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Engineering catalytic sites at the atomic level provides an opportunity to understand the catalysts active sites, which is vital to the development of improved catalysts. Here we show a reliable and tunable polyoxometalate template-based synthetic strategy to atomically engineer metal doping sites onto metallic 1T-MoS2, using Anderson-type polyoxometalates as precursors. Benefiting from engineering nickel and oxygen atoms, the optimized electrocatalyst shows great enhancement in the hydrogen evolution reaction with a positive onset potential of ~ 0 V and a low overpotential of -46 mV in alkaline electrolyte, comparable to platinum-based catalysts. First-principles calculations reveal co-doping nickel and oxygen into 1T-MoS2 assists the process of water dissociation and hydrogen generation from their intermediate states. This research will expand on the ability to improve the activities of various catalysts by precisely engineering atomic activation sites to achieve significant electronic modulations and improve atomic utilization efficiencies.

Rechargeable aqueous zinc-ion batteries (AZIBs) have garnered widespread attention due to their low cost, non-flammability, eco-friendliness, and abundant anode element content, with the potential to supplant lithium-ion batteries. Nevertheless, their development is hindered by zinc dendrite growth, corrosion passivation, the hydrogen evolution reaction (HER), and active material decomposition, severely impairing the cycling lifespan and coulombic efficiency of AZIBs. As a cathode material, sulfur offers superior theoretical capacity, non-toxicity, and lower cost compared to traditional aqueous zinc-ion battery active materials, thus compensating for the shortcomings of low discharge capacity and insufficient overall energy density in AZIBs. Although research on aqueous zinc-sulfur batteries (AZSBs) is relatively scarce, their exceptional performance has yielded outstanding results. This paper first reviews the cathode materials and reaction mechanisms of aqueous zinc–sulfur batteries, and then systematically analyzes the pertinent electrochemical performance data following the latest research on electrolyte modification and additive engineering. Subsequently, we discuss and analyze potential solutions to the existing impediments in zinc–sulfur batteries. Finally, based on an analysis of current research findings, we propose future research directions with the aim of providing inspiration to overcome the latent challenges facing aqueous zinc-sulfur batteries. [ABSTRACT FROM AUTHOR]

Both polyoxometalates (POMs) and organic small molecular catalysts show excellent performance in chemical synthesis. The incorporation of nanoscale POMs and organocatalysts allows the full expression of their respective merits and enables elusive reactions to be achieved in one catalytic system. However, the covalent combination of such two components has been rarely explored. Here, we have successfully designed and synthesized a bifunctional nanomolecular catalyst L -Pro-Mn-Anderson by grafting L -proline onto an Mn-Anderson POM for the first time, and catalytic experiments show that L -Pro-Mn-Anderson can realize the one-pot alcohol oxidation/three-component reaction to synthesize two types of heterocyclic compounds (5-aryl-pyrimido[4,5-b]quinoline-dione derivatives and pyrazolo[3,4-b] pyridine derivatives) in high yields up to 97%. The detailed characterization of the catalyst and the catalytic mechanism has shown that L -Pro-Mn-Anderson exhibits synergistic effects that combine both organic and inorganic catalytic functions, and the covalent linkage improves the overall redox activity of the molecular catalyst. This study opens up a new way for the design and application of covalently combined organic–inorganic molecular catalysts toward de novo organic synthesis. [ABSTRACT FROM AUTHOR]

A Keggin-type polyoxometalate-based crystalline complex, [(SiMo12O40)Cu6(2,2′-bipy)6(Mo6O22)] (complex 1), has been prepared by using a Waugh-type polyoxometalate building block [MnMo9O32]6−, and for the first time, Waugh-type polyoxometalate was converted to a Keggin-type structure under hydrothermal conditions by using a Teflon-lined reactor with glass vials. The synthesized complex was characterized by single-crystal and powder X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, and elemental analysis. Structural characterization results show that complex 1 comprises Keggin-type [SiMo12O40]4− anions and [Cu6(2,2′-bipy)6(Mo6O22)]4+ cation moieties composed of isopolymolybdates with 2,2′-bipy-coordinated copper ions, leading to a three-dimensional (3D) supramolecular network. This polyoxometalate assembly exhibits excellent photocatalytic properties and good cyclic stability for the photodegradation of methylene blue (MB) dye. In addition, the experimental results demonstrate that complex 1 also possesses outstanding electrocatalytic activity for nitrite reduction. [ABSTRACT FROM AUTHOR]