Search

Nickel-based non-noble-metal materials have emerged as promising catalysts for electrochemical hydrogen production in view of their attractive intrinsic activities, electrical properties and low cost. Exploring new candidates for further improving the performances of nickel-based catalysts and understanding the structure–activity relationship are still necessary to reduce the overpotential of the hydrogen evolution reaction (HER) thus advancing their application in electrochemical water splitting. Herein, we developed a facile two-step self-templated strategy for fabricating a three-dimensional (3D) nanoporous nickel/vanadium oxide (Ni/V2O3) nanoplate assembly as a new efficient catalyst for alkaline HER. It is found that by controllably annealing the Ni–V–O assembly as a single precursor, Ni and V2O3 components are uniformly integrated in the nanoporous composite, showing a synergistically enhancing effect on the HER. The resulting 3D nanoporous structure not only creates numerous active sites accessible for the HER but also provides a conductive open network towards efficient electron/mass transport. Consequently, the nanoporous Ni/V2O3 nanoplate assembly exhibits excellent catalytic performance for alkaline HER in terms of a low overpotential of 61 mV at 10 mA cm−2 and a small Tafel slope of 79.7 mV dec−1 together with excellent long-term durability. These findings provide new insights into good design and construction of other highly active catalysts for diverse applications. [ABSTRACT FROM AUTHOR]

Exploring the applications of two dimensional layered Ti3C2X2 (X = OH, F) is of great importance because of its excellent physical and chemical properties. Herein, we report the synthesis of the bimetallic catalyst PtyCo1−y/Ti3C2X2via a facile one-pot approach using Ti3C2X2 as the support. The in situ synthesized PtyCo1−y/Ti3C2X2 is subsequently applied as a catalyst for hydrogen evolution from the hydrolysis of ammonia borane at 25 °C. Experimental results show that Pt0.08Co0.92/Ti3C2X2 exhibits excellent catalytic activity for the hydrolysis of ammonia borane with a high hydrogen generation rate of 100.7 L H2 (min gPt)−1 and turnover frequency of 727 mol H2 (min molPt)−1 because of the synergistic effect between Pt and Co. Moreover, Pt0.08Co0.92/Ti3C2X2 could be recovered from the reaction mixture by a magnet and recycled at least seven times, thus showing its high recycling efficiency. [ABSTRACT FROM AUTHOR]

Wenxin Keli (WK), a Chinese patent medicine, is known to be effective against cardiac arrhythmias and heart failure. Although a number of electrophysiological findings regarding its therapeutic effect have been reported, the active components and system-level characterizations of the component-target interactions of WK have yet to be elucidated. In the current study, we present the first report of a new protective effect of WK on suppressing anti-arrhythmic-agent-induced arrhythmias. In a model of isolated guinea pig hearts, rapid perfusion of quinidine altered the heart rate and prolonged the Q-T interval. Pretreatment with WK significantly prevented quinidine-induced arrhythmias. To explain the therapeutic and protective effects of WK, we constructed an integrated multi-target pharmacological mechanism prediction workflow in combination with machine learning and molecular pathway analysis. This workflow had the ability to predict and rank the probability of each compound interacting with 1715 target proteins simultaneously. The ROC value statistics showed that 97.786% of the values for target prediction were larger than 0.8. We applied this model to carry out target prediction and network analysis for the identified components of 5 herbs in WK. Using the 124 potential anti-arrhythmic components and the 30 corresponding protein targets obtained, an integrative anti-arrhythmic molecular mechanism of WK was proposed. Emerging drug/target networks suggested ion channel and intracellular calcium and autonomic nervous and hormonal regulation had critical roles in WK-mediated anti-arrhythmic activity. A validation of the proposed mechanisms was achieved by demonstrating that calaxin, one of the WK components from Gansong, dose-dependently blocked its predicted target Ca V 1.2 channel in an electrophysiological assay.