Temperature‐Mediated Engineering of Graphdiyne Framework Enabling High‐Performance Potassium Storage

Graphdiyne (GDY), an emerging type of carbon allotropes, possesses fascinating electrical, chemical, and mechanical properties to readily spark energy applications in the realm of Li‐ion and Na‐ion batteries. Nevertheless, rational design of GDY architectures targeting advanced K‐ion storage has rarely been reported to date. Herein, the first example of synthesizing GDY frameworks in a scalable fashion to realize superb potassium storage for high‐performance K‐ion battery (KIB) anodes is showcased. To begin with, first principles calculations provide theoretical guidances for analyzing the intrinsic potassium storage capability of GDY. Meanwhile, the specific capacity is predicted to be as high as 620 mAh g^?1, which is considerably augmented as compared with graphite (278 mAh g^?1). Experimental tests then reveal that prepared GDY framework indeed harvests excellent electrochemical performance as a KIB anode, achieving high specific capacity (≈505 mAh g^?1 at 50 mA g^?1), outstanding rate performance (150 mAh g^?1 at 5000 mA g^?1) and favorable cycling stability (a high capacity retention of over 90% after 2000 cycles at 1000 mA g^?1). Furthermore, kinetic analysis reveals that capacitive effect mainly accounts for the K‐ion storage, with operando Raman spectroscopy/ex situ X‐ray photoelectron spectroscopy identifying good electrochemical reversibility of GDY.     

Graphdiyne: A Brilliant Hole Accumulator for Stable and Efficient Planar Perovskite Solar Cells

Traditional carbon materials have demonstrated immense potential in perovskite solar cells (PSCs) owing to their superior electrical properties and environmental stability. Graphdiyne (GDY), as an emerging carbon allotrope, features uniformly distributed pores, endless design flexibility, and unique electronic character compared with traditional carbon materials. Herein, graphdiyne is introduced into the upper part of the perovskite (CH₃NH₃PbI₃) layer by utilizing a GDY‐containing antisolvent during the one‐step synthesis of perovskite. Intriguingly, GDY plays an essential role in hole accumulation and transportation because of its higher Fermi level than perovskite. As a result, the automatic separation of photogenerated carriers inside the perovskite film is achieved. Furthermore, the Schottky barrier formed on the interface between perovskite and GDY guarantees the unidirectional hole transport from perovskite to GDY, thereby benefiting further extraction to the hole transport layer. Consequently, GDY‐modified perovskite‐based planar PSCs exhibit a boosted J_sc of 24.21 mA cm^?2 and up to 19.6% power conversion efficiency owing to the increased efficient light utilization and charge extraction. The device with GDY modification exhibits less than 10% shrinkage after a month in ambience. Overall, this work demonstrates an easy method for the utilization of GDY to boost the charge extraction and environmental stability in PSCs.     

A Graphdiyne Oxide-Based Iron Sponge with Photothermally Enhanced Tumor-Specific Fenton Chemistry

Fenton reaction-mediated oncotherapy is an emerging strategy which uses iron ions to catalytically convert endogenous hydrogen peroxide into hydroxyl radicals, the most reactive oxygen species found in biology, for efficient cancer therapy. However, Fenton reaction efficiency in tumor tissue is typically limited due to restrictive conditions. One strategy to overcome this obstacle is to increase the temperature specifically at the tumor site. Herein, a tumor-targeting iron sponge (TTIS) nanocomposite based on graphdiyne oxide, which has a high affinity for iron is described. TTIS can accumulate in tumor tissue by decoration with a tumor-targeting polymer to enable tumor photoacoustic and magnetic resonance imaging. With its excellent photothermal conversion efficiency (37.5%), TTIS is an efficient photothermal therapy (PTT) agent. Moreover, the heat produced in the process of PTT can accelerate the release of iron ions from TTIS and simultaneously enhance the efficiency of the Fenton reaction, thus achieving a combined PTT and Fenton reaction-mediated cancer therapy. This work introduces a graphdiyne oxide-based iron sponge that exerts an enhanced antitumor effect through PTT and Fenton chemistry.     

On‐Surface Synthesis of Graphyne‐Based Nanostructures

The successful synthesis of stacking graphdiynes has stimulated numerous fascinating applications. However, it still remains challenging to prepare atomically precise 2D graphdiyne and other graphyne‐based structures. The development of on‐surface synthesis has contributed to many secondary graphyne‐based structures that are directive in fabricating extended graphyne networks. Herein, the recent progress concerning on‐surface synthesis of graphyne‐based nanostructures, especially atomically precise graphdiyne nanowires, is summarized.     

