Naphthalene diimide (NDI)-based conjugated polymers have been widely used as the nonfullerene electron acceptor for all-polymer solar cells (all-PSCs), but their low absorption coefficient in the ...near-infrared (NIR) region severely limits the light harvesting ability in solar cells and hence lowers their photovoltaic performance. In this work, two narrow band gap donor–acceptor conjugated polymers based on boron dipyrromethene (BODIPY) as the electron-deficient unit were developed as the electron donor to combine with a NDI-polymer acceptor in order to significantly improve the photoresponse in the NIR region. More importantly, we found that methyl substitution on the BODIPY segment played an important role in charge transport in these polymers. When methyl units were attached to the α-position of BODIPY, the polymer PMBBDT exhibited high-lying energy levels, improved crystallinity, and dramatically high hole mobility compared to the polymer PBBDT without methyl substitution. Consequently, the power conversion efficiencies (PCEs) could be enhanced from 0.32% for PBBDT- to 5.8% for PMBBDT-based all-PSCs, and the photoresponse covered from 300 to 900 nm. Our results demonstrate that methyl-substituted BODIPY-based conjugated polymers are promising candidates to solve the NIR absorption issue in NDI polymers and, therefore, can be potentially used to further boost the PCEs of all-PSCs similar with organic solar cells based on NIR-fused ring electron acceptors.
The position of deposits and ore bodies for the underground mining in the underground mine Jama Bor, in relation to the terrain surface, old works of the Jama and Open Pit in Bor, and in relation to ...the mining infrastructure limits the selection of excavation methods with the applied technologies up to now. This paper presents the block method of excavation with backfilling the excavated space with the paste backfill of the Bor River deposit.
Two‐dimensional materials have led to a leap forward in materials science research, especially in the fields of energy conversion and storage. Borophene and its spherical counterpart boron fullerene ...represent emerging materials that have attracted much attention in the whole area of advanced energy materials and technologies. Owing to their prominent features, such as electronic environment and geometry, borophene and boron fullerene have been used in versatile applications, such as supercapacitors, superconductors, anode materials for photochemical water splitting, and biosensors. Herein, one of the most promising applications/areas of hydrogen storage is discussed. Boron fullerenes have been considered and discussed for hydrogen‐storage applications, and recently borophene was also included in the list of materials with promising hydrogen‐storage properties. Studies focus mainly on doped borophene systems over pristine borophene due to enhanced features available upon decoration with metal atoms. This Review introduces very recent progress and novel paradigms with respect to both borophene derivatives and boron fullerene based systems reported for hydrogen storage, with a focus on the synthesis, physiochemical properties, hydrogen‐storage mechanism, and practical applications.
Future fuel sources: Energy‐storage systems are a hot topic of research in materials science. Borophene and boron fullerenes are 2D materials suitable for application as hydrogen‐storage systems. These materials allow versatile applications, such as supercapacitors, superconductors, anode materials for photochemical water splitting, and biosensors, owing to their prominent features (electronic environment, geometry).
We report on the oxidative dehydrogenation (ODH) activity of silica-supported boron oxide prepared via incipient wetness impregnation. Characterization of pristine and spent catalysts with infrared, ...Raman, and solid-state NMR spectroscopy reveals the presence of both isolated and aggregated oxidized boron sites. The results of these investigations, in combination with our earlier work on bulk boron-containing ODH catalysts (e.g., h-BN, metal borides, and elemental boron), give direct evidence that oxidized boron species formed in situ on the surface of these materials are responsible for the exceptional catalytic behavior. We anticipate that investigation of supported boron materials can provide insight into the structural characteristics required for selective boron-containing ODH catalysts.
A series of novel BN tetraphene derivatives have been prepared successfully for the first time via a post‐functionalization strategy. The optical and electronic properties of these derivatives could ...be tuned systematically by the incorporation of different substituents on the main skeleton. The functionalized BN‐containing luminogens have been explored for the detection of latent fingerprints (LFPs) on different substrates, including glass, aluminum foil, plastic, and ironware. This strategy provides great versatility in LFP imaging and good potential in elucidating the chemical information within LFPs, making the strategy valuable in forensic investigations.
New tool for forensic science: Polycyclic aromatic hydrocarbons modified with a BN unit show outstanding luminescence properties. In powdered form, these compounds can be used for fast and high‐resolution imaging of latent fingerprints under simple operating conditions. Even the second level of unique details of the fingerprint can be visualized.
n‐Type Azaacenes Containing B←N Units Min, Yang; Dou, Chuandong; Tian, Hongkun ...
Angewandte Chemie International Edition,
February 12, 2018, Letnik:
57, Številka:
7
Journal Article
Recenzirano
We disclose a novel strategy to design n‐type acenes through the introduction of boron–nitrogen coordination bonds (B←N). We synthesized two azaacenes composed of two B←N units and six/eight linearly ...annelated rings. The B←N unit significantly perturbed the electronic structures of the azaacenes: Unique LUMOs delocalized over the entire acene skeletons and decreased aromaticity of the B←N‐adjacent rings. Most importantly, these B←N‐containing azaacenes exhibited low‐lying LUMO energy levels and high electron affinities, thus leading to n‐type character. The solution‐processed organic field‐effect transistor based on one such azaacene exhibited unipolar n‐type characteristics with an electron mobility of 0.21 cm2 V−1 s−1.
