Electronic Modification Research Articles

The search for optimum host-guest interactions: Atomic hydrogen storage properties of the novel ternary ordered intermetallic compound Cu3ZnSb: A DFT study

Ternary Cu3ZnSb adopts the tetrahedral space group P4/nmm (129), with 10 atoms in the unit cell, distributed over four crystallographic positions in a perfectly ordered manner. It possesses two perfect tetrahedral interstitial positions, namely Cu3Sb and Cu2Zn2. The possible hydrogen storage properties in these two possible sites are explored by the aid of first-principles density functional theory calculations. The Cu-richer Cu3Sb site is energetically more favourable position for hydrogen atom, over the other one. The maximum possible H-uptake capacity would be within the range of ∼4 H per formula unit. The electronic structure modification, host-guest interactions, and electronic redistribution after hydrogen incorporation are explored from fundamental perspectives analyzing the density of states, crystal orbital Hamilton population, crystal orbital bond index, and Mulliken population calculations.

Electrocatalysis induced reconstruction of RuNiPO for highly efficient hydrogen evolution reaction

Reconstruction during the catalytic process has been considered to play a key role for the performance. Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction (HER), which can benefit from a long-term reconstruction during HER for 10 h to continuously increase the performance. The final catalyst (e-RuNiPO) shows a huge morphology change from bulk sphere to highly exposed layered structure in the electrocatalysis process, and exhibits an interesting electronic structure modification with the electron transfer from Ru to Ni for better interfacial interaction and quick charge transfer. Due to the favorable morphology with more exposed active sites and the optimized electronic structure, the final catalyst can achieve an outstanding performance with only an overpotential of 15 mV at 10 mA cm−2 (with a good stability more than 100 h), even outperforming the performance of benchmark 20 wt% Pt/C catalyst (18 mV at 10 mA cm−2) by using a much lower Ru content.

Electronic and Steric Modification of Ni Nanoparticle Surface via N-Doped Carbon Layers Enables Highly Selective Semihydrogenation of Alkynes

Electronic and Steric Modification of Ni Nanoparticle Surface via N-Doped Carbon Layers Enables Highly Selective Semihydrogenation of Alkynes

Correction to “Electronic and Surface Modifications of Ni–Co–Fe Oxides: A Catalyst with Maximum Exposure of Fe Active Sites for Water Electrolysis”

Correction to “Electronic and Surface Modifications of Ni–Co–Fe Oxides: A Catalyst with Maximum Exposure of Fe Active Sites for Water Electrolysis”

Rasburicase dose optimization for tumor lysis syndrome management in a network of community oncology practices.

Single, fixed-dose rasburicase administration has been evaluated as an effective strategy in the management of hyperuricemia in the hospital setting, but this has not yet been described within ambulatory community oncology practices. The objective of this study is to evaluate and optimize the dosing strategy for rasburicase in the management of tumor lysis syndrome (TLS)-associated hyperuricemia in The US Oncology Network (The Network). A network-wide guideline was revised to standardize rasburicase dosing from a previous recommended fixed doses of 4.5 or 7.5 mg to either 3 or 6 mg for outpatient rasburicase use in management and prevention of TLS. The primary outcome evaluated mean dose of rasburicase among all patients before and after guideline revision. A retrospective chart review evaluated secondary endpoints. The primary analysis included 291 patients (128 pre-revised and 163 post-revised guideline implementation). The primary outcome, mean rasburicase dose, was reduced in the post-revision compared to the pre-revision population (mean 6.2 mg pre vs. 4.5 mg post, p < 0.00001) resulting in a reduced cost per rasburicase dose of $974. Fifty patients were included for the secondary analysis. Guideline concordance was identified in 12 (48%) and 16 patients (64%), and uric acid <8 mg/dL post-rasburicase administration occurred in 14 (56%) and 16 patients (64%) before and after guideline revision, respectively. Guideline revision and electronic health record modification resulted in a 27% reduction in the mean rasburicase dose and a 50% reduction in repeat rasburicase dosing without a negative impact on clinical efficacy.

Photoinduced Aryl Transfer from Imidazolyl-Quinoline π-Conjugated Systems.

