Sulfides are promising anode candidates because of their relatively large theoretical discharge/charge specific capacity and pretty small volume changes, but suffers from sluggish kinetics and structural instability upon cycling. Phase engineering can be designed to overcome the weakness of the electrochemical performance of sulfide anodes. By choosing nickel sulfides (α‐NiS, β‐NiS, and NiS2) supported by reduced graphene oxide (rGO) as model systems, it is demonstrated that the nickel sulfides with different crystal structures show different performances in both sodium‐ion and potassium‐ion batteries. In particular, the α‐NiS/rGO display superior stable capacity (≈426 mAh g−1 for 500 cycles at 500 mA g−1) and exceptional rate capability (315 mAh g−1 at 2000 mA g−1). The combined density functional theory calculations and experimental studies reveal that the hexagonal structure is more conducive to ion absorption and conduction, a higher pseudocapacitive contribution, and higher mechanical ability to relieve the stress caused by the volume changes. Correspondingly, the phase engineered nickel sulfide coupled with the conducting rGO network synergistically boosts the electrochemical performance of batteries. This work sheds light on the use of phase engineering as an essential strategy for exploring materials with satisfactory electrochemical performance for sodium‐ion and potassium‐ion batteries.

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Low photocatalytic CeO2/TiO2 nanocomposite particles with high UV attenuation and reduced ROS generation for application in sunscreen products.

Lithium metal batteries have recently gained tremendous attention owing to their high energy capacity compared to other rechargeable batteries. Nevertheless, lithium (Li) dendritic growth causes low Coulombic efficiency, thermal runaway, and safety issues, all of which hinder the practical application of Li metal as an anodic material. In this review, the failure mechanisms of Li metal anode are described according to its infinite volume changes, unstable solid electrolyte interphase, and Li dendritic growth. The fundamental models that describe the Li deposition and dendritic growth, such as the thermodynamic, electrodeposition kinetics, and internal stress models are summarized. From these considerations, porous carbon-based frameworks have emerged as a promising strategy to resolve these issues. Thus, the main principles of utilizing these materials as a Li metal host are discussed. Finally, we also focus on the recent progress on utilizing one-, two-, and three-dimensional carbon-based frameworks and their composites to highlight the future outlook of these materials.

Size and shape-controlled two-dimensional (2D) superparamagnetic maghemite (γ-Fe2O3) quantum flakes (MQF) with high surface area and mesoporosity prepared by facile hydrothermal synthesis and calcination for biological applications. These quantum flakes...

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A deficiency in the human antioxidant system to scavenge free radicals results in mounting oxidative stress, causing various pathological conditions including immune system constraints. To support an underperforming antioxidant system and regulate homeostatic function, efficient and biocompatible reactive oxygen species (ROS) scavengers may be employed. At present, metal oxide-based antioxidants nanoparticles are of fundamental interest because of their smart surface property tailoring. A spray precipitation method was employed in this work to develop a strained and defect rich lanthanum oxide (La 2 O 3 ) nanostructure. A contraction in d-spacing and distortion in planes and vacancies were observed in the nanostructure, causing microstrain as verified by the William-Hall uniform deformation model (UDM). Photocatalytic activity was evaluated against commercial La 2 O 3 and Evonik Aeroxide TiO 2 P25 via dye degradation experiments. A 30% degradation reduction confirmed the ability of the nanostructure to scavenge free radicals generated by P25 upon ultraviolet (UV) irradiation. Compared to the commercial La 2 O 3 , the nanostructured La 2 O 3 showed an increase in UV absorption (200−400) nm due to a decrease in the optical band gap. A positive surface charge of the nanoparticles was observed from zeta potential measurements, suggesting sufficient colloidal stability. In vitro toxicity studies toward the nonmalignant human keratinocyte cell line (HaCaT) over a 24 h treatment period with the La 2 O 3 nanoparticles exhibited no toxicity in comparison with the control and ZnO nanoparticles. The antioxidant properties of the nanoparticles were investigated by a dichlorofluorescein (DCF)-based assay which revealed a decrease in intracellular ROS in comparison with Nacetylcysteine (NAC) and H 2 O 2 . In addition, confocal microscopy imaging showed the internalization of the nanoparticles and subsequent DCF intensity change between the treated and untreated cells, as supported by flow cytometry analysis. Our findings suggest that defect-rich La 2 O 3 nanoparticles could be used effectively as active inorganic UV filter and fluorescent contrast agent owing to their biocompatible antioxidant properties.

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