Functional Materials Letters

For an effective promotion of ZnO nanostructure in photocatalytic H₂ evolution, this work aims to build a 3D ZnO/ZnS sheet@ZnO/ZnS nanotube (3D ZSN) structure with Eosin Y to realize the efficient hydrogen production. The combination of the 3D ZSN unique structure and Eosin Y greatly promotes the hydrogen production performance. The H₂ production yield of 3D ZSN holds 9.321 mmol ⋅ g${}^{-1}$ ⋅ h${}^{-1}$, where the hydrogen production efficiency is about 1.64 times higher than that of without Eosin Y. The augmentation mechanism is to use the unique structure of three-dimensional bar and Eosin Y acts as a support substrate to give and obtain electrons appropriately, which will provide a new approach to improving the photocatalytic H₂ production efficiency of a photocatalyst.

A novel Sr₂Al₂SiO₇:Eu${}^{2+}$, Dy${}^{3+}$ long-persistent luminescence (LPL) glass–ceramic has been successfully synthesized by the recrystallization-melting method in the SrO-Al₂O₃-SiO₂-B₂O₃-Li₂ O glass system. The glass–ceramic form enhances the plasticity of the material compared to traditional Sr₂Al₂SiO₇:Eu${}^{2+}$, Dy${}^{3+}$ phosphorescence powders. Additionally, the Dy${}^{3+}$ ions serve a dual role as fluorescence emission centers and sensitizers for afterglow. By controlling the concentration of Dy${}^{3+}$, the characteristic fluorescence intensity can be adjusted to achieve color-tunable photoluminescence. Besides, Dy${}^{3+}$ ions, as trap centers, capture the electrons, resulting in a longer afterglow than the Eu${}^{2+}$ singly doped sample. After exposure to ultraviolet light, the initial brightness intensity of the Dy:Eu = 16:1 sample increases to 1525 mcd/m², and the emission lasts for 30 min. These optimized bulk materials, with unique luminous properties, have potential applications in future optoelectronic devices.

As green anode materials with wide distribution, controllable cost, and diversified structure, carbon materials have received more attention. In this paper, iodine- and nitrogen-co-doped carbon flower materials were prepared. The flower-like structure of the material ensures the rapid diffusion of lithium ions, and the synergistic effect of iodine and nitrogen atoms improves the pore size distribution, the conductivity and the active sites of carbon materials realizing the high ion storage and the fast charge diffusion. As the anode material of lithium-ion batteries, the iodine- and nitrogen-co-doped carbon flower could have the capacitance of 410 mAh g${}^{-1}$ at the current density of 0.1 A g${}^{-1}$ after 150 cycles and 181 mAh g${}^{-1}$ at the high current density of 2.0 A g${}^{-1}$ after 1000 cycles. The results of electrochemical impedance spectroscopy, kinetics, and GITT show this material has fast charge transport kinetics and excellent rate performance.

High-performance flexible Bi₂Te₃-based thin films carry significant promise for future portable and wearable thermoelectric devices. In this study, a series of Bi${}_{0.5}$Sb${}_{1.5}$Te₃ thin films were deposited on polyimide substrates under different RF magnetron sputtering powers from 60 W to 140 W. The crystallinity, (00$l$) preferential orientation and atomic composition can be effectively modulated by varying the sputtering power. Benefiting from the synchronous enhancements of the electrical conductivity (mostly due to the enhanced carrier mobility) and Seebeck coefficient, the film deposited under the sputtering power 100 W presents the best PF of 12.86 $\mu$W cm${}^{-1}$K${}^{-2}$ at 360 K and the highest average PF of 11.25 $\mu$W cm${}^{-1}$K${}^{-2}$ in the temperature range of 300–560 K, which are much better than those of the films deposited under other sputtering powers.

