Inorganic nanoparticles have demonstrated significant applications in biomedicine field, whose biomedical functions and physicochemical properties are greatly influenced by their size and morphology. However, it still remains challenging to achieve high batch-to-batch reproducibility in the synthesis of inorganic nanoparticles with traditional batch synthesis methods. Meanwhile, microfluidic technology offers an advanced strategy that provides high controllability and repeatability for the synthesis of inorganic nanoparticles. Additionally, it facilitates rapid mass and heat transfer, while offering the advantages of small reaction volumes and low energy consumption, rendering it an ideal approach for the synthesis of inorganic nano-biomaterials. This article reviews the research and application progress of microfluidic technology in preparation of inorganic nano-biomaterials. Firstly, flow regimes and principles of mixing in the microfluidic devices are introduced. Subsequently, structural features and fluid mixing efficiency of five widely studied and applied microfluidic devices are presented. Importantly, applications of these microfluidic devices in synthesis and surface modification of inorganic nanoparticles are comprehensively summarized. Finally, this article briefly outlines challenges and potential opportunities for future developments in microfluidic-based synthesis and application of inorganic nano-biomaterials.

Compared with traditional lithium-ion batteries, sodium-ion batteries are an ideal alternative due to their cost advantages and sustainable resource supply. At present, the cathode materials for sodium-ion batteries mainly include transition metal oxides, polyanionic compounds and Prussian blue analogues. However, irreversible phase conversion, Jahn-Teller effect and interface instability of cathode materials seriously affect the cycling stability of sodium-ion batteries. In this paper, the research progress and industrialization process of strategies for improving cyclic stability of cathode materials for sodium-ion batteries are systematically introduced. Firstly, the structure as well as advantages and disadvantages of cathode materials is analyzed in detail, and the structural stability, cost and cycling performance are compared. Secondly, the latest research progress of structure optimization and chemical element doping strategies in improving the cycling stability of cathode materials is elaborated in detail, and the interaction between structural stability, electronic conductivity, ion intercalation/deintercalation of cathode materials and electrochemical performance is revealed. Then, the development process and industrialization progress of sodium-ion batteries are summarized. Finally, the significant problems that still need to be addressed for cathode materials and systems for sodium-ion batteries are sorted out and their future developments are prospected, aiming to propel the steady and healthy development of sodium-ion battery industry.

PrBaFe₂O_5+δ (PBF) is one of the most promising cathode materials for intermediate-temperature solid oxide fuel cell (IT-SOFC). Although PBF possesses similar area specific resistance (ASR) to that of Co-based cathode materials, electronic conductivity of PBF is an order of magnitude lower. Up to now, various doping strategies have been reported to enhance the electrochemical performance of this material, but still leaving it an open issue. In this study, PBF and Pr_1+xBa_1−xFe₂O_5+δ (PBF_x, x=0.01, 0.02, and 0.04) materials were synthesized by replacing Ba in PBF with excessive Pr using a Sol-Gel method, and their electrochemical performances as IT-SOFC cathodes were evaluated. For x=0.01, excessive Pr enters the lattice interstitials of PBF. For x≥0.02, 0.01 (in molar) excessive Pr occupies interstitial sites, while the rest replaces Ba in PBF. Over the temperature range of 650-800 ℃, excessive Pr promotes the conductivity of PBF, and PBF_0.01 exhibits the highest conductivity of 109.21 S•cm^-1, improving by 76%, which is attributed to the reduction in electronic transport path length. Furthermore, the excessive Pr contributes to lattice stress and dislocation density, reducing oxygen reduction reaction (ORR) activity and slightly increasing ASR of the cathode. Compared to PBF device, the peak power density of the Ni-SDC|SDC|PBF_0.01 (SDC: Sm_0.2Ce_0.8O_2-δ) single cell increased by approximately 49%, indicating that excessive Pr can significantly improve the electrochemical performance of cathode materials.

