Phase-dependent structural, optical, phonon and UV sensing properties of ZnS nanoparticles

Immunomodulatory zinc-based materials for tissue regeneration

Zinc(Zn)-based materials have contributed greatly to the rapid advancements in tissue engineering. The qualities they possess that make them so beneficial include their excellent biodegradability, biocompatibility, anti-bacterial activity, among and several others. Biomedical materials that act as a foreign body, will inevitably cause host immune response when introduced to the human body. As the osteoimmunology develops, the immunomodulatory characteristics of biomaterials have become an appealing concept to improve implant-tissue interaction and tissue restoration. Recently, Zn-based materials have also displayed immunomodulatory functions, especially macrophage polarization states. It can promote the transformation of M1 macrophages into M2 macrophages to enhance the tissue regeneration and reconstruction. This review covers mainly Zn-based materials and their characteristics, including metallic Zn alloys and Zn ceramics. We highlight the current advancements in the type of immune responses, as well as the mechanisms, that are induced by Zn-based biomaterials, most importantly the regulation of innate immunity and the mechanism of promoting tissue regeneration. To this end, we discuss their applications in biomedicine, and conclude with an outlook on future research challenges.

Metal Ion Cutting-Assisted Synthesis of Defect-Rich MoS2 Nanosheets for High-Rate and Ultrastable Li2S Catalytic Deposition

Active metal ions often show a strong cutting effect on the chemical bonds during high-temperature thermal processes. Herein, a one-pot metal ion cutting-assisted method was adopted to design defect-rich MoS_2-x nanosheet (NS)/ZnS nanoparticle (NP) heterojunction composites on carbon nanofiber skeletons (CNF@MoS_2-x/ZnS) via a simple Ar-ambience annealing. Results show that Zn²⁺ ions capture S^2- ions from MoS₂ and form into ZnS NPs, and the MoS₂ NSs lose S^2- ions and become MoS_2-x ones. As sulfur hosts for lithium-sulfur batteries (LSBs), the CNF@MoS_2-x/ZnS-S cathodes deliver a high reversible capacity of 1233 mA h g^-1 at 0.1 C and keep 944 mA h g^-1 at 3 C. Moreover, the cathodes also show an extremely low decay rate of 0.012% for 900 cycles at 2 C. Series of analysis indicate that the MoS_2-x NSs significantly improve the chemisorption and catalyze the kinetic process of redox reactions of lithium polysulfides, and the heterojunctions between MoS_2-x NSs and ZnS NPs further accelerate the transport of electrons and the diffusion of Li⁺ ions. Besides, the CNF@MoS_2-x/ZnS-S LSBs also show an ultralow self-discharge rate of 1.1% in voltage. This research would give some new insights for the design of defect-rich electrode materials for high-performance energy storage devices.

Waterborne fluorescent dual anti-counterfeiting ink based on Yb/Er-carbon quantum dots grafted with dialdehyde nano-fibrillated cellulose

Nanofibrillated cellulose (NFC) is becoming popular in the field of anti-counterfeiting material due to its favorable biocompatibility, renewability, and easy modification properties, which give it great potentials as carrier of carbon quantum dots (CQDs). Herein, we report an effective method to fabricate Yb and Er doped CQDs grafted onto dialdehyde NFC (DANFC). Owning to special rheological properties of NFC, a waterborne fluorescent dual anti-counterfeiting ink was rationally designed and successfully prepared by adding NFC to waterborne ink to form a stable network structure and increase the thixotropy and yield stress. The resulting CQDs exhibited both photoluminescence (PL) and up-conversion luminescence (UCPL), emitting blue and green fluorescence at excitation wavelengths of 370 and 980 nm, respectively. The study provides a novel method to prepare the waterborne fluorescent dual anti-counterfeiting ink based on Yb and Er doped CQDs/DANFC composites, which provides a reference for its application in printing and packaging industry.

Anchoring Black Phosphorus Nanoparticles onto ZnS Porous Nanosheets: Efficient Photocatalyst Design and Charge Carrier Dynamics

Black phosphorus nanoparticles (BP NPs) possess great advantages in photocatalysis owing to the rich surface active sites, extremely high carrier mobility, and strong visible-near-infrared light response. However, the complex preparation process, poor stability, and rapid carrier recombination restrict their successful application in photocatalysis. Herein, the above problems are resolved by preparing BP NPs through a facile sonication-assisted hydrothermal method. To further improve the stability and photocatalytic activity, BP NPs are tightly anchored onto ZnS to prepare ZnS-BP porous nanosheets. With the Zn-P coordination bond built between them, higher stability, enhanced carrier transport ability, and excellent hydrogen adsorption and desorption equilibrium of photocatalysts are achieved. An efficient and recyclable photocatalytic hydrogen evolution rate of 1561 μmol h^-1 g^-1 is obtained under visible-light irradiation, which is superior to that of previously reported BP-based photocatalysts. Besides, the photocatalytic mechanism is investigated based on the theoretical calculations and experimental characterizations. The charge transfer dynamics are studied by surface photovoltage (SPV), ultrafast transient absorption (TA), X-ray absorption spectra (XAS), electrochemical impedance spectroscopy (EIS), and steady-state photoluminescence (PL) spectra. This work set a reference for the design of high-performance BP-related nanomaterials in solar energy storage and conversion.