Bismuth-activated,narrow-band,cyan garnet phosphor Ca3Y2Ge3O12:Bi3+ for near-ultraviolet-pumped white LED application

Herein, a novel Bi³⁺-activated Ca₃Y₂Ge₃O₁₂ (CYGO) narrow-band cyan-emitting phosphor was synthesized. It can be excited from 320–420 nm, and the strongest excitation peak is located at 370 nm, which is suitable for current near-ultraviolet (NUV) chips perfectly. The full width at half maximum is at 52 nm. By analyzing the crystal structure of the sample, we infer that the Bi³⁺ ions replace the Y³⁺ site to form a highly symmetrical BiO₆ octahedron. The time-resolved photoluminescence (TRPL) spectra of CYGO: Bi³⁺ reveal that the only a single emission center exists in the host lattice. A warm white light–emitting diode (WLED) device with a low correlated color temperature (3148 K) and a high color rendering index (90.2) was fabricated by using the as-prepared sample, and the significant thermal stability of CYGO: Bi³⁺ guarantees its potential application in WLEDs. It is verified that the structure with only one crystallographic Y site for Bi³⁺ dopant occupation and highly symmetrical and dense structure is conducive to realize narrow-band emission, which will provide experience for researchers to explore more Bi³⁺-activated phosphors used for high-end lighting.     

Preparation of ultrafine Sb_2O_5 composite powder

ＰＲＥＰＡＲＡＴＩＯＮＯＦＵＬＴＲＡＦＩＮＥＳｂ＿２Ｏ＿３－Ｓｂ＿２Ｏ＿５ＣＯＭＰＯＳＩＴＥＰＯＷＤＥＲＤｕａｎ，Ｘｕｅｃｈｅｎ；Ｚｈａｏ，Ｔｉａｎｃｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＮｏｎｆｅｒｅｒｒｏｕｓＭｅｔａｌｌｕｒｇｙ．ＣｅｎｔｒａｌＳｏｕｔ...     

低温烧结SrBi4Ti4O15／Ag复合材料的制备及其介电特性

摘要：采用固相烧结工艺制备了SrBi4Ti4O15(SBTi)／Ag铁电复合材料，通过X射线衍射、光学金相显微镜和扫描电子显微镜对材料的组成和微观结构进行了研究，并测量样品的介电温度谱。结果表明：复合材料是由SBTi和Ag两相组成。微量金属Ag的加入使SBTi铁电陶瓷的烧结温度从1120℃降低到950℃以下：可以适当提高铁电陶瓷从室温到200℃的介电常数，但对材料的介电损耗影响很小。同时Ag的加入压抑了介电温度曲线上的介电常数的Curie峰。     

天然石墨／锑复合材料作为锂离子电池负极材料嵌／放锂性能研究

研究了用简单混杂和球磨方法制备的天然石墨／锑复合材料作为锂离子电池负极材料的嵌／放锂性能以及循环过程中嵌／放锂容量衰减机理。复合材料中的锑以独立的可逆嵌／放锂反应参与吸／放锂过程并显著提高复合材料的嵌／放锂容量。较大颗粒的锑在嵌／放锂过程中体积剧变导致颗粒破碎、电接触恶化而渐渐失去嵌／放锂活性，因此由简单混杂所获得石墨／锑复合材料在循环过程中容量逐渐降低；采用球磨方法在天然石墨颗粒表面形成弥散分布的小颗粒锑则能获得具有较高可逆容量和较好的循环稳定性的石墨／锑复合锂离子电池负极材料。     

湿法锑白的晶型转变

研究了湿法锑白的白度和光敏性。通过真空干燥试验研究，对样品进次了Ｘ射线衍射定量分析，首次发现真空干燥可以使湿法锑白发生晶型转变，由斜方晶体转变为立方晶体。在适宜条件下，其转变率可达９９．６％。转变为立方晶的锑白白度高且见光稳定，光敏性消失。     

纳米硫化铋-锌复合镀膜的制备及其抗菌性能研究

目的将锌镀层与具有光催化抗菌性能的纳米粒子复合,实现对锌镀层的改性,成功制备一种具有光催化抗菌性能的功能性复合镀层。方法通过向弱酸性硫酸盐锌镀液中加入梯度浓度具有可见光催化杀菌性能的硫化铋纳米粒子,在20#碳钢表面利用恒电流法一步成功制备了系列硫化铋-锌复合镀膜。利用电化学工作站监测了沉积过程中的沉积电位,分别记录沉积前和沉积后的样品质量并测量沉积面积,通过计算,确定了沉积过程的电流效率。通过扫描电子显微镜(SEM)、X-射线晶体衍射仪(XRD)及电子能谱仪(EDS)对镀层进行了形貌及成分分析,采用大肠杆菌作为代表性的细菌,检测了复合镀膜的抗菌性能。结果与纯锌镀膜相比,硫化铋的加入显著促进了(100)晶相的晶体生长,而抑制了(102)晶相的晶体生长,使镀膜形貌由标准六方晶系变为块状晶体;硫化铋的加入使沉积电位变得更正,且随硫化铋添加量的增加,变正增幅变大;硫化铋的加入使电沉积过程的电流效率与纯锌镀膜的电流效率相比增大了5%左右,但硫化铋的添加量对电流效率的影响不大;硫化铋-锌复合镀膜在可见光下对大肠杆菌具有良好的抗杀性能,且硫化铋的复合量越高,抗菌效果越好。结论通过笔者提出的电沉积方法,硫化铋可成功复合到了锌镀膜中,从而使硫化铋-锌复合镀膜获得了良好的抗菌性能,最终发现当镀液中硫化铋质量浓度为2 g/L时,硫化铋在锌镀层中的复合量最高,抗菌性能最好。     