Aryl transfer between heteroatoms was photochemically available through radical initiation followed by a bimolecular reaction. However, such an excited-state reaction has rarely been reported through a photoinduced intramolecular pathway in the π-conjugated systems. Herein, we found, for the first time, a clean photoinduced intramolecular aryl shift for imidazolyl-quinoline derivatives 2NQ (imidazophenanthrene) and 4NQX (imidazophenanthroline), of which the photoproducts are thermally reversible. Upon light irradiation of the studied compounds in solution, an appreciable blue fluorescence along with a gradual change in color appearance was observed, the photoluminescence and photoconversion quantum yields of which were shown to be competitive in the same excited state. We were able to harness the photoconversion quantum yields of the NQ compounds with facile electronic modifications. These, in combination with time-resolved studies on the NQ compounds, gave an oxygen-insensitive aryl transfer rate within 1-100 ns. The anomalously slow intramolecular reaction rates were further proven to be associated with the ∼5.0 kcal/mol transition free energy. The photoproducts NQ_rs were isolated, identified by X-ray analyses, and also shown to demonstrate anti-Vavilov reverse reactions back to the NQ compounds in the higher-lying excited state. The discovery of photoinduced intramolecular aryl transfer paves a new pathway in the synthetic field, which may also be extended and far-reaching to solar-chemical storage under an appropriate design strategy.

Surface electronic state modulation promotes photoinduced aggregation and oxidation of trace CO for lossless purification of H2 stream

Although photogenerated hydroxyl radicals can oxidize CO without H2 consumption, the nonselective collision severely lowers photocatalytic photon utilization. We here demonstrate that electronic state modification of TiO2 resulted from magnesium doping can promote hydroxyl radical generation by weakening the adsorption of oxygen species and facilitating semiconductor-cocatalyst interfacial electron transfer. Importantly, the partial deprivation of electronic cloud from cationic sites can strengthen σ-donation and π-backdonation that synergistically promote the electrostatic interaction for aggregating CO in the vicinity of semiconductor. The resulted photocatalyst thus exhibits growing superiority over common counterpart in target reaction as CO concentration lowers. By these merits, CO in H2 stream can be reduced to < 1 × 10−6 with efficient photon utilization.

Oriented External Electric-Field Effects on the Activation of Aryl CO Bond in Anisole using Rh(PEP) (E=Al, B, Ga) Catalysts.

The present work reports a DFT-based mechanistic investigation of aryl C-O bond activation in anisole catalysed by a Rh-Al pincer-type complex at room temperature. The study is extended to analogues Rh-E complexes based on Group 13 elements (E=B/Ga). Our results show a preference for the heterolytic cleavage pathway over oxidative addition in the C-O bond activation. The calculated barriers range from 16 to 36 kcal/mol, following the order: E=Al<E=Ga<E=B. A strong correlation between the activation barriers and the local electric field (LEF) at the Rh metal centre for the studied Rh-E complexes was observed. Additionally, the ability of Oriented External Electric Field (OEEF) to lower the reaction barrier by applying the OEEF along the direction of electron reorganization, that is, "the reaction axis", was examined. Our results demonstrate the significant effect of applied OEEF on the aryl C-O bond activation in Rh-E systems. Furthermore, the effect of OEEF on the C-O bond activation using modified Rh-E (E=B, Al, or Ga) complexes, in which electronic structure modifications enable a more efficient barrier control by the OEEF, was showcased. Notably, applying a moderate field strength reduces the high reaction barrier for the Rh-B system by approximately 13 kcal/mol.

Work function tuning of directly grown graphene via ultraviolet–ozone treatment for electrode application in organic photovoltaic devices

Graphene is an efficient electrode material for flexible optoelectronic devices because of its high transmittance and electrical conductivity. A graphene film directly grown using plasma-enhanced chemical vapor deposition is suitable for electrode applications because it can be prepared on a glass substrate at relatively low temperatures without a transfer process from a metal catalyst. However, to obtain efficient optoelectronic devices using graphene electrodes, surface modification is necessary. Herein, we tuned the work function of a graphene electrode using ultraviolet (UV)-O3 treatment. The power conversion efficiency of organic photovoltaic devices was significantly increased by the UV-O3 treatment of the graphene anode. To investigate the origin of the improved device performance, the interface between the graphene anode and tetraphenyldibenzoperiflanthene (DBP) donor layer was analyzed via in situ ultraviolet photoelectron spectroscopy. The energy offset between the Fermi level of graphene and the highest occupied molecular orbital level of DBP was significantly reduced because of the increased work function. The results indicate that the electronic structure modification of graphene is of significant importance for fabricating efficient optoelectronic devices.

