Search

Exploring efficient, low cost and stable electrocatalysts working at large current densities is crucial for upgrading the current industrial electrochemical water splitting. Herein, a novel FeS2/Fe–Ni3S2 heterostructure was successfully prepared via a simple one-step in situ hydrothermal vulcanization using F− regulation engineering. The FeS2/Fe–Ni3S2 heterostructure array exhibits low overpotentials for both the OER (180 mV @ 10 mA cm−2 and 300 mV @ 1 A cm−2) and the HER (105 mV @ 10 mA cm−2 and 344 mV @ 1 A cm−2) with high stability operating at 1 A cm−2 for 1000 h. In addition, the water-splitting system only needs 1.5 V to reach 10 mA cm−2 and shows prolonged stability of more than 1200 h at 1 A cm−2. The DFT calculations show that the electrons redistribute at the interface and favor the chemisorption of hydrogen and oxygen-containing intermediates. This work highlights a novel, low cost and practical electrode for industrial electrochemical water splitting. [ABSTRACT FROM AUTHOR]

Exploring earth‐abundant, highly effective, and stable electrocatalysts for overall water and urea electrolysis is urgent and essential for developing hydrogen energy technology. Herein, a simple self‐derivation method is used to fabricate a Fe‐doped Ni3S2 electrode. The electrode exhibits an impressive trifunctional catalyst, with low overpotentials of 290, 198, and 254 mV at 100 mA cm−2 for the oxygen evolution reaction (OER), urea oxidation reaction (UOR), and hydrogen evolution reaction (HER). The durability is higher than 3500 h (146 days) at 100 mA cm−2 for the OER without obvious change. In situ Raman spectra reveal the incorporation of Fe inhibited S dissolution and facilitates the catalyst reconstruction. The density functional theory calculations indicate that the doping of Fe optimizes the adsorption of the rate‐determining step and the d‐band center is closer to the Fermi level, which accelerates the OER process. The two‐electrode electrolyzer needs the cell voltages of only 1.76 and 1.57 V to achieve a current density of 100 mA cm−2 and remarkable durability for more than 500 h at 100 and 500 mA cm−2 for overall water and urea splitting. This work holds great promise for industrial water and urea splitting applications. [ABSTRACT FROM AUTHOR]

The discovery of drug–drug interactions (DDIs) that have a translational impact among in vitro pharmacokinetics (PK), in vivo PK and clinical outcomes depends largely on the quality of the annotated corpus available for text mining. We have developed a new DDI corpus based on an annotation scheme that builds upon and extends previous ones, where an abstract is fragmented and each fragment is then annotated along eight dimensions, namely, focus, polarity, certainty, evidence, directionality, study type, interaction type and mechanism. The guideline for defining these dimensions has undergone refinement during the annotation process. Our DDI corpus comprises 900 positive DDI abstracts and 750 that are not directly relevant to DDI. The abstracts in corpus are separated into eight categories of DDI or non-DDI evidence: DDI with pharmacokinetic (PK) mechanism, in vivo DDI PK, DDI clinical, drug–nutrition interaction, single drug, not drug related, in vitro pharmacodynamic (PD) and case report. Seven annotators, three annotators with drug–interaction research experience and four annotators with less drug–interaction research experience independently annotated the DDI corpus, where two researchers independently annotated each abstract. After two rounds of annotations with additional training in between, agreement improved from (0.79, 0.96, 0.86, 0.70, 0.91, 0.65, 0.78, 0.90) to (0.93, 0.99, 0.96, 0.94, 0.95, 0.93, 0.96, 0.97) for focus, certainty, evidence, study type, interaction type, mechanisms, polarity and direction, respectively. The novice-level annotators improved from 0.83 to 0.96, while the expert-level annotators stayed in high performance with some improvement, from 0.90 to 0.96. In summary, we achieved 96% agreement among each pair of annotators with regard to the eight dimensions. The annotated corpus is now available to the community for inclusion in their text-mining pipelines. Database URL https://github.com/zha204/DDI-Corpus-Database/tree/master/DDI%20corpus [ABSTRACT FROM AUTHOR]

