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The preparation of an electrocatalyst for the oxygen evolution reaction (OER) with high catalytic activity, good long-term durability and rapid reaction kinetics through interface engineering is of great significance. Herein, we have developed a bimetallic sulfide particle cluster-supported three-dimensional graphene aerogel (FeNiS@GA), which serves as an efficient electrocatalyst for OER, by a one-step hydrothermal method. Profiting from the synergy of the FeNiS particle cluster with high capacitance and GA with its three-dimensional porous nanostructure, FeNiS@GA shows a high specific surface area, large pore volume, low contact resistance, and decreases the electron and ion transport routes. FeNiS@GA exhibits outstanding OER activity (when the current density is 50 mA cm−2, the overpotential is 341 mV), low Tafel slope (63.87 mV dec−1) and remarkable stability in alkaline solutions, outperforming FeNiS, NiS@GA, FeS@GA and RuO2. Due to its simple synthesis process and excellent electrocatalytic performance, FeNiS@GA shows great potential to replace noble metal-based catalysts in practical applications. [ABSTRACT FROM AUTHOR]

Efficient non-noble metal bifunctional electrocatalysts can increase the conversion rate of electric energy in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Herein, a ball & sheet MoS2/Ni3S2 composite with wide-layer-spacing and high 1T-rich MoS2 is assembled on nickel foam (NF) via a two-step solvothermal method with polymeric sulfur (S-r-DIB) as the sulfur source. The obtained material serves as both the cathode and the anode toward overall water splitting in an alkaline electrolyte. The results proved that the interpenetration of MoS2/Ni3S2-p with a ball and sheet structure increased the material active surface area and exposed more catalytic active sites, which contributed to the penetration of solution and the transfer of charge/hydrion. Meanwhile, two different semiconductors of MoS2 and Ni3S2 along with the presence of ample active sulfur edge sites and few-layer, wide-layer-spacing structures of MoS2 lead to an outstanding electrocatalytic activity. In particular, the electrodes of MoS2/Ni3S2-p only need a battery voltage of 1.55 V at 10 mA cm−2. The bifunctional electrocatalyst MoS2/Ni3S2-p also shows excellent stability at large current densities during the electrochemical test. [ABSTRACT FROM AUTHOR]

The development of multifunctional electrocatalysts with rich resources, excellent performance, and stability is necessary for water splitting to achieve sustainable hydrogen and oxygen production. Herein, we report the preparation of a bifunctional coral-like nanostructured electrocatalyst (p-MoS2/NiS2) by in situ vulcanization of polymeric sulfur with a MoO3/Ni as the precursor. It is exciting that the whole preparation process of the electrocatalyst can be completed in a few hours. The as-fabricated multimetallic sulfide not only exhibits well-defined heterointerfaces and the defect-rich two-dimensional (2D) nanoconfiguration with high conductivity to overcome the poor hydrogen evolution reaction (HER) activity, but also promotes the formation of the 1T phase. The obtained p-MoS2/NiS2 nanostructures exhibit low overpotentials of −115 mV at −10 mA cm–2 and 337 mV at 100 mA cm–2 toward the HER and oxygen evolution reaction (OER), respectively, which surpass most of the previously reported bimetallic sulfide-based electrocatalysts. Benefiting from the stability of the hierarchical heterostructure and the coupling effect between the inner layer of NiS2 and outer layers of MoS2, the p-MoS2/NiS2 catalyst is endowed with high activity for water splitting. It can be used as a bifunctional electrocatalyst for water splitting with a cell voltage of 1.51 V at a current density of 10 mA cm–2. Overall, this work proposes a simple in situ vulcanization method to synthesize MoS2, which expands the interlayer spacing and realizes the coexistence of a metastable structure and metal doping. [ABSTRACT FROM AUTHOR]

Background: Ventilator dependency following coronary artery bypass grafting (CABG) is often associated with significant morbidity and mortality. However, few reports have focused on the independent risk factors for ventilator dependency following CABG. This study aimed to evaluate the independent risk factors for ventilator dependency following coronary artery bypass grafting (CABG). Methods: The relevant pre-, intra- and post-operative data of patients without a history of chronic obstructive pulmonary disease undergoing isolated CABG from January 2003 to December 2008 in our center were retrospectively analyzed. Elapsed time between CABG and extubation of more than 48 hours was defined as postoperative ventilator dependency (PVD). Results: The incidence of PVD was 13.8% (81/588). The in-hospital mortality in the PVD group was significantly higher than that in the non-PVD group (8.6% versus 2.4%, p=0.0092). Besides the length of ICU and hospital stay, PVD correlated with negative respiratory outcomes. The independent risk factors for PVD were preoperative congestive heart failure (OR=2.456, 95%CI 1.426-6.879), preoperative hypoalbuminemia (OR=1.353, 95%CI 1.125-3.232), preoperative arterial oxygen partial pressure (PO2) (OR=0.462, 95%CI 0.235-0.783) and postoperative anaemia (OR=1.541, 95%CI 1.231-3.783). Conclusions: Preoperative congestive heart failure, preoperative hypoalbuminemia, low preoperative PO2 and postoperative anaemia were identified as four independent risk factors for ventilator dependency following CABG.

Co-doped magnetic Mn3O4 was synthesized by the solvothermal method and adopted as an effective catalyst for the degradation of oxytetracycline (OTC) in water. Synergistic interactions between Co-Mn3O4 and Fe3O4 not only resulted in the enhanced catalytic activity through the activation of peroxymonosulfate (PMS) to degrade OTC but also made Fe3O4/Co-Mn3O4 easy to be separated and recovered from aqueous solution. 94.2% of OTC could be degraded within 60 min at an initial OTC concentration of 10 mg L−1, catalyst dosage of 0.2 g L−1, and PMS concentration of 10 mM. The high efficiency of OTC removal was achieved in a wider pH range of 3.0–10.0. Co (II), Co (III), Fe (II), Fe (III), Mn (II), Mn (III), and Mn (IV) on Fe3O4/Co-Mn3O4 were identified as catalytic sites based on XPS analysis. The free radical quenching experiments showed that O2•− radicals and 1O2 played the main role in the degradation process and the catalytic degradation of OTC involved both free radical and non-free radical reactions. Eventually, the intermediates of OTC degradation were examined, and the possible decomposition pathways were proposed. The excellent catalytic performances of Fe3O4/Co-Mn3O4 came from the fact that the large specific surface area could provide abundant active sites for the activation of PMS and the redistribution of inter-atomic charges accelerated the redox reactions of metal ions. The high degradation efficiency and rate constant of OTC in actual water samples indicated that Fe3O4/Co-Mn3O4 had a good practical application potential. [ABSTRACT FROM AUTHOR]