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Atomically dispersed Ru-Cu dual-atom catalysts (DACs) with asymmetric coordination are critical for sustainable ammonia production via electrochemical nitrate reduction (NO 3 RR), but their rational synthesis remains challenging. Here, we report a pulsed discharge strategy that injects a microsecond pulse current into ruthenium (Ru) and copper (Cu) precursors supported by nitrogen-doped graphene aerogels (NGA). The atomically dispersed Ru and Cu dual atoms anchor onto nanopore defects of NGA (RuCu DAs/NGA) through explosive decomposition of the metal salt nanocrystals. The catalyst achieves 95.7% Faraday efficiency and 3.1 mg h −1 cm −2 NH 3 yield at −0.4 V vs. RHE. In situ studies reveal an asymmetric RuN 2 -CuN 3 active-site dynamic evolution during NO 3 RR. Density functional theory calculations demonstrate that asymmetric RuN 2 CuN 3 /C structure synergistically optimizes intermediate adsorption and reduces energy barriers of key steps. The pulsed discharge enables ultrafast synthesis of various DACs (e.g., PtCu, AgCu, PdCu, FeCu, CoCu, NiCu) with tailored coordination environments, offering a general-purpose strategy for the precise preparation of atomically dispersed dual-atom catalysts, which are traditionally challenging to synthesize. Nitrate electroreduction to ammonia offers a sustainable route, but designing efficient catalysts remains challenging. Here, the authors develop a pulsed discharge strategy to synthesize dual atom catalysts with asymmetric active sites, achieving high ammonia production efficiency and stability.

By creating nanoscale pores in a layer of graphene, it could be used as an effective separation membrane due to its chemical and mechanical stability, its flexibility and, most importantly, its one-atom thickness. Theoretical studies have indicated that the performance of such membranes should be superior to state-of-the-art polymer-based filtration membranes, and experimental studies have recently begun to explore their potential. Here, we show that single-layer porous graphene can be used as a desalination membrane. Nanometre-sized pores are created in a graphene monolayer using an oxygen plasma etching process, which allows the size of the pores to be tuned. The resulting membranes exhibit a salt rejection rate of nearly 100% and rapid water transport. In particular, water fluxes of up to 10 6  g m −2  s −1 at 40 °C were measured using pressure difference as a driving force, while water fluxes measured using osmotic pressure as a driving force did not exceed 70 g m −2  s −1  atm −1 . An oxygen plasma etching process can be used to create a nanoporous graphene layer that can efficiently desalinate water.

The intrinsic defects in reduced graphene oxide (rGO) formed during reduction processes can act as nanopores, making rGO a promising ultrathin-film membrane candidate for separations. To assess the potential of rGO for such applications, molecular dynamics techniques are employed to understand the defect formation in rGO and their separation performance in water desalination and natural gas purification. We establish the relationship between rGO synthesis parameters and defect sizes, resulting in a potential means to control the size of nanopores in rGO. Furthermore, our results show that rGO membranes obtained under properly chosen synthesis conditions can achieve effective separations and provide significantly higher permeate fluxes than currently available membranes. Ultrathin-film nanoporous membranes promise low-cost and high-performance separation for applications such as water desalination and the purification of natural gas. Here, the authors adopt a molecular dynamics approach to assess the potential of reduced grapheme oxide as such a material.

Electronic and photonic devices based on graphene have unique properties, leading to outstanding performance figures of merit. Mastering the integration of this unconventional material into an established semiconductor fabrication line represents a critical step towards commercialization.

The direct growth of high-quality, large single-crystalline domains of graphene on a dielectric substrate is of vital importance for applications in electronics and optoelectronics. Traditionally, graphene domains grown on dielectrics are typically only ~1 μm with a growth rate of ~1 nm min −1 or less, the main reason is the lack of a catalyst. Here we show that silane, serving as a gaseous catalyst, is able to boost the graphene growth rate to ~1 μm min −1 , thereby promoting graphene domains up to 20 μm in size to be synthesized via chemical vapour deposition (CVD) on hexagonal boron nitride ( h -BN). Hall measurements show that the mobility of the sample reaches 20,000 cm 2  V −1  s −1 at room temperature, which is among the best for CVD-grown graphene. Combining the advantages of both catalytic CVD and the ultra-flat dielectric substrate, gaseous catalyst-assisted CVD paves the way for synthesizing high-quality graphene for device applications while avoiding the transfer process. The growth of high-quality graphene directly on to dielectric substrates is of key importance for future electronic and optoelectronic applications. Here, the authors use silane-catalysed chemical vapour deposition to fabricate large graphene sheets, up to 20 μm in size, on hexagonal boron nitride.

The large-scale production of graphene aimed at industrial applications has grown significantly in the past few years, especially since many companies in China have entered the market.

