Search

Nanoparticles are presently considered to be high-potential additives in insulation materials. Surface modifiers can not only improve the compatibility between nanoparticles and natural ester but also enhance the insulation performance of the insulation liquid. In this work, a mixture of two natural ester insulation oils (rapeseed oil + palm fatty acid ester) doped with 3-aminopropyltriethoxysilane (KH550)-TiO2 nanoparticles was prepared, and a 56-day thermal aging experiment was implemented. Moreover, the molecular dynamics simulation was applied to investigate the improvement mechanism of the physicochemical and electrical properties from a microscopic perspective. The experimental results revealed that KH550-modified nano-TiO2 particles could reduce the generation of microwater and acidic substances during the aging process of the oil–paper insulation system, retard the degradation of the system, and improve the thermal stability and insulation performance. At the end of the thermal aging, a decrease of breakdown voltage by 7.3% and an increase of acid value by 17.3% were observed in the modified insulation oil. On the contrary, the pure insulation oil decreased the breakdown voltage by 26.96%, and the acid value increased by 28.38%. Furthermore, the molecular simulation results determined that KH550-TiO2 could combine with polar molecules through hydrogen bonds, adsorb polar molecules in insulation oil, prevent their diffusion into cellulose insulation paper, and delay the aging and decomposition of insulation paper. Therefore, the modified nanoparticles have remarkably enhanced the antithermal aging performance of the oil–paper insulation system, which provides a considerably greater application prospect for nanomodification insulation in liquid medium. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is one of the major air pollutants that may cause ecological imbalance and severe human disease. However, the removal of NO faces challenges of low efficiency, high energy consumption, and production of toxic NO 2 byproducts. Herein, we report an efficient *OOH intermediate-involved NO oxidation route with high NO 3 - selectivity via a gas phase photo-Fenton system. Fe single atoms (Fe SAs)-anchored NH 2 -UiO-66(Zr) (Fe SAs@NU) was synthesized. The five-coordinated Fe SAs undergo a transient structure reconstitution during the photo-Fenton process, which enables a novel heterolytic cleavage pathway of H 2 O 2 to derive specific ·OOH/·O 2 - radicals as reactive oxygen species. Therefore, a high NO (550 parts per billion) removal rate of 81% (NO 3 - selectivity up to 99%) is achieved under visible-light irradiation (>420 nm). This study provides new insight for the high-performance photo-Fenton process via a transient structure reconstitution pathway for the removal of gas phase NO x pollutants.

A piezoelectric polymer membrane based on single metal atoms was demonstrated to be effective by anchoring isolated calcium (Ca) atoms on a composite of nitrogen-doped carbon and polyvinylidene fluoride (PVDF). The addition of Ca-atom-anchored carbon nanoparticles not only promotes the formation of the β phase (from 29.8 to 56.3%), the most piezoelectrically active phase, in PVDF, but also introduces much higher porosity and hydrophilicity. Under ultrasonic excitation, the fabricated catalyst membrane demonstrates a record-high and stable dye decomposing rate of 0.11 min -1 and antibacterial efficiencies of 99.8%. Density functional theory calculations reveal that the primary contribution to catalytic activity arises from single-atom Ca doping and that a possible synergistic effect between PVDF and Ca atoms can improve the catalytic performance. It is shown that O 2 molecules can be easily hydrogenated to produce ·OH on Ca-PVDF, and the local electric field provided by the β-phase-PVDF might enhance the production of ·O 2 - . The proposed polymer membrane is expected to inspire the rational design of piezocatalysts and pave the way for the application of piezocatalysis technology for practical environmental remediation.

Amorphous noble metals with high surface areas have attracted significant interest as heterogeneous catalysts due to the numerous dangling bonds and abundant unsaturated surface atoms created by the amorphous phase. However, synthesizing amorphous noble metals with high surface areas remains a significant challenge due to strong isotropic metallic bonds. This paper describes the first example of a mesoporous amorphous noble metal alloy [iridium-tellurium (IrTe)] obtained using a micelle-directed synthesis method. The resulting mesoporous amorphous IrTe electrocatalyst exhibits excellent performance in the electrochemical N 2 reduction reaction. The ammonia yield rate is 34.6 μg mg -1 h -1 with a Faradaic efficiency of 11.2% at -0.15 V versus reversible hydrogen electrode in 0.1 M HCl solution, outperforming comparable crystalline and Ir metal counterparts. The interconnected porous scaffold and amorphous nature of the alloy create a complementary effect that simultaneously enhances N 2 absorption and suppresses the hydrogen evolution reaction. According to theoretical simulations, incorporating Te in the IrTe alloy effectively strengthens the adsorption of N 2 and lowers the Gibbs free energy for the rate-limiting step of the electrocatalytic N 2 reduction reaction. Mesoporous chemistry enables a new route to achieve high-performance amorphous metalloid alloys with properties that facilitate the selective electrocatalytic reduction of N 2 .

