalysis, adsorption, and the storage or conversion of...

The water splitting for hydrogen energy is largely constrained by sluggish anodic oxygen evolution reaction (OER). Cobalt oxide, one of the most promising non‐noble metal catalysts for OER, can exhibit highly enhanced catalytic OER activity when deposited on gold substrates. However, it still remains challenging to develop efficient Au/Co3O4 catalysts that can maximize the catalytic activity with the minimum use of gold. Here is reported a simple leaching derived synthesis of atomically dispersed/clustered gold on mesoporous cobalt oxides as highly efficient catalysts for OER. With greatly lowered gold contents <1 wt%, the catalyst shows twice as much current density and Au normalized activity than mesoporous cobalt oxide at 400 mV overpotential. The present work provides a simple synthesis route toward atomically dispersed/clustered gold supported catalysts, which can be extended to the development of a wide variety of efficient nanocatalysts that can be designed for specific applications.