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Transition metal dichalcogenides (TMDs) are recognized as greatly promising substitutes for noble-metal-based catalysts for hydrogen evolution reaction (HER). The hybrids containing Co 3 S 4 @MoS 2 components demonstrate excellent electrocatalytic activity of HER. However, the more sustainable photocatalytic HER of two-dimensional (2D) Co 3 S 4 @MoS 2based materials remain scarce. In this study, Cu 0.9 Co 2.1 S 4 @MoS 2 composites were easily synthesized in situ by using bimetallic (Cu/Co) metal−organic frameworks (MOFs) as precursors through hydrothermal reaction; without extra precious metal and semiconductor as co-catalyst, the MoS 2 -content-optimized Cu 0.9 Co 2.1 S 4 @MoS 2 efficiently catalyzed hydrogen production at a rate of 40156 μmol h −1 g −1 (with a TON of 109) in aqueous solution containing eosin Y under visible light. The developed strategy of homogeneously alloyed MOFs as precursors caused adequate hybridization of the object material with homogeneous Cu-doping in Co 3 S 4 lattice, resulting in abundant interfaces and active sites as well as the low resistance of electron transfer, which thus considerably enhances photcatalytic HER performance, compared with undoped Co 3 S 4 @MoS 2 . HER mechanism was further elucidated by fluorescence spectroscopy, fluorescence lifetime test, impedance spectra, and photocurrent response measurements as well as control experiments.

Synthesizing large‐area free‐standing covalent organic framework (COF) films is of vital importance for their applications but is still a big challenge. Herein, we reported the synthesis of large metalloporphyrin‐based COF films and their applications for oxygen electrocatalysis. The reaction of meso‐benzohydrazide‐substituted metal porphyrins with tris‐aldehyde linkers afforded free‐standing COF films at the liquid‐air interface. These films can be scaled up to 3000 cm2 area and display great mechanical stability and structural integrity. Importantly, the Co‐porphyrin‐based films are efficient for electrocatalytic O2 reduction and evolution reactions. A flexible, all‐solid‐state Zn‐air battery was assembled using the films and showed high performance with a charge–discharge voltage gap of 0.88 V at 1 mA cm−2 and high stability under bent conditions (0° to 180°). This work thus presents a strategy to synthesize functionalized COF films with high quality for uses in flexible electronics.