In recent years, Sb₂(S,Se)₃ has been considered a promising photovoltaic material due to its excellent photovoltaic properties. However, the highest reported photoelectric conversion efficiency (PCE) of Sb₂(S,Se)₃ solar cells still lags far behind its theoretical PCE limit, partly due to severe carrier recombination in Sb₂(S,Se)₃ films. In this study, a process additive, formamidinesulfinic acid (FSA), was introduced into the precursor solution of Sb₂(S,Se)₃ by hydrothermal deposition method. The additive FSA not only optimizes (211) and (221) orientations as well as Se/S atomic ratio of Sb₂(S,Se)₃ films, but also reduces Sb₂O₃ content of carrier recombination center in the films. The dark saturation current density (J₀) and recombination resistance (R_rec) values of the solar cell with FSA are 1.10×10⁻⁵ mA·cm⁻² and 3147 Ω·cm⁻², respectively, which are significantly better than those of reference device (5.17×10⁻⁵ mA·cm⁻² and 974.3 Ω·cm⁻²), indicating that the carrier recombination loss of Sb₂(S,Se)₃ solar cell is restricted. Under AM 1.5G, the mean values of open circuit voltage (V_OC), short circuit current density (J_SC), fill factor (FF), and PCE for the solar cell with FSA are 0.69 V, 18.46 mA·cm⁻², 63.60%, and 8.04%, respectively, showing significant improvement compared to reference device (0.67 V, 17.82 mA cm⁻², 62.27%, and 7.70%). The best device contributes the highest PCE of 8.21%, and this unpackaged device maintains 82.1% of its initial efficiency after a 120 d aging test in air.

Direct ethanol fuel cells (DEFC) have garnered significant attention due to their high energy conversion efficiency, low noise levels, and environmental friendliness. However, these fuel cells still face challenges such as high catalyst costs, poor stability, and low catalytic activity. In this study, graphene oxide (GO) was utilized as support, glycol as reducing agent, and hexahydrate chloroplatinic acid as precursor to introduce non-noble metal iron (Fe). By adjusting the molar ratio of Pt to Fe, a series of PtFeₓ/GO (x=1/6, 1/5, 1/4, 1/3, 1/2, 1) binary alloy catalysts were synthesized using microwave-assisted heating, and nanocrystals were in situ loaded on GO support. Fe with small atomic radii was incorporated into the lattice of Pt, resulting in reduction in spacing between adjacent atoms and lattice contraction, forming Pt-Fe alloy. Electrochemical performance tests demonstrated that the catalyst specifically at x=1/3 exhibited optimal catalytic activity with an electrocatalytic active area of 69.84 m²/g, an oxidation peak current density of 858.42 A/g, and a smaller Tafel slope. Its 1100 s steady stable current was 194.80 A/g, with CO oxidation peak potential of 0.554 V, activation energy of 18.37 kJ/mol, and current density retention rate of 80.48% after 800 cycles, all surpassing the performance of commercial Pt/C(JM). This study shows that incorporating the less expensive Fe can significantly enhance the catalytic activity and stability of Pt-based catalysts, providing important theoretical foundations for the design and potential applications of Pt-based catalyst materials.

Improper disposal of antibiotics poses significant risks to the aquatic environment. Development of efficient adsorbents for removal of antibiotics in environment is currently an important approach to address this issue. In this study, a series of zeolitic imidazolate framework (ZIF-67) materials with different morphologies were synthesized by adjusting the solvent composition during the synthesis process to investigate their adsorption properties for chlortetracycline hydrochloride (CTC). The results indicate that as the volume ratio of methanol to water decreases, the synthesized ZIF-67 transforms from a rhombic dodecahedral structure to a stacked hexagonal platelet structure which is more favorable for the adsorption of CTC. Based on a detailed investigation of the effects of temperature, solution pH, concentration, and types of impurity ions on the adsorption performance of CTC by ZIF-67 with a stacked hexagonal platelet structure (denoted as ZIF-67-3), the kinetics of the adsorption process indicate that the adsorption process follows both pseudo-second-order kinetic model and Langmuir model. Moreover, ZIF-67-3 (at a dosage of 100 mg·L^-¹) achieved a removal rate of over 90% for CTC (with an initial concentration of 30 mg·L^-1) within 20 min, and the maximum CTC adsorption capacity of ZIF-67-3 could reach 1206.58 mg·g⁻¹ under neutral conditions. Since ZIF-67-3 primarily adsorbs CTC through interactions such as π-π/π-cation interaction and hydrogen/coordination bonds, belonging to a monolayer chemical adsorption mechanism, ZIF-67-3 facilitates full exposure of active adsorption sites, thus exhibiting superior CTC adsorption performance. In summary, this study reveals the influence of solvent composition during synthesis on the morphology and structure of ZIF-67, elucidates the adsorption mechanism of ZIF-67-3 adsorbent for CTC, and provides theoretical support for the practical application of ZIF-67 in removal of antibiotic pollution.

