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(TaF6)2NiN6 is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is zero-dimensional and consists of four nickel ammine bromide molecules and eight TaF6 clusters. In each TaF6 cluster, Ta5+ is bonded in an octahedral geometry to six equivalent F1- atoms. All Ta–F bond lengths are 1.92 Å. F1- is bonded in a single-bond geometry to one Ta5+ atom.
HgBr2C4NBr crystallizes in the monoclinic P2_1 space group. The structure is one-dimensional and consists of four mercuric bromide molecules; two C4NBr clusters; and two C4NBr ribbons oriented in the (0, 0, 1) direction. In each C4NBr cluster, there are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one C1+ and one Br1- atom. The C–C bond length is 1.26 Å. The C–Br bond length is 1.79 Å. In the second C1+ site, C1+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.21 Å. In the third C1+ site, C1+ is bonded in a linear geometry to two C1+ atoms. The C–C bond length is 1.30 Å. In the fourth C1+ site, C1+ is bonded in a single-bond geometry to one C1+ and one N3- atom. The C–N bond length is 1.28 Å. N3- is bonded in a linear geometry to two C1+ atoms. Br1- is bonded in a single-bond geometry to one C1+ atom. In each C4NBr ribbon, there are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one C1+ and one N3- atom. The C–C bond length is 1.25 Å. The C–N bond length is 1.25 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one C1+ and one Br1- atom. The C–Br bond length is 1.81 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one C1+ and one N3- atom. The C–C bond length is 1.30 Å. The C–N bond length is 1.24 Å. In the fourth C1+ site, C1+ is bonded in a linear geometry to one C1+ and one Br1- atom. The C–Br bond length is 2.60 Å. N3- is bonded in a linear geometry to two C1+ atoms. Br1- is bonded in a linear geometry to two C1+ atoms.
HgBr2C2NBr crystallizes in the monoclinic P2/c space group. The structure is zero-dimensional and consists of two mercuric bromide molecules, eight C2NBr clusters, and two HgBr2 clusters. In each C2NBr cluster, there are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a water-like geometry to one N3- and one Br1- atom. The C–N bond length is 1.33 Å. The C–Br bond length is 1.90 Å. In the second C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.21 Å. N3- is bonded in a linear geometry to two C2+ atoms. Br1- is bonded in a single-bond geometry to one C2+ atom. In each HgBr2 cluster, there are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 2-coordinate geometry to three Br1- atoms. There are a spread of Hg–Br bond distances ranging from 2.45–3.35 Å. In the second Hg2+ site, Hg2+ is bonded in a linear geometry to two equivalent Br1- atoms. Both Hg–Br bond lengths are 2.45 Å. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted bent 120 degrees geometry to two Hg2+ atoms. In the second Br1- site, Br1- is bonded in a single-bond geometry to one Hg2+ atom. In the third Br1- site, Br1- is bonded in a single-bond geometry to one Hg2+ atom.
NiBr2(C)3BrCN crystallizes in the monoclinic P2_1 space group. The structure is one-dimensional and consists of two cyanogen bromide molecules; two propane molecules; and one NiBr2 ribbon oriented in the (0, 1, 0) direction. In the NiBr2 ribbon, Ni2+ is bonded in a square co-planar geometry to four Br1- atoms. All Ni–Br bond lengths are 2.33 Å. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in an L-shaped geometry to two equivalent Ni2+ atoms. In the second Br1- site, Br1- is bonded in an L-shaped geometry to two equivalent Ni2+ atoms.
CrN5ClPtBr4 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four platinum(iv) bromide molecules and four CrN5Cl clusters. In each CrN5Cl cluster, Cr6+ is bonded in a 4-coordinate geometry to three N+1.40- and one Cl1- atom. There is two shorter (1.62 Å) and one longer (2.19 Å) Cr–N bond length. The Cr–Cl bond length is 2.15 Å. There are three inequivalent N+1.40- sites. In the first N+1.40- site, N+1.40- is bonded in a single-bond geometry to one Cr6+ atom. In the second N+1.40- site, N+1.40- is bonded in a T-shaped geometry to one Cr6+ and two equivalent N+1.40- atoms. Both N–N bond lengths are 1.21 Å. In the third N+1.40- site, N+1.40- is bonded in a 1-coordinate geometry to one N+1.40- atom. Cl1- is bonded in a single-bond geometry to one Cr6+ atom.