Oxygen reduction and evolution reactions (ORR and OER, respectively) are vital steps for metal-air batteries, which are plagued by their sluggish kinetics. It is still a challenge to develop highly effective and low-cost non-noble-metal-based electrocatalysts. Herein, a simple and reliable method was reported to synthesize a Co 2 P-assisted Co single-atom (Co-N 4 centers) electrocatalyst (Co 2 P/Co-NC) via evaporative drying and pyrolysis processes. The Co 2 P nanoparticles and Co-N 4 centers are uniformly distributed on the nitrogen-doped carbon matrix. Notably, Co 2 P/Co-NC showed excellent activities in both ORR (initial potential, 1.01 V; half-wave potential, 0.88 V) and OER (overpotential, 369 mV at 10 mA cm -2 ). The above results were comparable to those of commercial catalysts (such as Pt/C and RuO 2 ). Based on the experimental and theoretical analyses, the impressive activity can be ascribed to the tailored electronic structure of Co-N 4 centers by the adjacent Co 2 P, enabling the electron transfer from the Co atom to the neighboring C atoms, leading to a downshift of the d-band center, and improved reaction kinetics were achieved. The assembled Zn-air batteries using Co 2 P/Co-NC as the air cathode showed a peak power density of 187 mW cm -2 and long-life cycling stability for 140 h at 5 mA cm -2 . This work may pave a promising avenue to design hybrid bifunctional electrocatalysts for highly efficient ORR/OER.

With the rapid development of triboelectric nanogenerators (TENGs) for flexible wearable devices and electronic skins, challenges have gradually emerged related to the electrification surface, such as pollutant contamination and sophisticated surface adaptability. Hence, we report a simple spraying method to produce a shape-adaptive photocatalytic (SAP) triboelectric material with both self-cleaning and shape-adaptive functions. By spraying the polyvinyl alcohol solution with TiO 2 photocatalysts and pre-drying cyclic, the SAP film can be adapted to a varied and intricate substrate. The highest transferred charge density of the SAP film reaches 197.5 μC/m 2 , when it contacts with the PTFE film. At the same time, it can degrade 74.4% of simulated pollutants under sunlight illumination, and 97% of the transferred charge density can be maintained after the degradation process, indicating good self-cleaning function and stable electrical output. Moreover, the spraying method of this allows it to have shape-adaptive functions. Accordingly, the SAP film can be deposited on the rectangular pyramid and hemispherical surface for fabricating TENGs with special shapes. This low-cost and simple spraying method further promotes the commercialized application of TENGs in the field of wearable devices and skin sensors.

Learning from the important role of porphyrin-based chromophores in natural photosynthesis, a bionic photocatalytic system based on tetrakis (4-carboxyphenyl) porphyrin-coupled TiO 2 was designed for photo-induced treating low-concentration NO x indoor gas (550 parts per billion), achieving a high NO removal rate of 91% and a long stability under visible-light (λ ≥ 420 nm) irradiation. Besides the great contribution of the conventional • O 2 - reactive species, a synergic effect between a singlet oxygen ( 1 O 2 ) and mobile hydroxyl radicals ( • OH f ) was first illustrated for removing NO x indoor gas ( 1 O 2 + 2NO → 2NO 2 , NO 2 + • OH f → HNO 3 ), inhibiting the production of the byproducts of NO 2 . This work is helpful for understanding the surface mechanism of photocatalytic NO x oxidation and provides a new perspective for the development of highly efficient air purification systems.