Optimized Electronic Modification of S-Doped CuO Induced by Oxidative Reconstruction for Coupling Glycerol Electrooxidation with Hydrogen Evolution

HighlightsS-doped CuO nanorod arrays (S-CuO/CF) constructed by sulfur leaching and oxidative remodeling strategy require only 1.23 and 1.33 V versus hydrogen evolution reaction (HER) to provide glycerol oxidation currents of 100 and 500 mA cm−2.S-CuO/CF shows satisfactory performance (at 100 mA cm−2, Vcell = 1.37 V) assembled as the anode in asymmetric coupled electrolytic cell of glycerol oxidation reaction and HER.The study identifies the key factors involved in the GOR reaction pathway, which include the C–C bond breaking and lattice oxygen deintercalation steps.

Optimizing the performance of Cs2AgBiBr6 based solar cell through modification of electron and hole transport layers

This work investigates the potential of Cs2AgBiBr6 as an absorber layer for solar cell applications and explores ways to advance the PV performance of cells by studying different electron transport layers (ETLs) and hole transport layers (HTLs). The energy band diagrams of the Cs2AgBiBr6 based cell are analyzed with different ETLs and HTLs to illustrate how electrons and holes flow within the cell. Specifically, one of the proposed cells substitutes TiO2 with chlorine passivated tin oxide (Cl@SnO2), while the other uses phenyl-C60 -butyric acid methyl ester on tin oxide (C60 -SnO2) as the ETL. The PV characteristics of the Cs2AgBiBr6-based solar cell is evaluated using SCAPS 1D. The PV performance parameters of Cs2AgBiBr6-based solar cells has been analyzed in search of optimum thickness of Cs2AgBiBr6 layer. Subsequently, the impact of bulk defect density in Cs2AgBiBr6 layer at the obtained optimum thickness i.e., 611 nm has also been explored. C60-SnO2 is found to have higher electron mobility, work function, and stability than Cl@SnO2, making it a better choice for the ETL. The resulting PV parameters for the cell Cl@SnO2/CS2AgBiBr6/Me4PACz are: VOC - 1.527 V, JSC - 10.42 mA/cm2, FF − 75.66%, and PCE - 12.08%. While the cell SnO2-C60/Cs2AgBiBr6/Me4PACz delivers PV parameters VOC- 1.53 V, JSC- 12.81 mA/cm2, FF - 79.15%, and PCE - 13.43%.

Boron Dopant Modulated Electron Localization of Tin Oxide for Efficient Electrochemical CO2 Reduction to Formate.

Sn-based electrocatalysts have great economic potential in the reduction of CO2 to HCOOH, while they still suffer from low current density, dissatisfactory selectivity, and poor stability. Inspired by electronic modification engineering, boron-doped SnO2 nanospheres (B-SnO2 ) are successfully synthesized to achieve high-efficiency CO2 reduction reaction (CO2 RR). It is found that the introduction of boron dopants can increase the number of active sites and facilitate the formation of the electron-rich Sn sites in its structure, thus enhancing the activation of CO2 molecules and reducing the energy barrier of *OCHO intermediates on the SnO2 surface. Thus, the B-doped SnO2 electrocatalyst exhibits a remarkable FEHCOOH above 90% within a broad potential window of -0.7 to -1.3V versus reversible hydrogen electrode (RHE) (600mV) and obtains the maximum value of 95.1% (the partial current density of HCOOH is 42.35mA cm-2 ) at -1V versus RHE. In conclusion, this work provides a novel strategy for optimizing the intrinsic properties of electrocatalysts for CO2 RR by the method of tuning the electronic structure.

Surface Electronic Structure Engineering of Manganese Bismuth Tellurides Guided by Micro-Focused Angle-Resolved Photoemission.

Modification of the electronic structure of quantum matter by ad atom deposition allows for directed fundamental design of electronic and magnetic properties. This concept is utilized in the present study in order to tune the surface electronic structure of magnetic topological insulators based on MnBi2 Te4 . The topological bands of these systems are typically strongly electron-doped and hybridized with a manifold of surface states that place the salient topological states out of reach of electron transport and practical applications. In this study, micro-focused angle-resolved photoemission spectroscopy (microARPES) provides direct access to the termination-dependent dispersion of MnBi2 Te4 and MnBi4 Te7 during in situ deposition of rubidium atoms. The resulting band structure changes are found to be highly complex, encompassing coverage-dependent ambipolar doping effects, removal of surface state hybridization, and the collapse of a surface state band gap. In addition, doping-dependent band bending is found to give rise to tunable quantum well states. This wide range of observed electronic structure modifications can provide new ways to exploit the topological states and the rich surface electronic structures of manganese bismuthtellurides.