CNCOBr crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two formyl bromide molecules and two hydrogen cyanide molecules.
Remediation of Tc remains an unresolved problem at SRS and other DOE sites. The objective of this project was to develop novel metal organic framework (MOF) glasses for radioactive contaminant sequestration and stabilization from aqueous media. During FY20, we synthesized, characterized and evaluated additional cetyltrimethylcimmonium bromide (CTAB)-functionalized and F - , Cl - , I - , CF 3 SO 3 - exchanged MIL-101-Cr samples. MIL-10l-Cr-NO 3 -CTAB was demonstrated to have high ReO 4 - removed capacity (139 mg/g sorbent) from artificial groundwater (AGW). Re chemical specicition and binding mechanism on MIL-101-CTAB were also studied by synchrotron X-ray absorption spectroscopy. ReO 4 - was demonstrated as being in the pore structure with slightly larger Re-O bond distances than those in NciReO 4 and binding with the positively charged sites of CTAB. In addition, a new Ni-TIPA MOF was demonstrated to be very stable, selective and effective for TcO 4 - removed from the SRS tank waste stream (~90% removed). The Ni-TIPA MOF sample containing ReO 4 - was prepared and shipped/planned for vitrification studies by a high-pressure technique. This research may provide a highly applicable platform for solving critical DOE and industrial problems related to nuclear environmental stewardship and nuclear power production.
This project seeks to develop low-cost, high-resolution gamma scintillators based on new fracture-resistant alloys of cerium bromide. These alloys will eliminate limitations imposed by self-activity and fracture of currently available lanthanum-based scintillators.
Project Outline: • Experimental validation of machine learning based prediction models; • Evaluating double perovskite halides (chlorides, some bromides) – A 2 bb'X 6 :Ce; A = Br + , Cs + ; B = Na + , K + ; B' = RE 3+ ; X = Cl - , Br - ; • Performing single crystal growth and characterization (physical, optical, scintillation properties).
Since installing solar panels costs more than the panels themselves, it is critically important to improve the efficiency of the panels so that fewer panels need to be installed. More than 90% of all panels being manufactured are made with silicon solar cells. The most promising approach to reach 27% is to upgrade the panels by adding a second set of cells with a larger band gap that can harvest the higher energy photons in the visible spectrum and generate a higher voltage than silicon is capable of generating. Perovskite semiconductors are very promising for low-cost tandems because they have high band gaps, can be rapidly printed from solutions and have been used to make 25% efficient cells by themselves. If we show that it is possible to make stable tandems with 30% efficiency using materials that could be deposited at low cost and that the energy yield will not be compromised, then private companies would be able to raise the capital needed to manufacture this technology. The main metrics for this project are the power conversion efficiency of a lab-scale perovskite/silicon tandem and the ability to maintain a high power conversion efficiency in perovskite solar cells after accelerated operational stability testing under maximum power point at elevated temperature and 1 sun illumination. In short, this project demonstrates improvements to the perovskite absorber layer, contacts for the perovskite solar cell, and transparent oxide layers for window electrodes to achieve tandem efficiencies of 25% after one year and 27% after two years. By the end of the project, we identify strategies to further improve light management in the tandem devices and outline a pathway to reach 30%.In parallel, stability testing is conducted to evaluate said absorber and contact layers in the perovskite top cell, demonstrating 1000 hours of operation with less than 10% degradation at 1 sun. Our work on this project has made a leading impact on the development of perovskite/silicon tandems. The triple halide perovskite that we developed using iodide, bromide, and chloride and published in Science in March 2020 has received significant interest from other experts in the field at conferences. We took a silicon bottom cell with 21% efficiency, a technology that is responsible for a $30 billion market, and improved it by 30% relative. In addition, we have demonstrated impressive stability of our perovskite semitransparent top cells used in the tandems, showing for the first time packaged devices that pass a variety of IEC stability tests including damp heat, temperature cycling, and UV exposure tests.