The application of microwave technology has penetrated all aspects of life, but also lead to the electromagnetic pollution, therefore the research of high efficiency microwave absorption materials has been widely concerned. In this work, a new type of Al based CAU-10-H MOF was prepared by hydrothermal method. The particles were polyhedral in size of 2 $\mu$m. After high temperature annealing, the interplanar spacing increased with the annealing temperature, and the lattice structure was destroyed at 400${}^{\circ }$C. CAU-Al/rGO aerogels were prepared by freeze-drying of hydrogels. With the increase of CAU-Al content and the annealing temperature, the carbon crystallinity decreases, and the pores of the aerogels became larger and fluffier. The real parts of permittivity of CAU-Al/rGO aerogels were between 5 and 30, which can be tuned by the annealing temperature and CAU-Al content. For the microwave absorption performance, the CAU-Al/rGO aerogel with a ratio of 3:1 achieved the minimum reflection loss of − 37.8 dB at 3 mm. Moreover, the CAU-Al/rGO aerogels showed a wide effective bandwidth, which reached 5.1 GHz under the thickness of 2.5 mm. Therefore, the CAU-Al/rGO aerogels could be used as a kind of broadband microwave absorber with excellent microwave absorption performance.

Recently, ${\mathrm{\text{Ag}}}_2\mathrm{\text{S}}$-based compounds have aroused intensive research interest due to their metal-like ductility, high shape-conformability, and decent thermoelectric (TE) performance at room temperature. The melting–annealing method is commonly adopted to prepare ${\mathrm{\text{Ag}}}_2\mathrm{\text{S}}$-based compounds. Compared with the melting–annealing method, the mechanical alloying (MA) method has the advantages of short period and low cost, but it has not been adopted to prepare ductile ${\mathrm{\text{Ag}}}_2\mathrm{\text{S}}$-based compounds. Herein, we successfully prepare the ductile ${\mathrm{\text{Ag}}}_2{\mathrm{\text{S}}}_{0.7}{\mathrm{\text{Te}}}_{0.3}$ compound by using the MA method. The as-prepared ${\mathrm{\text{Ag}}}_2{\mathrm{\text{S}}}_{0.7}{\mathrm{\text{Te}}}_{0.3}$ products are small spheres with a diameter of several millimeters rather than the powders. These spheres are phase pure with homogeneous element distribution and good deformability. After the consolidation process at 773 K, the ${\mathrm{\text{Ag}}}_2{\mathrm{\text{S}}}_{0.7}{\mathrm{\text{Te}}}_{0.3}$ prepared by using the MA method shows good ductility like that prepared by the melting-annealing method. Finally, a maximum bending strain of above 15%, a maximum compressive strain of above 40%, and a maximum figure-of-merit (zT) of 0.5 are obtained, indicating the feasibility of MA in the preparation of ductile TE compounds.

To integrate pH/NIR dual-responsive drug release mechanisms with multimodal therapies for effective treatment of malignant tumors, hierarchical hydroxyapatite (HAp)/AuNR hybrid microspheres, consisting of a hollow HAp core and an AuNR shell, were facilely synthesized using phytic acid (IP6) as a sustainable template and phosphorus source. Urea served as the pore-forming agent and pH regulator during the synthesis process. The integration of AuNR into multifunctional HAp systems enabled NIR-responsive controllable drug release and photothermal ablation specifically at the tumorigenic site. The aggregation of AuNR within and outside the hybrid microspheres effectively hinders the release of doxorubicin hydrochloride (DOX) from the hollow HAp microspheres, mitigating the initial burst release and minimizing side effects. The results indicate that the h-HAp/AuNR hybrid exhibited remarkable drug loading efficiency (159.9$\mu$g ⋅ mg${}^{-1}$), with drug release exhibiting pH-dependent behavior due to the dissolution of HAp in acidic environments. Furthermore, MTT assays and fluorescence imaging demonstrate that DOX-loaded h-HAp/AuNR significantly enhance antitumor efficacy, achieving a cell survival rate of 12.3% at a concentration of 100$\mu$g ⋅ mL. This integrated system offers a promising approach for combined chemotherapeutic delivery and NIR photothermal therapy.