The electronic structure modification and photocatalytic ability improvement of Rb0.9Nb1.625Mo0.375O5.62 β-pyrochlore compound

The photocatalytic ability of Rb0.9Nb1.625Mo0.375O5.62 UV-photocatalyst has been improved by electron structure modifications. The Rb0.75Cu0.15Nb1.625Mo0.375O5.6 and Rb0.8Mn0.1Nb1.625Mo0.375O5.7 modified compounds and Rb0.9Nb1.625Mo0.375O5.62/SnO2 heterostructure photocatalyst have been obtained under hydrothermal conditions. The crystal structure and elemental composition have been confirmed by X-ray diffraction analysis and X-ray microanalysis. The electron structure of the obtained samples has been investigated in comparison to initial one by diffuse reflection spectroscopy. All prepared samples possess the absorption in visible light range; however significant photocatalytic activity shows only Rb0.9Nb1.625Mo0.375O5.62/SnO2 heterostructure. The kinetic study of methylene blue photooxidation for Rb0.9Nb1.625Mo0.375O5.62/SnO2 at neutral pH have been investigated. It has been observed that the main oxidative species for dye oxidation are holes, hydroxyl radicals and superoxide radicals. The products of MB degradation have been determined by HPLC-MS method, and possible pathway of oxidation has been proposed.

Elucidating the alloying effect of PdAg/CNT catalysts on formic acid dehydrogenation with kinetic isotope effect

Formic acid has emerged as a promising liquid hydrogen carrier for addressing the transport and storage issues of hydrogen, owing to its high hydrogen density (4.4 wt.%) and easy-handling liquid phase. Therefore, the conversion of formic acid into hydrogen and vice versa is a significant technique. Despite the development of various metal alloy catalysts for efficient production of hydrogen from formic acid, it remains unclear how the metal alloy affects formic acid dehydrogenation from the mechanistic perspective. This study addresses this gap by investigating the alloy effect of Pd and Ag on formic acid dehydrogenation, using PdAg alloy nanoparticles supported on carbon nanotube catalysts. The PdAg alloy, analyzed using multiple characterization methods, demonstrated enhanced catalytic activity, which was maximized at a Pd:Ag molar ratio of 7:3. More importantly, temperature-dependent and kinetic isotope effect experiments demonstrated that the electronic modification of Pd by Ag improved its activity by promoting the cleavage of the CH bond of formic acid. The results suggest that the kinetic isotope effect would be a potent technique for elucidating the alloying effect, as well as providing a deeper understanding of the mechanism.

Electronic and Surface Modifications of Ni–Co–Fe Oxides: A Catalyst with Maximum Exposure of Fe Active Sites for Water Electrolysis

Electronic and Surface Modifications of Ni–Co–Fe Oxides: A Catalyst with Maximum Exposure of Fe Active Sites for Water Electrolysis

Surface oxygenation of non-oxide boosts oxidation activity on polyoxometalate subunits: An enhanced Venus flytrap mechanism

Typically, the interfacial wettability of catalysts, coupled with electronic modulation, is vitally controlled through surface treatments that boost catalytic performance. Simulation of the biomimetic catalytic process, for instance, a Venus Flytrap mechanism, is deemed as one of the most prospective but particularly challenging protocols to achieve efficient redox catalysis. Herein, a green oxidative desulfurization (ODS) system was readily fabricated, which constituted a modular moiety ionic liquid ([Bmim]Br) triggered PW12O40 (BHPW) anchored on oxygenated graphitic carbon nitride (o-CN). The BHPW/o-CN activates the reaction at 50 °C and is almost two times higher activity than that of BHPW/CN, combined ultrastability with handy synthetic availability for the deep oxidation of carbon–sulfur (C–S) bonds. Oxygen content serves as a descriptor for the catalytic performance. We demonstrate through mimicking CS2- and thiophene-TPD that the adsorption and pre-activation of C–S bonds on the hydrophilic CN surface are critically important for proceeding ODS reaction. Further, systematic characterization containing FT-IR, XPS, and UV–vis indicates the nature of the electron acceptor raised by the oxygen moieties for a plausible mechanism of C–S bonds and spilling to reactive centers. 1H NMR and H–D isotopic exchange analysis confirm the transfer of a proton from HPW to protonated [Bmim]– functional groups triggering the active sites for C–S bonds oxidation. Additionally, density functional calculation revealed the electronic modification of the CN properties shows conclusive activation and synergistic electron transfer mechanism for C–S. The catalyst realizes deep ODS of real diesel at 70 °C with negligible decay in successive cycles. Importantly, the extension of this protocol to other non-oxide (boron nitride) and active phases (molybdenum oxide and polyoxometalates) gives to the present widespread versatility and applicability.