As visible light photocatalysts, narrow bandgap semiconductors can effectively convert solar energy to chemical energy, exhibiting potential applications in alleviating energy shortage and environmental pollution. Cu₂O/Cu hollow spherical heterojunction photocatalysts were prepared by one-pot solvothermal method without any template using CuCl₂·H₂O as precursor, H₃NO·HCl and NaBH₄ as reducing agents. Morphologies, crystal structures, composition, specific surface areas, and optical properties of the products were analyzed. Addition of NaBH₄ gradually changes the morphology of Cu₂O/Cu from hollow truncated octahedra to hollow nanospheres. Thickness of Cu layer on surface of Cu₂O can be easily controlled by tuning amount of NaBH₄. Direct reduction of Cu₂O by NaBH₄ leads to intimate contact between Cu₂O and Cu interfaces, which is favorable for carrier separation and transport. Meanwhile, surface plasmon resonance effect of Cu promotes the absorption capability of Cu₂O/Cu to visible light, thus the prepared hollow sphere Cu₂O/Cu particles exhibit a higher photodegradation capability for methyl orange (MO) and colorless enrofloxacin (ENR). Catalytic performance of Cu₂O/Cu is very stable, with no significant change in its photocatalytic efficiency for MO after five recycles. Free-radical removal experiments indicate that ∙O₂^- and holes were dominant species during the MO degradation. Higher photodegradation capability of Cu₂O/Cu for MO is attributed to synergistic effect of Cu₂O and Cu. This study provides a promising strategy for preparation of heterojunction photocatalysts.

Fine-diameter continuous SiC fibers are considered one of the most effective reinforcing fibers for advanced ceramic matrix composites, possessing significant application potential in aerospace and nuclear industries. Among them, near-stoichiometric SiC fibers characterized by a highly crystalline microstructure have garnered considerable attention due to their exceptional high-temperature resistance. However, influence of high-temperature sintering conditions on composition and microstructure of the fibers is still unclear. Here, influences of different sintering temperatures and durations on decomposition of the SiC_xO_y phase, grain growth and densification of the fibers were systematically investigated. It was found that decomposition of SiC_xO_y and densification of fibers occur progressively from surface to core. Notably, a specific sintering temperature of 1800 ℃ was identified as optimal, wherein growth of β-SiC grains effectively compensated for the pore defects resulting from the decomposition of SiC_xO_y phase, thereby achieving fiber densification. Conversely, excessively high sintering temperature might result in decomposition of β-SiC grains. Although extending sintering duration facilitated removal of residual oxygen within the fibers, it could cause accumulation of graphite phases at β-SiC grain boundaries, leading to an increase in pore defects within the fiber core. Finally, near-stoichiometric SiC fibers with highly crystalline microstructure were successfully fabricated through optimization of sintering conditions, possessing a composition of SiC_1.04O_0.02Al_<0.01. The β-SiC grains within the fibers were uniformly distributed with sizes ranging from 100 to 200 nm. The fibers exhibited a tensile strength of 1.88 GPa and a Young’s modulus of 373 GPa, accompanied by a high density of 3.1 g/cm³. The findings of this research provide a robust foundation for further improving comprehensive properties of SiC fibers.

Light-weight, heat-insulating and high-temperature resistant materials are essential for safety of astronauts and precision equipments. Nanocellulose (CNFs), with high specific surface area, low thermal expansion coefficient and high strength, has application prospects in preparation of light-weight and thermal insulation aviation materials. However, brittleness and high flammability of CNFs limit their widespread use in high-temperature fields. In order to improve the high temperature resistance of CNFs, [PMo₁₂O₄₀]^3- intercalated ZnAl-PMo₁₂O₄₀-LDHs (PMo-LDHs, LDHs: layered double hydroxides) were successfully synthesized by co-precipitation and ion-exchange methods. Then the PMo-LDHs+BA/CNFs aerogel was prepared by combining ZnAl-PMo₁₂O₄₀-LDHs with boric acid (BA) to formulate CNFs composites. When the mass fractions of PMo-LDHs and BA are 62.5% and 2.0% of CNFs, density and thermal conductivity of 62.5PMo-LDHs+BA/CNFs aerogel are 16.28 kg·m^-3 and 0.044 W/(m·K), respectively. Thermal insulation back-fire temperature experiments indicate that t₂₅₀ (time required to reach a thermal insulation temperature of 250 ℃) of 62.5PMo-LDHs+BA/CNFs aerogel is 2022.8 s, which is 867.8 s longer than that of pure CNFs aerogel. R₂₅₀ (heating rate when an insulation temperature reaches 250 ℃) is only 0.124 ℃·s^-1, which is 57.4% of R₂₅₀ for pure CNFs aerogel, demonstrating an exceptionally excellent thermal insulation effect. Combustion experiments reveal that the pure CNFs aerogel undergoes complete combustion within 15 s, whereas 62.5PMo-LDHs+BA/CNFs aerogel does not ignite within 81 s and exhibits no obvious shrinkage or deformation. Morphological observation of combustion residues indicates that a dense and uniform continuous carbon layer is formed on the surface of the aerogel due to the decomposition of PMo-LDHs, which significantly improves fire resistance of the CNFs aerogel.