Hydrated Bi-Ti-Bimetal Ethylene Glycol: A New High-Capacity and Stable Anode Material for Potassium-Ion Batteries

Potassium-ion batteries have emerged not only as low-cost alternatives to lithium-ion batteries, but also as high-voltage energy storage systems. However, their development is still encumbered by the scarcity of high-performance electrode materials that can endure successive potassium-ion uptake. Herein, a hydrated Bi-Ti bimetallic ethylene glycol (H-Bi-Ti-EG) compound is reported as a new high-capacity and stable anode material for potassium storage. H-Bi-Ti-EG possesses a long-range disordered layered framework, which helps to facilitate electrolyte ingress into the entire Bi nanoparticles. A suite of spectroscopic analyses reveals the in situ formation Bi nanoparticles within the organic polymer matrix, which can alleviate stresses caused by the huge volume expansion/contraction during deep cycles, thereby maintaining the superior structural integrity of H-Bi-Ti-EG organic anode. As expected, H-Bi-Ti-EG anode exhibits a high capacity and superior long-term cycling stability. Importantly for potassium storage, it can be cycled at current densities of 0.1, 0.5, 1, and 2 Ag⁻¹ for 800, 700, 1000, and even 6000 cycles, retaining charging capacities of 361, 206, 185, and 85.8 mAh g⁻¹, respectively. The scalable synthetic method along with the outstanding electrochemical performance of hydrated Bi-Ti-EG, which is superior to other reported Bi-based anode materials, places it as a promising anode material for high-performance potassium storage.     

Intercalative Motifs-Induced Space Confinement and Bonding Covalency Enhancement Enable Ultrafast and Large Sodium Storage

Alloying-type metal sulfides with high theoretical capacities are promising anodes for sodium-ion batteries, but suffer from sluggish sodiation kinetics and huge volume expansion. Introducing intercalative motifs into alloying-type metal sulfides is an efficient strategy to solve the above issues. Herein, robust intercalative In S motifs are grafted to high-capacity layered Bi₂S₃ to form a cation-disordered (BiIn)₂S₃, synergistically realizing high-rate and large-capacity sodium storage. The In S motif with strong bonding serves as a space-confinement unit to buffer the volume expansion, maintaining superior structural stability. Moreover, the grafted high-metallicity Indium increases the bonding covalency of Bi S, realizing controllable reconstruction of Bi S bond during cycling to effectively prevent the migration and aggregation of atomic Bi. The novel (BiIn)₂S₃ anode delivers a high capacity of 537 mAh g⁻¹ at 0.4 C and a superior high-rate stability of 247 mAh g⁻¹ at 40 C over 10000 cycles. Further in situ and ex situ characterizations reveal the in-depth reaction mechanism and the breakage and formation of reversible Bi S bonds. The proposed space confinement and bonding covalency enhancement strategy via grafting intercalative motifs can be conducive to developing novel high-rate and large-capacity anodes.     

Room-Temperature Magnetic Skyrmions and Large Topological Hall Effect in Chromium Telluride Engineered by Self-Intercalation

Room-temperature magnetic skyrmion materials exhibiting robust topological Hall effect (THE) are crucial for novel nano-spintronic devices. However, such skyrmion-hosting materials are rare in nature. In this study, a self-intercalated transition metal dichalcogenide Cr_1+xTe₂ with a layered crystal structure that hosts room-temperature skyrmions and exhibits large THE is reported. By tuning the self-intercalate concentration, a monotonic control of Curie temperature from 169 to 333 K and a magnetic anisotropy transition from out-of-plane to the in-plane configuration are achieved. Based on the intercalation engineering, room-temperature skyrmions are successfully created in Cr_1.53Te₂ with a Curie temperature of 295 K and a relatively weak perpendicular magnetic anisotropy. Remarkably, a skyrmion-induced topological Hall resistivity as large as ≈106 nΩ cm is observed at 290 K. Moreover, a sign reversal of THE is also found at low temperatures, which can be ascribed to other topological spin textures having an opposite topological charge to that of the skyrmions. Therefore, chromium telluride can be a new paradigm of the skyrmion material family with promising prospects for future device applications.     

卤-锑协同阻燃机理研究进展

详细论述了卤－锑阻燃协同体系的阻燃机同机理，以及卤－锑阻燃机理方面的研究新进展。