Flexible organic-intercalated WSe2 hybrid: electronic structure modification and thermoelectric performance optimization

Two-dimensional tungsten selenide (WSe2) has great potential in thermoelectric (TE) applications, but dimensionality reduction results in a dramatic increase in thermal conductivity, which is not beneficial for improving thermoelectric performance. In this work, an electrochemical intercalation method is utilized to fabricate an organic-inorganic hybrid superlattice structure by decoupling the WSe2 layers without damaging the original bulk structure and then intercalating tetrabutylammonium (TBA) cations into the inorganic layers. The few-layer mixed-staging TBA-WSe2 hybrid with alternating stacking organic TBA cations and WSe2 inorganic layers possesses an electronic structure similar to that of the few-layer WSe2, which is beneficial for an enhanced Seebeck coefficient. The electron injection results in a considerable increase in the carrier concentration while the disorder in the mixed-staging structure succeeds in improving phonon scattering, leading to an enhanced figure-of-merit ZT of 0.25 at 340 K, which is three orders of magnitude higher than that of the pristine WSe2 single crystal and one of the highest ZT values among WSe2-based thermoelectric materials in recent years. This work may guide future research on dimensionality reduction in the electronic structures of bulk materials and the fabrication of flexible superlattice hybrids with considerable TE performance.

Steering the Titanic: One tertiary care children's hospital's experience navigating safe sleep for hospitalized infants

BackgroundSudden Unexpected Infant Death (SUID) is the leading cause of death in infants 1 month to 1 year of age in the United States. Despite extensive efforts in research and public education, rates of sleep-related infant death have plateaued since the late-1990s, largely due to unsafe sleep practices and environments. Local problemA multidisciplinary team assessed our institution's compliance with its own infant safe sleep policy. Data was collected on infant sleep practices, nurses' knowledge and training on the hospital policy, and teaching practices for parents and caregivers of hospitalized infants. Zero crib environments from our baseline observation met all the American Academy of Pediatrics recommendations for infant safe sleep. MethodsA comprehensive safe sleep program was implemented in a large pediatric hospital system. The purpose of this quality improvement project was to improve compliance with safe sleep practice from 0% to 80%, documentation of infant sleep position and environment every shift from 0% to 90%, and documentation of caregiver education from 12% to 90% within 24 months. InterventionsInterventions included revision of hospital policy, staff education, family education, environmental modifications, creation of a safe sleep taskforce, and electronic health record modifications. ResultsDocumented compliance with infant safe sleep interventions at the bedside improved from 0% to 88%, while documentation of family safe sleep education improved from 12% to 97% during the study period. ConclusionsA multifaceted, multidisciplinary approach can lead to significant improvements in infant safe sleep practices and education in a large tertiary care children's hospital system.

MXene-based Materials for Water Splitting: Synthesis and Modification.

With abundant metal site and tunable electronic structure, MXene is considered as a promising electrocatalyst for the conversion of energy molecules. In this review, the latest research progress on inexpensive MXene-based catalysts for water electrolysis is summarized. Typical preparation and modification methods and their advantages and disadvantages are briefly discussed, with a focus on the regulation and design of the surface interface electronic states, which improve the electrocatalytic performance of MXene-based materials. The main strategies for the electronic state modification include end-group modification, heteroatom doping, and heterostructure construction. Some limitations of MXene-based materials, which should be considered in the rational design of advanced MXene-based electrocatalyst, are also discussed. Finally, prospects for the rational design of Mxene-based electrocatalysts is proposed.