In this work, ${\mathrm{\text{WO}}}_3$ quantum dots grow in situ on the synthesized ultra-thin ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4$ nanosheets, ultimately forming a type of tightly bound 2D/0D Z-type heterojunctions. It was found that ${\mathrm{\text{WO}}}_3$ quantum dots were closely combined with ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4$ nanosheets through SEM and TEM measurements. XRD, IR, and XPS characterization proved a ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4/{\mathrm{\text{WO}}}_3$ heterojunction material was formed. The construction of ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4/{\mathrm{\text{WO}}}_3$ heterojunctions enhanced visible light absorption, improved carrier separation efficiency, and reduced charge transfer resistance. Photocatalytic hydrogen production tests showed that the hydrogen production rate of 20% ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4/{\mathrm{\text{WO}}}_3$ composite materials was 2.8 times that of the original ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4$, and the hydrogen production amount within 3h was 3.7 times that of the original ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4$. Photocatalytic degradation of Rhodamine B and 4-chlorophenol under visible light irradiation showed that compared with ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4$, the photocatalytic degradation efficiency of 20% ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4/{\mathrm{\text{WO}}}_3$ composite materials was enhanced. The results reveal that the special structured ${\mathrm{\text{g-C}}}_3{\mathrm{\text{N}}}_4/{\mathrm{\text{WO}}}_3$ composite materials have excellent photocatalytic activity, which can not only efficiently produce hydrogen but also efficiently degrade organic pollutants, providing an important reference for solving energy crises and environmental problems.

Gel polymer electrolyte (GPE) based on polymer matrix of lignocellulose and gelatinized potato starch is prepared, and elemental sulfur is introduced as an additive for the first time. The polymer matrix has shown excellent performances including liquid electrolyte uptake, tensile strength and thermal stability. The ionic conductivity and electrochemical stability window of the corresponding GPE are improved with the introduction of the elemental sulfur. Furthermore, the addition of elemental sulfur can be reduced into short-chain ${\mathrm{\text{Li}}}_2\mathrm{\text{S}}$ and ${\mathrm{\text{Li}}}_2{\mathrm{\text{S}}}_2$ on the surface of lithium anode to further elevate the capacity of battery. Meanwhile, the short-chain ${\mathrm{\text{Li}}}_2\mathrm{\text{S}}$ and ${\mathrm{\text{Li}}}_2{\mathrm{\text{S}}}_2$ in the solid electrolyte interphase (SEI) film on the surface of lithium metal can improve SEI’s mechanical properties and the interface compatibility between GPE and lithium metal. The multi-component synergistic effect of GPE provides the battery with superior cycle stability and excellent electrochemical performances. Bio-based GPE will exhibit a promising and alternative way for the practical application of lithium–sulfur batteries.

In this paper, ${\mathrm{\text{Cu(OH)}}}_2$ nanosheet arrays were directly grown in an upright manner on the surface of copper foam (CF) through a simple solvent reaction, followed by the successful reduction of ${\mathrm{\text{Cu(OH)}}}_2$ into ${\mathrm{\text{Cu}}}_2\mathrm{\text{O}}$ using hydrazine hydrate vapor, resulting in a binder-free ${\mathrm{\text{Cu}}}_2\mathrm{\text{O@CF}}$ array electrode. The in situ growth technique guarantees robust bonding between ${\mathrm{\text{Cu}}}_2\mathrm{\text{O}}$ and the conductive substrate, thereby enhancing electron transfer among various electrode components. Additionally, the vertically aligned array structures facilitate rapid penetration and transfer of the analyte, while also allowing for thorough exposure of the electroactive surfaces to the electrolyte. When utilized as an adhesive-free biosensor, the obtained ${\mathrm{\text{Cu}}}_2\mathrm{\text{O@CF}}$ array electrode exhibited sensitive catalytic oxidation activity toward acetaminophen (AP), providing a wide linear range of 2–200 $\mu$M and a low detection limit of 0.6 $\mu$M for AP detection. Furthermore, the developed ${\mathrm{\text{Cu}}}_2\mathrm{\text{O@CF}}$ array electrode was successfully utilized to detect AP in medicine samples. With its simple fabrication method, broad linear range, low detection limit, and excellent stability, this electrode holds significant promise for the detection of AP in pharmaceuticals.