Strategy of anchoring alloy nanoparticles made up of the efficient catalytic element (e.g., Ni, Fe) on dodecyl sulfate (DS^-)-intercalated NiFe layered double hydroxides (DS^--NiFe LDH) obtained by a convenient one-step hydrothermal coprecipitation method for essentially enhancing oxygen evolution reaction (OER) performance was proposed. The results of structural characterization indicate Pt₂FeNi alloy nanoparticles evenly distribute on the surface of DS^--NiFe LDH. The sizes of the Pt₂FeNi nanoparticles, closely related to their OER performance, could be well-controlled by adjusting the amount of H₂PtCl₆ addition. The composite structure of as-prepared product was stable during processes of synthesis, exfoliation, self-assembly, and subsequent electrocatalytic OER. Rigorous electrochemical test proving the contributing catalytic active sites was located at the interface between Pt₂FeNi and DS^--NiFe LDH, and the Ni and Fe were the major active elements while O atoms are adsorption sites. The formation of Pt₂FeNi nanoparticles could greatly prompt the reduction of Tafel slope. The best-performing Pt₂FeNi/DS^--NiFe LDH with a Pt content of 0.98 wt% achieved low overpotential of 204 mV at 10 mA cm⁻² and 262 mV at 50 mA cm⁻². This work provides a convenient and effective strategy to create additional active sites for enhancing OER performance of NiFe LDH and make contribution to its wide application.

Silicon (Si) is regarded as a promising anode material for next-generation lithium-ion batteries due to its ultrahigh theoretical capacity. However, the drastic volume change and the continuous solid electrolyte interphase (SEI) formation during the lithiation/delithiation process seriously hinder its practical application as commercial anodes. Herein, macrocyclic beta-cyclodextrin (β-CD) has been designed as the diffusion channel for lithium ions at the molecular scale. The diameter of molecular channel is approximately comparable with the solvated lithium ions, which enables the transport of lithium ions and prevents the penetration of solvent molecules. Moreover, the addition of β-CD changes the formation behavior of SEI layer and stabilizes the Si nanoparticles. The enhanced electrochemical performances in terms of fast kinetics and improved stability have been achieved. The Si anode with the particularly selected lithium-ion diffusion channel and stabilized SEI layer exhibits a high reversible capability of 2 562 mAh g⁻¹ after 50 cycles at the current density of 500 mA g⁻¹, 1 944 mAh g⁻¹ after 200 cycles at the current density of 1 A g⁻¹, and high rate performance. The novel strategy of molecular channel for lithium-ion diffusion offers new insights into the design of alloy-typed anode electrodes with high capacity for lithium-ion batteries.

A facile biomolecule-assisted hydrothermal route followed by calcination has been employed for the preparation of monoclinic yttrium oxysulfate hollow spheres doped with other rare-earth ions (Yb³⁺ and Eu³⁺ or Er³⁺). The formation of hollow spheres may involve Ostwald ripening. The resulting hybrid materials were used for upconversion applications. The host crystal structure allows the easy co-doping of two different rare-earth metal ions without significantly changing the host lattice. The luminescent properties were affected by the ratio and concentration of dopant rare-earth metal ions due to energy transfer and the symmetry of the crystal field. The type of luminescent center and the crystallinity of samples were also shown to have a significant influence on the optical properties of the as-prepared products.