25th Anniversary Article: 25 Years of Fullerene Research in Electron Transfer Chemistry

The past 25 years have served as a test bed for exploring the chemistry and physics, in general, and the electron transfer chemistry, in particular, of low‐dimensional carbon. Nevertheless, the new realm started with the advent of fullerenes, followed in chronological order by carbon nanotubes, and, more recently, by graphene. The major thrust of this Review article is to historically recap the versatility of fullerenes regarding the design, the synthesis, and the tests as an electroactive building block in photosynthetic reaction mimics, photovoltaics, and catalysis.     

Intramolecular Electron Transfers in Donor/Acceptor Linked Molecules Based on Endohedral Lanthanide Metallofullerenes

Chemical syntheses and intramolecular electron transferring behaviors in the electron donor/acceptor conjugates based on endohedral metallofullerenes, La₂@C₈₀ and La@C₈₂, are overviewed. A study on the photo-induced excited states of a La₂@C₈₀ derivative connected with an electron donor revealed the formation of a distinct radical ion pair state. A La@C₈₂ derivative linked with an electron donor demonstrated an unprecedented ion/anion pair state, and La₂@C₈₀ tethered with an acceptor showed a fullerene donor system, in which the fullerene acts as an electron donor. Using endohedral lanthanide metallofullerenes for intramolecular electron transferring systems opens a new door for developing novel molecular materials.     

金属氮化物富勒烯的研究现状

内嵌金属氮化物簇富勒烯的发现极大地扩展了内嵌富勒烯家族。内嵌金属氮化物富勒烯是一类将含有金属原子的氮化物(Mx-N,AxM3-x-N)包裹在富勒烯碳笼中的化合物,因其具有独特的分子结构和性质而受到人们广泛的研究和关注。阐述了合成金属氮化物富勒烯的方法,着重介绍了电弧法,探讨了氮源对电弧法合成金属氮化物富勒烯产量的影响,介绍了金属氮化物富勒烯常用的分离提纯方法,最后讨论了金属氮化物富勒烯的结构特点、性质和潜在应用。     

Studies on the Photocatalytic Electron Pooling of Graphene Oxide Hybrids Decorated with Electron Donor and Electron Acceptor Molecules

Photocatalytic behavior of a recently synthesized, single layer graphene oxide (SLGO) decorated with an electron donor, zinc phthalocyanine (ZnPc) and an electron acceptor, fulleropyrrolidine (C₆₀) donor-acceptor hybrid is demonstrated. Electron accumulation in the form of one-electron reduced product of methyl viologen was obtained in high yields in an electron pooling experiment involving the ZnPc-SLGO-C₆₀ hybrid and a sacrificial electron donor compared with control hybrids involving either ZnPc-SLGO or SLGO-C₆₀ hybrids. This novel property of ZnPc-SLGO-C₆₀ hybrid has been ascribed to the proximity effect offered by GO with covalently linked donor and acceptor entities on its surface. The present studies reveal that the ZnPc-SLGO-C₆₀ hybrid is a suitable catalyst for solar fuel production.     

醚/酯复合内给电子体Ziegler-Natta催化剂对丁烯-1聚合的影响

制备了5种含有不同内给电子体(乙二醇二甲醚,邻苯二甲酸二丁酯和三种二者不同比例复合内给电子体)的Mg-Cl2负载型丁烯-1聚合Ziegler-Natta(Z-N)催化剂,研究了复合和单一给电子体催化剂的相关性能。结果表明,复合内给电子体催化剂的活性有很大提高,对聚丁烯-1等规度影响较小;加入外给电子体后明显提高了聚合产物的等规度(由55.9%增加到84.5%),而且环己基甲基二甲氧基硅烷(CHMMS)更有利于等规度的提高;Al(i-Bu)3有利于聚丁烯-1等规度的提高,而AlEt3有利于催化活性的提高;复合内给电子体催化剂使聚丁烯-1的分子质量增大。     

Donor:Acceptor Janus Nanoparticle-Based Films as Photoactive Layers: Control of Assembly and Impact on Performance of Devices