Abstract: Titanium dioxide is a promising photoanode material for water oxidation, but it is substantially limited by its poor efficiency in the visible light range. Herein, an innovative carbon/nitrogen coimplantation method is utilized to realize the “Midas touch” transformation of TiO2 nanowire (NW) arrays for photoelectrochemical (PEC) water splitting in visible light. These modified golden–yellow rutile TiO2 NW arrays (C/N‐TiO2) exhibit remarkably enhanced absorption in visible light regions and more efficient charge separation and transfer. As a result, the photocurrent density of carbon/nitrogen co‐implanted TiO2 under visible light (>420 nm) can reach 0.76 mA cm−2, which far exceeds the value of 3 µA cm−2 seen for pristine TiO2 nanowire arrays at 0.8 V versus Ag/AgCl. An incident photon to electron conversion efficiency of ≈14.8% is achieved at 450 nm on C/N‐TiO2 without any other cocatalysts. The ion implantation doping approach, combined with codoping strategies, is proved to be an effective strategy for enhancing the photoelectrochemical conversion and can enable further improvement of the PEC water‐splitting performance of many other semiconductor photoelectrodes. [ABSTRACT FROM AUTHOR]

Drug-drug interactions (DDIs) are a common cause of adverse drug events (ADEs). The electronic medical record (EMR) database and the FDA's adverse event reporting system (FAERS) database are the major data sources for mining and testing the ADE associated DDI signals. Most DDI data mining methods focus on pair-wise drug interactions, and methods to detect high-dimensional DDIs in medical databases are lacking. In this paper, we propose 2 novel mixture drug-count response models for detecting high-dimensional drug combinations that induce myopathy. The "count" indicates the number of drugs in a combination. One model is called fixed probability mixture drug-count response model with a maximum risk threshold (FMDRM-MRT). The other model is called count-dependent probability mixture drug-count response model with a maximum risk threshold (CMDRM-MRT), in which the mixture probability is count dependent. Compared with the previous mixture drug-count response model (MDRM) developed by our group, these 2 new models show a better likelihood in detecting high-dimensional drug combinatory effects on myopathy. CMDRM-MRT identified and validated (54; 374; 637; 442; 131) 2-way to 6-way drug interactions, respectively, which induce myopathy in both EMR and FAERS databases. We further demonstrate FAERS data capture much higher maximum myopathy risk than EMR data do. The consistency of 2 mixture models' parameters and local false discovery rate estimates are evaluated through statistical simulation studies. [ABSTRACT FROM AUTHOR]

Defect engineering is an important method for enhancing photocatalytic performance. In article no. 1800298, Zhaowu Wang, Feng Ren, and co‐workers successfully design and prepare a defective g‐C3N4 photocatalyst via ion irradiation technology, achieving simultaneous introduction of C‐ and N‐ vacancies and the control of vacancy concentration, thus realizing a remarkable improvement in photocatalytic hydrogen production performance. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g‐C3N4) is reported to be a promising metal‐free semiconductor for photocatalytic water splitting. However, the performance of g‐C3N4 is substantially limited by its insufficient visible‐light absorption and low photogenerated charge carrier separation efficiency. In this work, an innovative method (ion irradiation) to efficiently introduce both defined C‐ and N‐vacancies (VC and VN) simultaneously into g‐C3N4 nanosheets are explored. Unlike traditional chemical methods, by controlling He+ ion fluence, tunable vacancy concentrations are able to be obtained in g‐C3N4. Defect‐engineered g‐C3N4 shows highly improved performance under optimized conditions, the defective g‐C3N4 exhibits a significantly higher (2.7‐fold) hydrogen evolution rate of 1271 µmol g−1 h−1 than that of the g‐C3N4 nanosheets under visible light (λ > 420 nm) illumination. Meanwhile, the defective g‐C3N4 exhibits a significantly enhanced (threefold) photocurrent density as photoanodes for photoelectrochemical (PEC) water splitting. Further characterizations show that the enhanced visible light absorption and an extended charge carrier lifetime, can be ascribed to the presence of C‐ and N‐ vacancies. These experimental results are in line with density functional theory (DFT) calculations. Therefore, the present work shows that defect‐engineering on g‐C3N4 using ion irradiation technique, is an effective, controllable, and defined approach to improve the photocatalytic and PEC water splitting performance of g‐C3N4. Defective g‐C3N4 photocatalysts are successfully prepared by ion irradiation technology, achieving simultaneous introduction of C– and N– vacancies and the control of vacancy concentration. The C– and N– vacancies help to enhance the absorption of visible light and the separation efficiency of photogenerated carriers, respectively, thus realizing the remarkable improvement of photocatalytic hydrogen production performance. [ABSTRACT FROM AUTHOR]