Divergent synthesis of four contorted aromatics containing pentagons, a heptagon, and/or an azulene from the same difluorenyl pentacenediene precursor were realized in one step. The subtle differences in molecular structure were confirmed by X-ray crystallography. The mechanisms for the control of different products, which involve a ring-expansion rearrangement, Scholl reactions, and/or Mallory cyclization were proposed on the basis of control experiments and DFT calculations. Such development adds good structure versatility and materials accessibility to the study of contorted aromatics.

Harvesting distributed and low-quality mechanical energies by triboelectric nanogenerators to power electrochemical reactions is beneficial to electric energy saving and certain applications. However, the conventional self-powered electrochemical process is awkward about the reaction rate, energy conversion efficiency, high-operation frequency, and mismatched impedance. Here we demonstrate an advanced self-powered electrochemical system. In comparison with the conventional system that is inert in activity, the superior power management and electrochemical reaction regulation in tandem make the novel system outstanding for hydrogen peroxide production. In addition to the visible product, an internal current efficiency of 24.6% in the system was achieved. The developed system provides an optimization strategy toward electric energy saving for electrochemical reactions as well as enabling their applications in remote areas by converting environmental mechanical vibrational energy for ecological improvement or recyclable chemical fuel generation.

Herein, we introduce polymer nanofibers of TiO 2 @NiCo-LDH as interlayers into Li-S batteries. From 0 to 60 °C, the interlayers can deliver high sulfur utilization, an outstanding rate capability, and excellent cycling life. High-temperature excitation makes it easier for the valence band electrons of TiO 2 to transition to the conduction band. The electron-hole pairs formed on the surface combine with the ether group of 1,3-dioxolane in the electrolyte, which greatly reduces the decomposition and volatilization rates of the electrolyte, ensuring Li-S batteries with good cycle performance at high temperatures. The capacity can stabilize at 798.6 mAh g -1 after 100 cycles at 60 °C and 1C, and the battery can provide a capacity higher than 323.2 mAh g -1 at 0 °C. Simultaneously, the lithium metal symmetrical battery with a functional separator can be continuously cycled for 1800 and 750 h without a short circuit at the current densities of 0.65 and 1.63 mA cm -2 , respectively.

The effective activation and utilization of O 2 have always been the focus of scientists because of its wide applications in catalysis, organic synthesis, life and medical science. Here, a novel method for activating O 2 spontaneously via interfacial oxygen vacancies on carbon-coated TiO 2- x to generate reactive oxygen species (ROS) with versatile applications is reported. The interfacial oxygen vacancies can be stabilized by the carbon layer and hold its intrinsic properties for spontaneous oxygen activation without light irradiation, while common surface oxygen vacancies on TiO 2- x are always consumed by the capture of H 2 O to form the surface hydroxyls. Thus, O 2 absorbed at the interface of carbon and TiO 2- x can be directly activated into singlet oxygen ( 1 O 2 ) or superoxide radicals (·O 2 - ), confirmed both experimentally and theoretically. These reactive oxygen species exhibit excellent performance in oxidation reactions and inhibition of MCF-7 cancer cells, providing new insight into the effective utilization of O 2 via oxygen vacancies on metal oxides.

The photoelectrocatalytic (PEC) technique has attracted much attention to getting clear energy and environmental purification. Simultaneous reactions of solar energy generation could be used to apply for practical applications to maximize the functionality of reactor systems. Herein, we crafted a self-driving photoelectrocatalytic reactor system, comprising platinum (Pt) modified p-Si nanowires (Pt/Si-NWs) as a photocathode and TiO 2 nanotube arrays (TiO 2 -NTAs) as a photoanode for synergistic H 2 evolution and water purification, respectively. Hydrogen evolution in the cathode chamber and environmental remediation in the anode chamber were achieved with the aid of appropriate bandgap illumination and self-built bias voltage. The mismatch of Fermi levels between TiO 2 -NTAs and Si-NWs reduced the recombination rates of photoinduced electrons and holes through the formation of Z scheme and inner electric filed. The synergistic PEC reactions exhibited much higher activities than those achieved using other systems so far. This basic principal could be applied for fabricating other PEC reactors in photoelectro conversion devices and be established as design guidelines for reactors to maximize the PEC performance.

