Non-Volatile Electrolyte-Gated Transistors Based on Graphdiyne/MoS2 with Robust Stability for Low-Power Neuromorphic Computing and Logic-In-Memory

Artificial synapses are the key building blocks for low-power neuromorphic computing that can go beyond the constraints of von Neumann architecture. In comparison with two-terminal memristors and three-terminal transistors with filament-formation and charge-trapping mechanisms, emerging electrolyte-gated transistors (EGTs) have been demonstrated as a promising candidate for neuromorphic applications due to their prominent analog switching performance. Here, a novel graphdiyne (GDY)/MoS₂-based EGT is proposed, where an ion-storage layer (GDY) is adopted to EGTs for the first time. Benefitting from this Li-ion-storage layer, the GDY/MoS₂-based EGT features a robust stability (variation < 1% for over 2000 cycles), an ultralow energy consumption (50 aJ µm⁻²), and long retention characteristics (>10⁴ s). In addition, a quasi-linear conductance update with low noise (1.3%), an ultrahigh G_max/G_min ratio (10³), and an ultralow readout conductance (<10 nS) have been demonstrated by this device, enabling the implementation of the neuromorphic computing with near-ideal accuracies. Moreover, the non-volatile characteristics of the GDY/MoS₂-based EGT enable it to demonstrate logic-in-memory functions, which can execute logic processing and store logic results in a single device. These results highlight the potential of the GDY/MoS₂-based EGT for next-generation low-power electronics beyond von Neumann architecture.     

An Ultrafast Nonvolatile Memory with Low Operation Voltage for High-Speed and Low-Power Applications

Memory plays a vital role in modern information society. High-speed and low-power nonvolatile memory is urgently demanded in the era of big data. However, ultrafast nonvolatile memory with nanosecond-timescale operation speed and long-term retention is still unavailable. Herein, an ultrafast nonvolatile memory based on van der Waals heterostructure is proposed, where a charge-trapping material, graphdiyne (GDY), serves as the charge-trapping layer. With the band-engineered heterostructure and excellent charge-trapping capability of GDY, charges are directly injected into the GDY layer and are persistently captured by the trapping sites in GDY, which result in an ultrafast writing speed (8 ns), a low operation voltage (30 mV), and a long retention time (over 10⁴ s). Moreover, a high on/off ratio of 10⁶ is demonstrated by this memory, which enables the achievement of multibit storage with 6 discrete storage levels. This device fills the blank of ultrafast nonvolatile memory technology, which makes it a promising candidate for next-generation high-speed and low-power-consumption nonvolatile memory.     

Graphdiyne‐Supported NiCo2S4 Nanowires: A Highly Active and Stable 3D Bifunctional Electrode Material

The oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and overall water splitting are major energy and chemical conversion efforts. Progress in electrocatalytic reactions have shown that the future is limitless in many fields. However, it is urgent to develop efficient electrocatalysts. Here, the first graphdiyne‐supported efficient and bifunctional electrocatalyst is reported using 3D graphdiyne foam as scaffolds, and NiCo₂S₄ nanowires as building blocks (NiCo₂S₄ NW/GDF). NiCo₂S₄ NW/GDF exhibits outstanding catalytic activity and stability toward both OER and HER, as well as overall water splitting in alkaline media. Remarkably, it enables a high‐performance alkaline water electrolyzer with 10 and 20 mA cm^?2 at very low cell voltages of 1.53 and 1.56 V, respectively, and remarkable stability over 140 h of continuous electrolysis operation at 20 mA cm^?2. The results indicate that this catalyst has a bifunction that overcomes all reported bifunctional, nonprecious‐metal‐based ones.     

A Delicately Designed Sulfide Graphdiyne Compatible Cathode for High‐Performance Lithium/Magnesium–Sulfur Batteries

Novel sulfur cathodes hold the key to the development of metal–sulfur batteries, the promising candidate of next‐generation high‐energy‐storage systems. Herein, a fascinating sulfur cathode based on sulfide graphdiyne (SGDY) is designed with a unique structure, which is composed of a conducting carbon skeleton with high Li⁺ mobility and short sulfur energy‐storing unites. The SGDY cathode can essentially avoid polysulfide dissolution and be compatible with commercially available carbonate‐based electrolytes and Grignard reagent‐based electrolytes (all phenyl complex (APC) type electrolytes). Both the assembled Li–S and Mg–S batteries exhibit excellent electrochemical performances including large capacity, superior rate capability, high capacity retention, and high Coulombic efficiency. More importantly, this is the first implementation case of a reliable Mg–S system based on nucleophilic APC electrolytes.     