Rare earth silicate environmental barrier coatings (EBCs) are important materials that can be applied to hot sections for the new generation of high thrust-to-weight ratio aero engines. However, oxidation and cracking of the silicon bond layer are significant factors leading to failure during service. Modifying the silicon bond layer has become an important method to extend EBCs’ service life. In this work, Yb₂O₃ was doped in the silicon bond layer to mitigate cracking under high-temperature water vapor conditions, as well as to improve its corrosion resistance. Five kinds of EBC systems (Si-Yb₂O₃)/Yb₂Si₂O₇/Yb₂SiO₅ with different Yb₂O₃ doping (0, 5%, 10%, 15%, 20%, in volume) were prepared on SiC substrates using vacuum plasma spraying technology. Their water-oxygen corrosion behavior was studied, and mechanisms at 1350 ℃ beneath their behavior were revealed. The results indicated that doping an appropriate amount (5%) of Yb₂O₃ into silicon effectively facilitates the reaction with SiO₂ and its subsequent consumption during high-temperature water vapor corrosion. This process reduces the stress variations associated with SiO₂ phase transition (β → α) and inhibits formation of longitudinal cracks in mixed thermal growth oxide (mTGO) layer, thus enhancing structural stability. Furthermore, the reaction product of Yb₂Si₂O₇ exhibits a suitable coefficient of thermal expansion (CTE) and chemical compatibility. Notably, increasing Yb₂O₃ content results in formation of interconnected "skeleton" structure within the bond layer, which may provide a direct pathway for oxidizing substances to permeate into the interior of coating, thereby facilitating corrosion process within the bond layer, and ultimately diminishing the water vapor corrosion resistance of EBC systems.

As an essential candidate for environment-friendly luminescent quantum dots (QDs), CuInS-based QDs have attracted more attention in recent years. However, several drawbacks still hamper their industrial applications, such as lower photoluminescence quantum yield (PLQY), complex synthetic pathways, uncontrollable emission spectra, and insufficient photostability. In this study, CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra. Then their ensemble spectroscopic properties during nucleation formation, alloying, and ZnS shell growth processes were systematically investigated. PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In, Zn²⁺ doping and ZnS shell growth. In particular, CuInZnS@ZnS QDs possess a significantly long emission lifetime (up to 750 ns), high PLQY (up to 85%), and excellent crystallinity. Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model. By controlling the stoichiometric ratio of Cu/In, two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects. Therefore, this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.

Owing to outstanding hydrophilicity and ionic interaction, layered double hydroxides (LDHs) have emerged as a promising carrier for high performance catalysts. However, the synthesis of new specialized catalytic LDHs for degradation of antibiotics still faces some challenges. In this study, a CoFe₂O₄/MgAl-LDH composite catalyst was synthesized using a hydrothermal coprecipitation method. Comprehensive characterization reveals that the surface of MgAl-LDH is covered with nanometer CoFe₂O₄ particles. The specific surface area of CoFe₂O₄/MgAl-LDH is 82.84 m²·g^-1, which is 2.34 times that of CoFe₂O₄. CoFe₂O₄/MgAl-LDH has a saturation magnetic strength of 22.24 A·m²·kg^-1 facilitating efficient solid-liquid separation. The composite catalyst was employed to activate peroxymonosulfate (PMS) for the efficient degradation of tetracycline hydrochloride (TCH). It is found that the catalytic performance of CoFe₂O₄/MgAl-LDH significantly exceeds that of CoFe₂O₄. The maximum TCH removal reaches 98.2% under the optimal conditions ([TCH] = 25 mg/L, [PMS] = 1.5 mmol/L, CoFe₂O₄/MgAl-LDH = 0.20 g/L, pH 7, and T = 25 ℃). Coexisting ions in the solution, such as SO₄²⁻, Cl⁻, H₂PO₄⁻, and CO₃²⁻, have a negligible effect on catalytic performance. Cyclic tests demonstrate that the catalytic performance of CoFe₂O₄/MgAl-LDH remains 67.2% after five cycles. Mechanism investigations suggest that O₂^•−and ¹O₂ produced by CoFe₂O₄/MgAl-LDH play a critical role in the catalytic degradation.