Graphene can be transformed from a semimetal into a semiconductor if it is confined into nanoribbons narrower than 10 nm with controlled crystallographic orientation and well-defined armchair edges. However, the scalable synthesis of nanoribbons with this precision directly on insulating or semiconducting substrates has not been possible. Here we demonstrate the synthesis of graphene nanoribbons on Ge(001) via chemical vapour deposition. The nanoribbons are self-aligning 3° from the Ge〈110〉 directions, are self-defining with predominantly smooth armchair edges, and have tunable width to <10 nm and aspect ratio to >70. In order to realize highly anisotropic ribbons, it is critical to operate in a regime in which the growth rate in the width direction is especially slow, <5 nm h −1 . This directional and anisotropic growth enables nanoribbon fabrication directly on conventional semiconductor wafer platforms and, therefore, promises to allow the integration of nanoribbons into future hybrid integrated circuits. Semiconducting armchair graphene nanoribbons with sub-10 nm width are of great technological importance but yet to realize. Here, the authors report growth of such nanoribbons on germanium and controlled crystallographic orientation and well-defined armchair edges are obtained.

Nanographenes, finite models of graphene sheets, are endowed with intriguing optical, electronic, and spintronic features. So-called heteroatom-doping, where one or more carbon is replaced by non-carbon light atoms has been proved effective in tuning the properties of nanographenes. Here we extend the concept of heteroatom nanographene doping to include metal centers. The method employed involves the use of a dipyrromethene fragment as an auxiliary ligand that is directly linked to the bay area of the model nanographene hexa-peri-hexabenzocoronene (HBC) to give a dipyrromethene-fused nanographene-type hybrid ligand (HBCP). HBCP has a corrole-like trianionic core that is capable of coordinating group 11 metal cations, including trivalent Cu, Ag and Au. These cations are introduced into the cavity with atomic precision to give metal complexes (HBCP-M; M = Cu, Ag, Au). The electronic structure and photophysical properties of HBCP and its metal complexes are investigated by steady-state and fs-transient spectroscopies, as well as DFT calculations. The ligand and metal complexes are also characterized via single crystal X-ray diffraction analyses. This work paves the way towards the precise metal doping of nanographenes within the carbon network, as opposed to the synthetic appendage of an independent chelating group, such as a fused tetrapyrrolic moiety. Nanographenes, finite models of graphene sheets, are endowed with intriguing optical, electronic, and spintronic features which can be tuned by replacing carbon via heteroatom-doping. Here the authors extend the concept of heteroatom nanographene doping to include metal centers.

Two-dimensional materials show a variety of promising properties, and controlling their growth is an important aspect for practical applications. To this end, active species such as hydrogen and oxygen are commonly introduced into reactors to promote the synthesis of two-dimensional materials with specific characteristics. Here, we demonstrate that fluorine can play a crucial role in tuning the growth kinetics of three representative two-dimensional materials (graphene, hexagonal boron nitride and WS 2 ). When growing graphene by chemical vapour deposition on a copper foil, fluorine released from the decomposition of a metal fluoride placed near the copper foil greatly accelerates the growth of the graphene (up to a rate of ~200 μm s −1 ). Theoretical calculations show that it does so by promoting decomposition of the methane feedstock, which converts the endothermic growth process to an exothermic one. We further show that the presence of fluorine also accelerates the growth of two-dimensional hexagonal boron nitride and WS 2 . Active species such as hydrogen and oxygen are commonly introduced into reactors to control the growth of two-dimensional materials. Now, the presence of fluorine—released by the decomposition of a metal fluoride sheet—has also been shown to modulate the growth kinetics of graphene, h-BN and WS 2 .

Zig-zag nanographenes are promising candidates for the applications in organic electronics due to the electronic properties induced by their periphery. However, the synthetic access to these compounds remains virtually unexplored. There is a lack in efficient and mild strategies origins in the reduced stability, increased reactivity, and low solubility of these compounds. Herein we report a facile access to pristine zig-zag nanographenes, utilizing an acid-promoted intramolecular reductive cyclization of arylaldehydes, and demonstrate a three-step route to nanographenes constituted of angularly fused tetracenes or pentacenes. The mild conditions are scalable to gram quantities and give insoluble nanostructures in close to quantitative yields. The strategy allows the synthesis of elusive low bandgap nanographenes, with values as low as 1.62 eV. Compared to their linear homologues, the structures have an increased stability in the solid-state, even though computational analyses show distinct diradical character. The structures were confirmed by X–ray diffraction or scanning tunneling microscopy. Nanographenes with zig-zag peripheries are expected to have unique electronic properties, but their application in organic electronics has been curbed by their difficult synthesis. Here, the authors develop a facile route to zig-zag nanographenes based on a key dehydrative π-extension reaction.