The synergistic photocatalytic Fenton reaction is a powerful advanced oxidation technique for the degradation of persistent organic pollutants. However, microwave-induced thermal effects on the formation of novel structures facilitating the photocatalytic degradation have been rarely reported. Herein, a two-step microwave thermal strategy was developed to synthesize a new hybrid catalyst comprising defective WO 3- x nanowires coupled with reduced graphene oxides (rGOs). Conventionally, microwave methods could induce superhot spots on the GO surface, resulting in the site-specific crystallization and oriented growth of WO 3 . However, in the solid phase, localized microwave thermal effects could reduce the interfacial area between WO 3 and rGO and enhance the bonding between them. As for the unique structure and surface properties, the synthesized catalyst enhanced the light absorption, promoted the interfacial charge separation, and increased the carrier density in the photocatalytic processes. In addition, surface formation of W 4+ provided a new pathway for Fe 3+ /Fe 2+ cycling which linked the photocatalytic reaction and the Fenton process. The optimized catalyst exhibited a remarkable performance in the degradation of bisphenol A with a ∼83% removal yield via a photo-Fenton route. These microwave-induced functionalities of materials for synergistic reactions could also give a new avenue to other photoelectrocatalytic fields and solar cells.

A facile in situ one-step route for the preparation of platinum nanoparticles supported on metal-organic frameworks (MOFs) without adding stabilizing agents was developed. The obtained 10% Pt@MOF-T3 material possessed a large surface area and high crystallinity. Meanwhile, uniform and well-dispersed platinum nanoparticles were formed inside the cavities of MOFs, which could be attributed to the efficient complexation and stabilization effect derived from the dipyridyl groups. The as-synthesized 10% Pt@MOF-T3 sample showed high activity and selectivity in the hydrogenation of 5-hydroxymethylfurfural (HMF). This excellent catalytic performance could be attributed to the synergistic effects of well-dispersed platinum nanoparticles and electron donation offered by MOFs. Meanwhile, the presence of bipyridine ligands in the MOF framework avoided the irreversible adsorption of the hydrocarbon compounds, leading to the enhanced catalytic efficiency. Besides, it was easily recycled and reused at least five times, showing good recyclability., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

Most photoelectrocatalytic (PEC) reactions are performed in the liquid phase for convenient electron transfer in an electrolyte solution. Herein, a novel PEC reactor involving a tandem combination of TiO 2 nanorod array/fluorine-doped tin oxide (TiO 2 -NR/FTO) working electrodes and an electrochemical auxiliary cell was constructed to drive the highly efficient PEC oxidation of indoor gas (NO x ). With the aid of a low bias voltage (0.3 V), the as-formed PEC reactor exhibited an 80% removal rate for oxidizing NO (500 ppb) under light irradiation, which is much higher than that of the traditional photocatalytic (PC) process. Upon being irradiated by light, the photogenerated electrons are quickly separated from the holes and transferred to the counter electrode (Pt) owing to the applied bias voltage, leaving photogenerated holes in the TiO 2 -NR/FTO electrode for oxidizing NO molecules. Moreover, both dry and humid NO could be effectively removed by the tandem TiO 2 -NR/FTO-based gas-phase PEC reactor, indicating that the NO molecules could also be directly oxidized by photogenerated holes in addition to hydroxyl radicals. The presence of trace amounts of water could promote the PEC oxidation of NO owing to the formation of hydroxyl radicals induced by reactions between the water and holes, which could further oxidize NO. This PEC reactor offers an energy-saving, environmentally friendly, and efficient route to treat air polluted with low concentrations of gases (NO x and SO x ).

This work reports a moderate round-the-clock route to treating organic pollutants by utilizing a La 2 NiO 4 hollow-sphere microreactor. A glycerol-assisted solvothermal route followed by an annealing process was applied for fabricating the catalyst. Both the physicochemical properties and the catalytic performance of the as-obtained microreactor for treating pollutants were discussed. The microreactor exhibited a strong ability to degrade phenol and anionic dyes in the absence of light irradiation, owing to its high surface area and positively charged surface. With the aid of visible-light irradiation, the degradation rate of the organic pollutants could be further accelerated due to the light multireflection in a hollow structure, which enhances the utilization of light. The present work indicates that the hollow-sphere La 2 NiO 4 microreactor is effectively energy saving for environmental remediation.