Diatomite‐Templated Synthesis of Freestanding 3D Graphdiyne for Energy Storage and Catalysis Application

Graphdiyne (GDY), a new kind of two‐dimensional (2D) carbon allotropes, has extraordinary electrical, mechanical, and optical properties, leading to advanced applications in the fields of energy storage, photocatalysis, electrochemical catalysis, and sensors. However, almost all reported methods require metallic copper as a substrate, which severely limits their large‐scale application because of the high cost and low specific surface area (SSA) of copper substrate. Here, freestanding three‐dimensional GDY (3DGDY) is successfully prepared using naturally abundant and inexpensive diatomite as template. In addition to the intrinsic properties of GDY, the fabricated 3DGDY exhibits a porous structure and high SSA that enable it to be directly used as a lithium‐ion battery anode material and a 3D scaffold to create Rh@3DGDY composites, which would hold great potential applications in energy storage and catalysts, respectively.     

Low‐Temperature Growth of All‐Carbon Graphdiyne on a Silicon Anode for High‐Performance Lithium‐Ion Batteries

In situ weaving an all‐carbon graphdiyne coat on a silicon anode is scalably realized under ultralow temperature (25 °C). This economical strategy not only constructs 3D all‐carbon mechanical and conductive networks with reasonable voids for the silicon anode at one time but also simultaneously forms a robust interfacial contact among the electrode components. The intractable problems of the disintegrations in the mechanical and conductive networks and the interfacial contact caused by repeated volume variations during cycling are effectively restrained. The as‐prepared electrode demostrates the advantages of silicon regarding capacity (4122 mA h g^?1 at 0.2 A g^?1) with robust capacity retention (1503 mA h g^?1) after 1450 cycles at 2 A g^?1, and a commercial‐level areal capacity up to 4.72 mA h cm^?2 can be readily approached. Furthermore, this method shows great promises in solving the key problems in other high‐energy‐density anodes.     

Atomic Pd on Graphdiyne/Graphene Heterostructure as Efficient Catalyst for Aromatic Nitroreduction

With the maximum atom‐utilization efficiency, single atom catalysts (SACs) have attracted great research interest in catalysis science recently. To address the following key challenges for the further development of SACs: i) how to stabilize and avoid the aggregation of SACs, ii) how to enhance the specific surface area and conductivity of supports, and iii) how to achieve scalable mass production with low cost, a SAC consisting of single Pd atoms anchored on well‐designed graphdiyne/graphene (GDY/G) heterostructure (Pd₁/GDY/G) is synthesized. Pd₁/GDY/G exhibits high catalytic performance, as demonstrated by the reduction reaction of 4‐nitrophenol. Furthermore, density functional theory calculation indicates that graphene in the GDY/G heterostructure plays a key role in the enhancement of catalytic efficiency owing to the electron transfer process, deriving from the gap between the Fermi level of graphene and the conduction band minimum of GDY. The GDY/G heterostructure is a promising support for the preparation of extremely efficient and stable SACs, which can be used in a broad range of future industrial reactions.     

石墨炔掺杂聚合物太阳能器件性能的研究

制备了石墨炔掺杂poly(3-hexylthiophene):[6,6] -phenyl-C61-buytyric acid methyl ester活性层的聚合物光伏器件.研究了石墨炔不同掺杂比例对光伏器件的短路电流及开路电压的影响.结果表明:石墨炔良好的电荷传输特性及二维平面结构可以改善活性层的互穿网络结构,增加电荷收集和传输的通道,从而提高器件的短路电流.在2.5％的掺杂比例下,短路电流提高了1.4 mA/cm2,能量转化效率提高了 35％,并且对不同的退火温度和退火时间经行了研究,发现最佳的退火温度为150℃.     

In Situ Coating Graphdiyne for High-Energy-Density and Stable Organic Cathodes

The preparation of organic small-molecule cathodes is simple and low-cost; however, their low conductivity and molecular dissolution are two key issues that mean their energy density and power performance are far lower than those of inorganic batteries, thus hindering their practical application. To develop an effective coating technology is the key to obtain high-performance organic batteries. A general method of in situ weaving all-carbon graphdiyne nanocoatings is demonstrated. The graphdiyne can be conformally weaved on organic particles under mild conditions so that the conductivity is increased and the dissolution is suppressed. After weaving graphdiyne nanocoat, the active mass of the small-molecule organic cathodes rise to 93%, thus delivering a higher energy density of 310 W h kg⁻¹ than previously reported, and the power performance and long-term stability are greatly improved. Additionally, this method shows great potential to become the crucial technology for fabricating organic batteries with energy density close to prevailing lithium-ion batteries.