We report a recyclable and efficient catalyst system based on a nickel-benzene tricarboxylic acid metal–organic framework (Ni-BTC MOF) for the borylation of aryl halides, including aryl chlorides, with bis(pinacolato)diboron, affording aryl boronate esters in high yields (up to >99% yield) with high selectivity. This protocol demonstrates broad functional group tolerance. Catalyst can be recyclable up to four times, and gram-scale reactions further highlights the usefulness of this method. In situ EPR experiments confirmed the formation of catalytically active Ni(I) species.
Herein, we have designed and synthesized highly electocatalytically active 2D MoS2 nanosheets (NS), by a facile hydrothermal method, for hydrogen evolution reaction (HER).
We report two-dimensional VOx nanosheets containing multi-oxidation states (V5+, V4+, and V3+), prepared by a hydrothermal process for potential applications in resistive switching devices. The experimental results demonstrate a highly reproducible, electroforming-free, low SET bias bipolar resistive switching memory performance with endurance for more than 100 cycles maintaining OFF/ON ratio of ∼60 times. These devices show better memory performance as compared to previously reported VOx thin film based devices. The memory mechanism in VOx is proposed to be originated from the migration of oxygen vacancies/ions, an influence of the bottom electrode and existence of multi-oxidation states.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Electrical energy storage is an ever growing and important area of research in a modern technological world. The quest for energy storage materials is always in the limelight of research for the replacement of conventional environmentally toxic metal-based redox-active materials by organic molecules which provides an alternative for rechargeable batteries. Zinc/magnesium-based conducting polymer batteries attracted significant attention due to their high abundance, safety, and cost-effectiveness compared with lithium ion batteries (LIBs). This Review lays out an extensive overview of metal anodes like zinc/magnesium with conducting polymer cathode materials that possess high conductivity and theoretical capacitance. In addition, the complete redox behavior of polymer cathodes, the mechanism, the anode behavior in acidic and alkaline media, the effect of different electrolyte uses and drawbacks, the binders, and the housing of these batteries have been reviewed in detail. The socioeconomic impact, problems associated with dendrite, and passive layer formation with zinc/magnesium polymer cathode batteries, as well as future perspectives, will give a complete overview for the general reader as well as for experts working in these fields.
The use of molecular complex-modified electrodes presents avenues for their rational and simplistic design to serve as efficient catalysts in emerging electrocatalytic applications. Herein, three molecular electrocatalysts, CoLBr2, NiLBr2, and PdLBr2, were synthesized from the pyridine-functionalized N-heterocyclic carbene (NHC) ligand (HLBr) and physisorbed onto CC to obtain complex-modified free-standing electrodes. These complex-modified electrodes were investigated for their hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity in 1 M KOH. Among the complex-modified electrodes, the CoLBr2 electrode exhibited the best HER activity with an overpotential of −255 mV vs RHE at 10 mA/cm2 and a Tafel slope of 155 mV/dec. For the OER activity, the NiLBr2 electrode exhibited the best performance with an overpotential of 376 mV vs RHE at 10 mA/cm2 and a Tafel slope of 86 mV/dec. The bifunctional nature of the complex-modified free-standing CC electrodes enabled the assembly of a symmetric alkaline electrolyzer, i.e., CoLBr2//CoLBr2, with a cell voltage of 1.81 V at 10 mA/cm2. The post-stability analysis of the complex-modified electrodes revealed that the complexes possessed chemical stability despite undergoing long-term stability tests at high overpotentials. These findings authenticate the versatility of metal NHC complexes for fabricating molecularly modified free-standing electrodes for the HER, OER, and overall water splitting, paving the way for the development of sustainable energy conversion technologies.
Biohydrogen production from microalgae is a potential alternative energy source that is now intensively being researched. The complex natures of the biological processes involved have afflicted the accuracy of traditional modelling and optimization, besides being costly. Accordingly, machine learning algorithms have been employed to overcome setbacks, as these approaches have the capability to predict nonlinear interactions and handle multivariate data from microalgal biohydrogen studies. Thus, the review focuses on revealing the recent applications of machine learning techniques in microalgal biohydrogen production. The working principles of random forests, artificial neural networks, support vector machines, and regression algorithms are covered. The applications of these techniques are analyzed and compared for their effectiveness, advantages and disadvantages in the relationship studies, classification of results, and prediction of microalgal hydrogen production. These techniques have shown great performance despite limited data sets that are complex and nonlinear. However, the current techniques are still susceptible to overfitting, which could potentially reduce prediction performance. These could be potentially resolved or mitigated by comparing the methods, should the input data be limited.
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