Rational Construction of Advanced Potassium Ion Diffusion and Storage Matrix

Developing new electrode materials with a regular channel for stable storage and diffusion of potassium (K) ions is crucial to alleviating the ubiquitous problems in K-ion batteries (KIBs) such as slow diffusion rate, huge volume expansion, and unstable interface by the large K ion radius. Herein, electrode material with a facile diffusion pathway, vast space for volume expansion, and good interfacial compatibility are found to be necessary. Fluoride graphdiyne (F-GDY) is illustrated for its expanded conductive skeleton, uniform structural pores, and well-distributed F atoms. First-principles computations and electrochemical characterizations reveal the high reversible capacity and cyclic stability for the instanced F-GDY electrode through the ultralow diffusion barrier, abundant exposed active sites, and stable KF-enriched solid electrolyte interphase film. The F-GDY anode exhibits a capacity of 320 mAh g⁻¹ at 50 mA g⁻¹, and 120 mAh g⁻¹ at 1000 mA g⁻¹ for 1800 cycles. These electrochemical performances of F-GDY anode are superior than those of many other carbon materials reported to date, providing us with a new insight into the design of an electrode for KIBs.     

Controlled Growth of MoS2 Nanosheets on 2D N‐Doped Graphdiyne Nanolayers for Highly Associated Effects on Water Reduction

The first utilization of nitrogen‐doped graphdiyne (NGDY) as an efficient catalytic promoter for hydrogen evolution reaction (HER) is reported. X‐ray powder diffraction and X‐ray photoelectron spectroscopy studies indicate the presence of strong interactions between NGDY and MoS₂, which should effectively facilitate the charge transport behavior and improvement of the HER kinetics. The creative hybridization of MoS₂ and NGDY endows such heterostructure with structural and compositional advantages for boosting the catalytic activity (low overpotential of 186 mV at 10 mA cm^?2 and Tafel slope of 63 mV dec^?1) and extraordinary stability (higher than all reported MoS₂‐based materials and even better than that of commercial Pt and almost all benchmarked electrocatalysts). All of the results not only demonstrate that NGDY can be used as an effective catalytic promoter for hydrogen production, but also provide new strategy for fabricating efficient water‐splitting electrodes.     

A Novel and Highly Efficient Photocatalyst Based on P25–Graphdiyne Nanocomposite

Titania nanoparticles (P25) are successfully chemically bonded with graphdiyne (GD) nanosheets by a facile hydrothermal treatment, to form a novel nanocomposite photocatalyst. The as‐prepared P25–GD nanocomposite exhibits higher photocatalytic activity for degrading methylene blue under UV irradiation than not only P25 and P25–carbon nanotube composite but also the current well‐known P25–graphene composite photocatalysts. Moreover, P25–GD also shows considerable visible‐light‐driven photocatalytic activity, since the formation of chemical bonds between P25 and GD effectively decreases the bandgap of P25 and extends its absorbable light range. The photocatalytic activity of P25–GD can be adjusted by changing the content of GD in composites and the optimized value is about 0.6 wt%. Such a nanocomposite photocatalyst might find potential application in a wide range of fields including air purification and waste water treatment.     

Graphdiyne Ultrathin Nanosheets for Efficient Water Splitting

Graphdiyne (GDY) is an emerging 2D carbon material that exhibits unusual structures and properties. Therefore, growing heterogeneous materials on the surface of GDY is very attractive to achieve efficient energy utilization. Here, a simple method for the controllable synthesis of ultrathin charge-transfer complexes (CTs) of nickel with terephthalic acid nanosheets on GDY is reported. This catalyst shows record-high oxygen evolution reaction (OER) activity with an overpotential of only 155 mV to deliver a current density of 10 mA cm⁻² in an alkaline electrolyte. Density functional theory calculations reveals that a strong p–d coupling effect in the GDY–CT interface region enhances the overall electronic activity, resulting in fast reversible redox-switching with a low electron-transfer barrier. Experimental characterization confirms that GDY plays a key role in modulating the morphological and electronic structures to accelerate the OER rate. These findings are expected to contribute to the design of more efficient catalysts for the realization of efficient hydrogen energy technologies.