BN there makes all the difference: The introduction of B←N units into azaacenes causes significant perturbations of their electronic structures and properties: Unique LUMOs delocalized over the acene skeletons (see picture) decrease aromaticity of the B←N‐adjacent rings and n‐type character. A solution‐processed organic field‐effect transistor based on one of the azaacenes exhibited unipolar n‐type characteristics and high electron mobility.
This review examines the current status (from 2016 to December 2018) of the electroanalytical application of boron-doped diamond (BDD), in view of its advantages and challenges for electroanalytical ...applications. The effect of the boron-doping level, sp
3
/sp
2
ratio, and BDD surface termination on the electrochemical properties of BDD electrodes is discussed. The most interesting and significant developments concerning the electrochemical oxidation and reduction of chemical substances onto BDD in single and multi-analyte modes, the beneficial role of surfactants in BDD electrode-based electroanalysis, surface modifications, modification of electrode surfaces with metal nanoparticles, porous BDD surfaces, and the specificity of BDDEs in the microfluidic context, are considered. Basic information on the electroanalysis of organic substances in single- and multi-analyte detection modes is given in the tables. Other non-common electroanalytical applications of BDD, such as BDD as an electrode material for electrogenerated electrochemiluminescence, and BDD for
in vivo
on-line determination of analytes, detecting bio-potential changes in plants, and pH and gas sensing, are presented.
This review examines the current status (from 2016 to December 2018) of the electroanalytical application of boron-doped diamond (BDD), in view of its advantages and challenges for electroanalytical applications.
Electropositive boron‐based substituent (phosphonium bora‐ylide) with an exceptionally strong π‐ and σ‐electron donating character dramatically increases the stability of a new type of N‐heterocyclic ...silylene 2 featuring amino‐ and bora‐ylide‐substituents. Moreover, the related silylium ion 4 and transition‐metal–silylene complexes, with trigonal‐planar geometries around the silicon center, are also well stabilized. Therefore, the N,B‐heterocyclic silylene 2 can be used as a strongly electron‐donating innocent ligand in coordination chemistry similarly to N‐heterocyclic carbenes.
Electron‐donating ligand: An electropositive boron‐based substituent (phosphonium bora‐ylide) with an exceptionally strong π‐ and σ‐electron donating character increases the stability of a new type of N‐heterocyclic silylene featuring amino and bora‐ylide substituents. It also efficiently stabilizes the related silylium ion and transition‐metal–silylene complexes even with a trigonal‐planar geometry around the silicon center.
Boron and nitrogen co-doped carbon (BCN) seems to exhibit excellent electrochemical properties very suitable as electrode material for supercapacitor applications. On the other hand, MoS2 possessing ...sheet-like structure proves to be favorable for electrolytic ion intercalation. Here in composites resulting from hydrothermally integrated MoS2 flakes with the BCN have been studied to determine its potency as electrode material for supercapacitor application. Owed to the high packing density of layered MoS2 flakes the as-prepared BCN/MoS2 composite exhibits high volumetric capacitance corresponding to a value of 798 F cm−3 together with the enhanced gravimetric capacitance of 283 F g−1 at the current density of 1 A g−1. Electrochemical studies reveal improved coulombic efficiency, energy, and power densities for the as-prepared BCN/MoS2 composite owed to the established synergy and the presence of interfaces involving two different materials. These results clearly show the usefulness of integration BCN and MoS2 flakes resulting in BCN/MoS2 hybrid as an apt electrode material for supercapacitor application.
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•Composite with integrated BCN and MoS2 shows augmented capacitive properties.•BCN/MoS2 composite shows excellent volumetric capacitance due to high density.•Created interlayer interfaces enhance coulombic efficiency and cyclic stability.•The energy and power density for the BCN/MoS2 composite also undergo a boost.
Tungsten tetraboride is an inexpensive, superhard material easily prepared at ambient pressure. Unfortunately, there are relatively few compounds in existence that crystallize in the same structure ...as tungsten tetraboride. Furthermore, the lack of data in the tetraboride phase space limits the discovery of any new superhard compounds that also possess high incompressibility and a three-dimensional boron network that withstands shear. Thus, the focus of the work here is to chemically probe the range of thermodynamically stable tetraboride compounds with respect to both the transition metal and the boron content. Tungsten tetraboride alloys with a variable concentration of boron were prepared by arc-melting and investigated for their mechanical properties and thermal stability. The purity and phase composition were confirmed by energy dispersive X-ray spectroscopy and powder X-ray diffraction. For variable boron WB x , it was found that samples prepared with a metal to boron ratio of 1:11.6 to 1:9 have similar hardness values (∼40 GPa at 0.49 N loading) as well as having a similar thermal oxidation temperature of ∼455 °C. A nearly single phase compound was successfully stabilized with tantalum and prepared with a nearly stoichiometric amount of boron (4.5) as W0.668Ta0.332B4.5. Therefore, the cost of production of WB4 can be decreased while maintaining its remarkable properties. Insights from this work will help design future compounds stable in the adaptable tungsten tetraboride structure.
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