A unique strategy for the direct preparation of primary amine-functionalized ordered mesoporous phenolic resin (NH 2 -MPRN) was presented. The essence of our approach avoided the side reactions in the m-nitrophenol-formaldehyde resol synthesis using m-nitrophenol and formaldehyde as the monomers. Importantly, these resols can efficiently assemble with triblock copolymer F127 to form a mesostructured composite. The final prolysis treatment removed the F127 template to produce ordered mesopores, and meanwhile, the accompanying reductive gas in situ transferred the nitro groups to primary amines. Notably, the obtained NH 2 -MPRN material delivered fast toxic hexavalent chromium sorption kinetics with high uptake capacity and selectivity due to a mesoporous structure, high amine availability, and a hydrophobic surface. Interestingly, almost all of adsorbed chromium species existed as low-toxic trivalent chromium in the resin owing to the cooperative detoxification process by the neighboring primary amines and phenolic hydroxyl groups. Also, it showed the reversible detoxification for at least five times.

Photocatalytic fuel cells (PFCs) have proven to be effective for generating electricity and degrading pollutants with a goal to resolve environmental and energy problems. However, the degradation of persistent organic pollutants (POPs), such as perfluorooctanoic acid (PFOA), remains challenging. In the present work, a porous coral-like WO 3 /W (PCW) photoelectrode with a well-designed energy band structure was used for the photoelectrocatalytic degradation of POPs and the simultaneous generation of electricity. The as-constructed bionic porous coral-like nanostructure greatly improved the light-harvesting capacity of the PCW photoelectrode. A maximum photocurrent density (0.31 mA/cm 2 ) under visible light (λ > 420 nm) irradiation and a high incident photon conversion efficiency (IPCE) value (5.72% at 420 nm) were achieved. Because of the unique porous coral-like structure, the suitable energy band position, and the strong oxidation ability, this PCW photoelectrode-based PFC system exhibited a strong ability for simultaneous photoelectrocatalytic degradation of PFOA and electricity generation under visible-light irradiation, with a power output of 0.0013 mV/cm 2 using PFOA as the fuel. This work provides a promising way to construct a reliable PFC using highly toxic POPs to generate electricity.

To circumvent the imbalances of electrochemical kinetics and capacity between Li + storage anodes and capacitive cathodes for lithium-ion capacitors (LICs), we herein demonstrate an efficient solution by boosting the capacitive charge-storage contributions of carbon electrodes to construct a high-performance LIC. Such a strategy is achieved by the in situ and high-level doping of nitrogen atoms into carbon nanospheres (ANCS), which increases the carbon defects and active sites, inducing more rapidly capacitive charge-storage contributions for both Li + storage anodes and PF 6 - storage cathodes. High-level nitrogen-doping-induced capacitive enhancement is successfully evidenced by the construction of a symmetric supercapacitor using commercial organic electrolytes. Coupling a pre-lithiated ANCS anode with a fresh ANCS cathode enables a full-carbon LIC with a high operating voltage of 4.5 V and high energy and power densities thereof. The assembled LIC device delivers high energy densities of 206.7 and 115.4 Wh kg -1 at power densities of 0.225 and 22.5 kW kg -1 , respectively, as well as an unprecedented high-power cycling stability with only 0.0013% capacitance decay per cycle within 10 000 cycles at a high power output of 9 kW kg -1 .

Heterogeneous organometallic catalysts with well-defined active sites and hierarchical pores hold tremendous promise for efficient and eco-friendly chemical processes. However, the simple and scalable preparation of these materials remains difficult to date, which has hampered a more broad application scope. Herein, we reported a low-cost, rapid, and scalable aerosol-assisted assembly approach for the synthesis of a well-defined PdDPP (PdCl 2 (PPh 2 (CH 2 ) 2 ))_ complex-containing benzene-bridged organosilica-based catalyst with a hierarchical bimodal micro-macroporous structure. This novel material was realized by using Pd(II) organometallic silane (Pd[PPh 2 (CH 2 ) 2 Si(OEt) 3 ] 2 Cl 2 ) as the active species, organosilane 1,4-bis(triethoxysilyl)benzene (Ph[Si(OEt) 3 ] 2 ) as the silicate scaffold and the surfactant cetyltrimethylammonium bromide and the inorganic salt NaCl as the dual templates on a home-built aerosol spraying-instrument. Multiple techniques including X-ray photoelectron spectroscopy and solid-state NMR spectra revealed that the organopalladium complex with a well-defined molecular configuration of major trans model and minor cis model existed in the phenyl-functionalized silica material. As expected, it efficiently promoted a variety of important carbon-carbon cross-coupling transformations including Tsuji-Trost, Sonogashira, and Suzuki reactions in pure water without the assistance of any additives. In comparison with the homogeneous catalyst PdCl 2 (PPh 2 CH 3 ) 2 , it even exhibited enhanced activity and selectivity in some cases owing to the unique confinement effect and the shape selectivity generated from the hierarchical porous structure. Meanwhile, it was easily recycled and reused eight times without the loss of its activity.

