Two‐dimensional covalent organic frameworks (2D‐COFs) have emerged as attractive platforms for solar‐to‐chemical energy conversion. In this study, we have implemented a gradient heating strategy to synthesize a sp2‐carbon‐linked triazine‐based COF, COF‐JLU100, exhibiting high crystallinity, large surface area, good durability and carrier mobility for solar‐driven photocatalytic hydrogen evolution. The Pt‐doped COF‐JLU100 demonstrated a high hydrogen evolution rate of over 100 000 μmol g−1 h−1 for water splitting under visible‐light illumination (λ>420 nm). Experimental and theoretical studies corroborate that the cyano‐vinylene segments in COF‐JLU100 extend the π‐delocalization and enable fast charge transfer and separation rates as well as good dispersion in water. Moreover, COF‐JLU100 can be prepared by low‐cost and easily available monomers and has excellent stability, which is desirable for practical solar‐driven hydrogen production.

Two-dimensional covalent−organic frameworks (2D COFs) have recently emerged as great prospects for their applications as new photocatalytic platforms in solarto-hydrogen conversion; nevertheless, their inefficient solar energy capture and fast charge recombination hinder the improvement of photocatalytic hydrogen production performance. Herein, two photoactive three-component donor−π−acceptor (TCDA) materials were constructed using a multicomponent synthesis strategy by introducing electrondeficient triazine and electron-rich benzotrithiophene moieties into frameworks through sp 2 carbon and imine linkages, respectively. Compared with two-component COFs, the novel TCDA-COFs are more convenient in regulating the inherent photophysical properties, thereby realizing outstanding photocatalytic activity for hydrogen evolution from water. Remarkably, the first sp 2 carbon-linked TCDA-COF displays an impressive hydrogen evolution rate of 70.8 ± 1.9 mmol g −1 h −1 with excellent reusability in the presence of 1 wt % Pt under visible-light illumination (420−780 nm). Utilizing the combination of diversified spectroscopy and theoretical prediction, we show that the full π-conjugated linkage not only effectively broadens the visible-light harvesting of COFs but also enhances charge transfer and separation efficiency.

The application of electrochemical energy storage materials to capacitive deionization (CDI), a low‐cost and energy‐efficient technology for brackish water desalination, has recently been proven effective in solving problems of traditional CDI electrodes, i.e., low desalination capacity and incompatibility in high salinity water. However, Faradaic electrode materials suffer from slow salt removal rate and short lifetime, which restrict their practical usage. Herein, a simple strategy is demonstrated for a novel tubular‐structured electrode, i.e., polyaniline (PANI)‐tube‐decorated with Prussian blue (PB) nanocrystals (PB/PANI composite). This composite successfully combines characteristics of two traditional Faradaic materials, and achieves high performance for CDI. Benefiting from unique structure and rationally designed composition, the obtained PB/PANI exhibits superior performance with a large desalination capacity (133.3 mg g−1 at 100 mA g−1), and ultrahigh salt‐removal rate (0.49 mg g−1 s−1 at 2 A g−1). The synergistic effect, interfacial enhancement, and desalination mechanism of PB/PANI are also revealed through in situ characterization and theoretical calculations. Particularly, a concept for recovery of the energy applied to CDI process is demonstrated. This work provides a facile strategy for design of PB‐based composites, which motivates the development of advanced materials toward high‐performance CDI applications.