The primary objective of this project is to characterize coal contaminants in coal-fired power plant wastewater as a function of coal type, unit configurations, and unit operation profile with uncertainty analysis. This project was in response to the U.S. Department of Energy (DOE) Solicitation DE-FOA-0001842. The project duration was between September 01, 2018, and December 31, 2021 (no-cost extension filed, due to the Covid-19 pandemic restrictions, and approved). Field and lab test program was conducted with the main goal to characterize coal contaminants in coal-fired power plant wastewater as a function of coal type, unit configurations, and unit operation profile with uncertainty analysis. In this project, the team of Lehigh University (prime recipient) and Western Kentucky University identified two suitable Thermoelectric Power Plants (TTPs) firing bituminous and sub-bituminous coals respectively, designed test plans, and performed sample collection. Sampling included coal from each TTPs power generation units, Wet Flue Gas Desulfurization (WFGD) slurry material and waste-water samples taken from the outlet of the water treatment tank prior to discharge and other pertinent locations. Coal samples are dried, crushed, and pulverized according to the American Society for Testing and Materials (ASTM) methods. The prepared coal samples are analyzed for normal proximate and ultimate analysis tests in addition to the toxic metals and anions according to ASTM methods. The FGD slurry materials are analyzed for toxic metals and anions according to Electric Power Research Institute (EPRI) or Environmental Protection Agency (EPA) methods, as appropriate. The wastewater samples from the water treatment tank outlet are analyzed for toxic metals and anions according to EPA methods. The effluent species analyzed include mercury, arsenic, selenium, nitrate/nitrite, bromide, and chlorine. This project provided results of effluent conditions as a function of coal type, unit configuration, and unit operation profile, and identified the levels of uncertainty in the effluent results.
This report represents the 1st shot (in a series of 8) conducted on September 15, 2022. One 10 lb C4 charge (along with ~200g of Potassium Bromide (KBr)) was detonated inside 9920 North Pad Boom Box. Noise sampling was performed at several points on Site 9920 to characterize the noise mitigation provided by the block structure. This data will help inform safe locations for Members of the Workforce (MOWs) to be located during future testing with similar net explosive weights. During the test, all MOW/site visitors were bunkered inside Building 9926/Mobile Firing Control Point (MFCP) to prevent personnel exposure to any hazards associated with the testing
Nuclear energy is a process which achieves zero-carbon energy and heat generation that can provide a consistent electricity load to supply the grid when renewables are not available. However, on a cost per kilowatt-hour comparison, nuclear energy is more expensive than many of the renewable energy generation technologies such as wind and solar. In order to increase the economic viability of next generation nuclear reactors for energy production, generation of a secondary product such as a chemical feedstock would increase the economic viability of nuclear energy, particularly for new installations of next-generation nuclear reactors for power production. Currently, commercial nuclear reactors are primarily used for their heat to generate steam for electricity production. There is a large amount of unused energy in the form of photon and neutron radiation that could be exploited to drive chemical processes to produce feedstock materials as a secondary product of a nuclear plant. Chemical processing with radiation is not a new concept. In fact, gamma radiation is an excellent source of high energy photons to drive photochemical reactions. Dow chemical produced commercial quantities of ethyl bromide using gamma irradiation from a 60 Co source in the 1960s and 1970s because it was the most cost-effective means of production to meet the demand.5, 6 Due to the potential economic advantages, there is a new emphasis on studying feedstock production which can be enhanced by excess gamma and neutron radiation, particularly if the reaction could be monitored in real-time which is advantageous for process optimization. A model system of lignocellulose degradation under γ- radiation was chosen for this study while following the degradation products with Raman spectroscopy in real-time.
Fixed-energy Response-function Analysis with Multiple efficiency (FRAM) is a software code designed primarily for plutonium and uranium isotopic analysis. It is widely used in both the domestic and international safeguards community. FRAM can quickly and accurately determine the isotopic compositions of plutonium, uranium, and mixed oxides (MOX) when measuring with a high-purity germanium (HPGe), cadmium zinc telluride (CZT), or lanthanum bromide (LaBr3) detector. The capabilities of FRAM have been enhanced to analyze the data of the pixelated CZT detector (made by H3D) and to measure the mass of plutonium, uranium, and MOX. Both the isotopic composition and mass of the item can be quickly determined with one measurement using a gamma detector with FRAM v.7.1.