Recently, atmospheric pollution caused by particulate matter or volatile organic compounds (VOCs) has become a serious issue to threaten human health. Consequently, it is highly desirable to develop an efficient purifying technique with simple structure and low cost. In this study, by combining a triboelectric nanogenerator (TENG) and a photocatalysis technique, we demonstrated a concept of a self-powered filtering method for removing pollutants from indoor atmosphere. The photocatalyst P25 or Pt/P25 was embedded on the surface of polymer-coated stainless steel wires, and such steel wires were woven into a filtering network. A strong electric field can be induced on this filtering network by TENG, while both electrostatic adsorption effect and TENG-enhanced photocatalytic effect can be achieved. Rhodamine B (RhB) steam was selected as the pollutant for demonstration. The absorbed RhB on the filter network with TENG in 1 min was almost the same amount of absorption achieved in 15 min without using TENG. Meanwhile, the degradation of RhB was increased over 50% under the drive of TENG. Furthermore, such a device was applied for the degradation of formaldehyde, where degradation efficiency was doubled under the drive of TENG. This work extended the application for the TENG in self-powered electrochemistry, design and concept of which can be possibly applied in the field of haze governance, indoor air cleaning, and photocatalytic pollution removal for environmental protection.

Pt-doped mesoporous Ti 3+ self-doped TiO 2 (Pt-Ti 3+ /TiO 2 ) is in situ synthesized via an ionothermal route, by treating metallic Ti in an ionic liquid containing LiOAc, HOAc, and a H 2 PtCl 6 aqueous solution under mild ionothermal conditions. Such Ti 3+ -enriched environment, as well as oxygen vacancies, is proven to be effective for allowing the in situ reduction of Pt 4+ ions uniformly located in the framework of the TiO 2 bulk. The photocatalytic H 2 evolution of Pt-Ti 3+ /TiO 2 is significantly higher than that of the photoreduced Pt loaded on the original TiO 2 and commercial P25. Such greatly enhanced activity is due to the various valence states of Pt (Pt n+ , n = 0, 2, or 3), forming Pt-O bonds embedded in the framework of TiO 2 and ultrafine Pt metal nanoparticles on the surface of TiO 2 . Such Pt n+ -O bonds could act as the bridges for facilitating the photogenerated electron transfer from the bulk to the surface of TiO 2 with a higher electron carrier density (3.11 × 10 20 cm -3 ), about 2.5 times that (1.25 × 10 20 cm -3 ) of the photoreduced Pt-Ti 3+ /TiO 2 sample. Thus, more photogenerated electrons could reach the Pt metal for reducing protons to H 2 .

Here, we compare analogous cyclic and acyclic π-conjugated molecules as n-type electronic materials and find that the cyclic molecules have numerous benefits in organic photovoltaics. This is the first report of such a direct comparison. We designed two conjugated cycles for this study. Each comprises four subunits: one combines four electron-accepting, redox-active, diphenyl-perylenediimide subunits, and the other alternates two electron-donating bithiophene units with two diphenyl-perylenediimide units. We compare the macrocycles to acyclic versions of these molecules and find that, relative to the acyclic analogs, the conjugated macrocycles have bathochromically shifted UV-vis absorbances and are more easily reduced. In blended films, macrocycle-based devices show higher electron mobility and good morphology. All of these factors contribute to the more than doubling of the power conversion efficiency observed in organic photovoltaic devices with these macrocycles as the n-type, electron transporting material. This study highlights the importance of geometric design in creating new molecular semiconductors. The ease with which we can design and tune the electronic properties of these cyclic structures charts a clear path to creating a new family of cyclic, conjugated molecules as electron transporting materials in optoelectronic and electronic devices.