Nanostructured Si as the high efficiency photoelectrode material is hard to keep stable in aqueous for water splitting. Capping a passivation layer on the surface of Si is an effective way of protecting from oxidation. However, it is still not clear in the different mechanisms and effects between insulating oxide materials and oxide semiconductor materials as passivation layers. Here, we compare the passivation effects, the photoelectrochemical (PEC) properties, and the corresponding mechanisms between the HfO2/nanoporous-Si and the TiO2/nanoporous-Si by I-V curves, Motte-schottky (MS) curves, and electrochemical impedance spectroscopy (EIS). Although the saturated photocurrent densities of the TiO2/nanoporous Si are lower than that of the HfO2/nanoporous Si, the former is more stable than the later. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is an obstacle to the electrocatalytic water splitting due to its unique four-proton-and-electron-transfer reaction process. Many methods, such as engineering heterostructure and introducing oxygen vacancy, have been used to improve the catalytic performance of electrocatalysts for OER. Herein, the above two kinds of regulation are simultaneously realized in a catalyst by using unique ion irradiation technology. A nanosheet structured NiO/NiFe 2 O 4 heterostructure with rich oxygen vacancies converted from nickel-iron layered double hydroxides by Ar + ions irradiation shows significant enhancement in both OER and hydrogen evolution reaction performance. Density functional theory (DFT) calculations reveal that the construction of NiO/NiFe 2 O 4 can optimize the free energy of O * to OOH * process during OER reaction. The oxygen vacancy-rich NiO/NiFe 2 O 4 nanosheets have an overpotential of 279 mV at 10 mA cm -2 and a low Tafel slope of 42 mV dec -1 . Moreover, this NiO/NiFe 2 O 4 electrode shows an excellent long-term stability at 100 mA cm -2 for 450 h. The synergetic effects between NiO and NiFe 2 O 4 make NiO/NiFe 2 O 4 heterostructure have high conductivity and fast charge transfer, abundant active sites, and high catalytic reactivity, contributing to its excellent performance., (© 2021 Wiley-VCH GmbH.)

Nanostructured Si as the high efficiency photoelectrode material is hard to keep stable in aqueous for water splitting. Capping a passivation layer on the surface of Si is an effective way of protecting from oxidation. However, it is still not clear in the different mechanisms and effects between insulating oxide materials and oxide semiconductor materials as passivation layers. Here, we compare the passivation effects, the photoelectrochemical (PEC) properties, and the corresponding mechanisms between the HfO 2 /nanoporous-Si and the TiO 2 /nanoporous-Si by I-V curves, Motte-schottky (MS) curves, and electrochemical impedance spectroscopy (EIS). Although the saturated photocurrent densities of the TiO 2 /nanoporous Si are lower than that of the HfO 2 /nanoporous Si, the former is more stable than the later.

Porous photoelectrodes show high efficiency in hydrogen production by water splitting. However, fabrication of porous nanorods is usually difficult. Here, we report a simple approach to fabricate a kind of novel porous rutile titanium dioxide nanorod array by an advanced ion implantation method using multiple-energy helium ion implantation and subsequent annealing. The porous nanostructure enhances the photoelectrochemical performance of the titanium dioxide nanorod array photoelectrodes under Uv-visible light illumination, where the highest photocurrent density was relatively about 10 times higher than that of the pristine titanium dioxide nanorod array. The formation of nanocavities mainly contributes to the enhancement of the photocurrent density by trapping holes inside to separate the charge carriers. The study demonstrates that ion implantation could be an effective approach to develop novel porous nanostructural photoelectrodes for the application of hydrogen production.