Fixed-energy Response-function Analysis with Multiple efficiency (FRAM) is a software code designed primarily for plutonium and uranium isotopic analysis. It is widely used in both the domestic and international safeguards community. FRAM can quickly and accurately determine the isotopic compositions of plutonium, uranium, and mixed oxides (MOX) when measuring with a high-purity germanium (HPGe), cadmium zinc telluride (CZT), or lanthanum bromide (LaBr 3 ) detector. The capabilities of FRAM have been enhanced to analyze the data of the pixelated CZT detector (made by H3D) and to measure the mass of plutonium, uranium, and MOX. Both the isotopic composition and mass of the item can be quickly determined with one measurement using a gamma detector with FRAM v.7.1.
Covalent organic framework (COF)-supported palladium catalysts have garnered enormous attention for cross-coupling reactions. However, the limited linkage types in COF hosts and their suboptimal catalytic performance have hindered their widespread implementation. Herein, we present the first study immobilizing palladium acetate onto a dioxin-linked COF (Pd/COF-318) through a facile solution impregnation approach. By virtue of its permanent porosity, accessible Pd sites arranged in periodic skeletons, and framework robustness, the resultant Pd/COF-318 exhibits exceptionally high activity and broad substrate scope for the Suzuki–Miyaura coupling reaction between aryl bromides and arylboronic acids at room temperature within an hour, rendering it among the most effective Pd/COF catalysts for Suzuki–Miyaura coupling reactions to date. Moreover, Pd/COF-318 demonstrates excellent recyclability, retaining high activity over five cycles without significant deactivation. The leaching test confirms the heterogeneity of the catalyst. This work uncovers the vast potential of dioxin-linked COFs as catalyst supports for highly active, selective, and durable organometallic catalysis.
This paper studies the mechanism of electrochemically induced carbon–bromine dissociation in 1-Br-2-methylnaphalene in the reduction regime. In particular, the bond dissociation of the relevant radical anion is disassembled at a molecular level, exploiting quantum mechanical calculations including steady-state, equilibrium and dissociation dynamics via dynamic reaction coordinate (DRC) calculations. DRC is a molecular-dynamic-based calculation relying on an ab initio potential surface. This is to achieve a detailed picture of the dissociation process in an elementary molecular detail. From a thermodynamic point of view, all the reaction paths examined are energetically feasible. The obtained results suggest that the carbon halogen bond dissociates following the first electron uptake follow a stepwise mechanism. Indeed, the formation of the bromide anion and an organic radical occurs. The latter reacts to form a binaphthalene intrinsically chiral dimer. This paper is respectfully dedicated to Professors Anny Jutand and Christian Amatore for their outstanding contribution in the field of electrochemical catalysis and electrosynthesis.
In the present work, we report a simple synthesis method for preparation of copolymers and nanocomposites from limonene and styrene using clay as a catalyst. The copolymerization reaction is carried out by using a proton exchanged clay as a catalyst called Mag-H+. The effect of temperature, reaction time and amount of catalyst were studied, and the obtained copolymer structure (lim-co-sty) is characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (1H-NMR) and differential scanning calorimetry (DSC). The molecular weight of the obtained copolymer is determined by gel permeation chromatography (GPC) and is about 4500 g·mol−1. The (lim-co-sty/Mag 1%, 3%, 7% and 10% by weight of clay) nanocomposites were prepared through polymer/clay mixture in solution method using ultrasonic irradiation, in the presence of Mag-CTA+ as green nano-reinforcing filler. The Mag-CTA+ is organophilic silicate clay prepared through a direct exchange process, using cetyltrimethylammonuim bromide (CTAB). The prepared lim-co-sty/Mag nanocomposites have been extensively characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). TEM analysis confirms the results obtained by XRD and clearly show that the obtained nanocomposites are partially exfoliated for the lower amount of clay (1% and 3% wt) and intercalated for higher amounts of clay (7% and 10% wt). Moreover, thermogravimetric analysis (TGA) indicated an enhancement of thermal stability of nanocomposites compared with the pure copolymer.