Water-processable organic semiconductor nanoparticles (NPs) are considered promising materials for the next-generation of optoelectronic applications due to their controlled size, internal structure, and environmentally friendly processing. Reasonably, the controllable assembly of donor:acceptor (D:A) NPs on large areas, quality, and packing density of deposited films, as well as layer morphology, will influence the effectiveness of charge transfer at an interface and the final performance of designed optoelectronic devices.This work represents an easy and effective approach for designing self-assembled monolayers of D:A NPs. In this self-assembly procedure, the NP arrays are prepared on a large scale (2 × 2 cm²) at the air/water interface with controlled packing density and morphology. Due to the unique structure of individual D:A Janus particles and their assembled arrays, the Janus nanoparticle (JNP)-based device exhibits an 80% improvement of electron mobility and more balanced charge extraction compared to the conventional core–shell NP-based device. An outstanding performance of polymer solar cells with over 5% efficiency is achieved after post-annealing treatment of assembled arrays, representing one of the best results for NP-based organic photovoltaics. Ultimately, this work provides a new protocol for processing water-processable organic semiconductor colloids and future optoelectronic fabrication.     

聚合物在太阳能电池材料中的应用

综述了近年来聚合物在太阳能电池材料中的应用.对电子给体材料和受体材料两类聚合物材料进行详细的描述,并阐述了进一步发展的重点和前景.     

Creating Graphitic Carbon Nitride Based Donor‐π–Acceptor‐π–Donor Structured Catalysts for Highly Photocatalytic Hydrogen Evolution

Conjugated polymers with tailored donor–acceptor units have recently attracted considerable attention in organic photovoltaic devices due to the controlled optical bandgap and retained favorable separation of charge carriers. Inspired by these advantages, an effective strategy is presented to solve the main obstructions of graphitic carbon nitride (g‐C₃N₄) photocatalyst for solar energy conversion, that is, inefficient visible light response and insufficient separation of photogenerated electrons and holes. Donor‐π–acceptor‐π–donor polymers are prepared by incorporating 4,4′‐(benzoc 1,2,5 thiadiazole‐4,7‐diyl) dianiline (BD) into the g‐C₃N₄ framework (UCN‐BD). Benefiting from the visible light band tail caused by the extended π conjugation, UCN‐BD possesses expanded visible light absorption range. More importantly, the BD monomer also acts as an electron acceptor, which endows UCN‐BD with a high degree of intramolecular charge transfer. With this unique molecular structure, the optimized UCN‐BD sample exhibits a superior performance for photocatalytic hydrogen evolution upon visible light illumination (3428 µmol h^?1 g^?1), which is nearly six times of that of the pristine g‐C₃N₄. In addition, the photocatalytic property remains stable for six cycles in 3 d. This work provides an insight into the synthesis of g‐C₃N₄‐based D‐π–A‐π–D systems with highly visible light response and long lifetime of intramolecular charge carriers for solar fuel production.     

A High‐Efficiency Organic Solar Cell Enabled by the Strong Intramolecular Electron Push–Pull Effect of the Nonfullerene Acceptor

Besides broadening of the absorption spectrum, modulating molecular energy levels, and other well‐studied properties, a stronger intramolecular electron push–pull effect also affords other advantages in nonfullerene acceptors. A strong push–pull effect improves the dipole moment of the wings in IT‐4F over IT‐M and results in a lower miscibility than IT‐M when blended with PBDB‐TF. This feature leads to higher domain purity in the PBDB‐TF:IT‐4F blend and makes a contribution to the better photovoltaic performance. Moreover, the strong push–pull effect also decreases the vibrational relaxation, which makes IT‐4F more promising than IT‐M in reducing the energetic loss of organic solar cells. Above all, a power conversion efficiency of 13.7% is recorded in PBDB‐TF:IT‐4F‐based devices.     

An Inhomogeneous Grain Boundary Composition in Silicon Nitride Ceramics as Revealed by 300 kV Field Emission Analytical Electron Microscopy

The chemical compositions of the grain boundary phases of silicon nitride (Si₃N₄) ceramics containing additives of 1 mole% and 10 mole% of an equi-molar mixture of Y₂O₃ and Nd₂O₃ have been studied by 300 kV field emission analytical electron microscopy. The energy dispersive x-ray spectra (EDS) are obtained from both two-grains and triple-grain junctions, where an electron beam of about 0.5 nm in diameter is focused. The thickness of the intergranular thin film is found to be about 1 nm, whose value is almost the same between two samples. The sintering additives are highly enriched at the triple-grain junctions, while they are less concentrated at the two-grain junctions. It is also shown that the additives are distributed inhomogeneously within the triple-grain junctions. Based on the composition analysis among the grain boundaries, an inhomogeneous grain boundary composition model for the Si₃N₄ ceramics is proposed.