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Layer‐stacking behaviors are crucial for two‐dimensional covalent organic frameworks (2D COFs) to define their pore structure, physicochemical properties, and functional output. So far, fine control over the stacking mode without complex procedures remains a grand challenge. Herein, we proposed a "key‐cylinder lock mimic" strategy to synthesize 2D COFs with a tunable layer‐stacking mode by taking advantage of ionic liquids (ILs). The staggered (AB) stacking (unlocked) COFs were exclusively obtained by incorporating ILs of symmetric polarity and matching molecular size; otherwise, commonly reported eclipsed (AA) stacking (locked) COFs were observed instead. Mechanistic study revealed that AB stacking was induced by a confined interlocking effect (CIE) brought by anions and bulky cations of the ILs inside pores ("key" and "cylinder", respectively). Excitingly, this strategy can speed up production rate of crystalline powders (e.g. COF‐TAPT‐Tf@BmimTf2N in merely 30 minutes) under mild reaction conditions. This work highlights the enabling role of ILs to tailor the layer stacking of 2D COFs and promotes further exploration of their stacking mode‐dependant applications. [ABSTRACT FROM AUTHOR]

Constructing photocatalyst systems to functionalize the inert C−H bonds has attracted extensive research interest. However, purposeful modulation of interfacial charge transfer in heterostructures remains a challenge, as it usually suffers from sluggish kinetics. Reported herein is an easy strategy to construct the heteroatom‐induced interface for developing the titanium‐organic frameworks (MOF‐902) @ thiophene‐based covalent triazine frameworks (CTF‐Th) nanosheets S‐scheme heterojunctions with controllable oxygen vacancies (OVs). Specifically, Ti atoms were first anchored onto the heteroatom site of CTF‐Th nanosheets, and then grown into MOF‐902 via an interfacial Ti−S linkage, generating OVs. Using in situ X‐ray photoelectron spectroscopy (XPS), extended X‐ray absorption fine structure (EXAFS) spectroscopy and density functional theory (DFT) calculations, the enhanced interfacial charge separation and transfer induced by moderate OVs in the pre‐designed S‐scheme nanosheets was validated. The heterostructures exhibited an improved efficiency in photocatalytic C3‐acylation of indoles under mild conditions with a yield 8.2 times larger than pristine CTF‐Th or MOF‐902 and enabled an extended scope of substrates (15 examples). This performance is superior to state‐of‐the‐art photocatalyst and can be retained, without significant loss, after 12 consecutive cycles. [ABSTRACT FROM AUTHOR]

Herein we introduce a straightforward, low cost, scalable, and technologically relevant method to manufacture an all-carbon, electroactive, nitrogen-doped nanoporous-carbon/carbon-nanotube composite membrane, dubbed 'HNCM/CNT'. The membrane is demonstrated to function as a binder-free, high-performance gas diffusion electrode for the electrocatalytic reduction of CO2 to formate. The Faradaic efficiency (FE) for the production of formate is 81 %. Furthermore, the robust structural and electrochemical properties of the membrane endow it with excellent long-term stability. [ABSTRACT FROM AUTHOR]

CO2 capture is a pressing global environmental issue that drives scientists to develop creative strategies for tackling this challenge. The concept in this contribution is to produce site-specific nitrogen doping in microporous carbon fibers. Following this approach a carbon/carbon heterojunction is created by using a poly(ionic liquid) (PIL) as a 'soft' activation agent that deposits nitrogen species exclusively on the surface of commercial microporous carbon fibers. This type of carbon-based biphasic heterojunction amplifies the interaction between carbon fiber and CO2 molecule for unusually high CO2 uptake and resistive sensing. [ABSTRACT FROM AUTHOR]

The superior physical properties of carbon nanotubes (CNTs) have led to their broad application. Intrinsically, CNTs tend to agglomerate from hydrophobic interactions, which is highly undesirable for solution processing and device fabrication. Commonly, a stabilizer consisting of organic surfactants or polymers is used to disperse CNTs. Recently, we synthesized nitrogen-doped carbon hollow nanospheres (25-90 nm), termed carbon 'nanobubbles'. They bear superior dispersability in water and distinctive graphitic order. Herein, we describe the nanobubble-assisted dispersion of CNTs in aqueous solution upon sonication. This process relies on the π-π interaction between the two aromatic carbon nanostructures, which can process their carbon mixture in water into conductive filter membranes, ink, and discs. This stabilization can be extended to other aromatic carbons. In addition, the π-π interaction may create a new type of carbon p-n junction that can be used to improve charge separation. [ABSTRACT FROM AUTHOR]