Zhenjun Fan

Inspired by the brick-and-mortar architecture of natural nacre and mussel-adhesion chemistry, a biomimetic synergistic strategy was proposed to fabricate multifunctional poly(butylene adipate-co-terephthalate) (PBAT) composite films with a nacre-like architecture. This strategy integrates hexagonal boron nitride (h-BN)@ZnO hybrid filler construction with polydopamine (PDA) and octadecylamine (ODA) regulation of the filler-matrix interface. In this design, ZnO nanoparticles acted as physical spacers to suppress h-BN aggregation, while the PDA-ODA bilayer strengthened the interfacial adhesion through chain entanglement and hydrogen bonding. With only 1 wt % modified filler, the composite film attained a tensile strength of 42.2 MPa, 29.5% higher than that with unmodified h-BN, while retaining an elongation at a break of 543%. The synergistic ultraviolet (UV) protective mechanism involving PDA and ZnO endowed the films with excellent aging resistance. After 144 h of accelerated aging, the tensile strength retention of the film containing 5 wt % filler was 78.5% higher than that of neat PBAT. Meanwhile, the water vapor barrier performance was improved by 20.8%, the UV-shielding efficiency increased by 91.1%, and the hydrophobicity and thermal conductivity were also markedly enhanced. The film containing 3 wt % filler extended the shelf life of high-moisture fruits to more than 7 days. Under soil-burial conditions, the film with 1 wt % filler exhibited a mass loss of over 50% after 120 days, substantially exceeding that of neat PBAT, indicating that this material can degrade rapidly when it is discarded in soil. This biomimetic strategy provides an effective route for expanding the application potential of PBAT-based films.

We realize a tunable narrowband and broadband coexisting absorber based on a simple step-shaped all-metal grating structure. The absorber presents an ultra-narrow absorption band of 1.5 nm and a relatively broad absorption band of 29.8 nm, both with nearly 100% absorption in the infrared region. The mechanism underlying the dual-band perfect absorption is the interaction between two diffraction coupled surface plasmon polariton (SPP) modes with one of them modulated by a cavity resonance. Influences of structure parameters on the absorption performance are numerically investigated. It is found that the positions of the two perfect absorption peaks can be easily tuned both independently and together by changing the structural parameters. In addition, the designed grating structure presents excellent sensing performance with sensitivity and figure of merit as high as 2,514 nm/RIU and 1,600 RIU⁻¹, respectively. The excellent sensing performance, flexible tenability and simple structure design endow this grating absorber with great potential in high-precision biochemical sensing applications.

In this work, a series of compounds in the CaO-CoO_x-ErO_y ternary oxide system were synthesized in air at 885 °C, using a high temperature solid-phase synthesis method. The phase boundary of each solid solution region in the CaO-CoO_x-ErO_y system was determined by X-ray powder diffraction techniques. The phase diagram of the CaO-CoO_x-ErO_y system at 885 °C includes three series of ternary oxide solid solutions: (Ca_3−xEr_x)Co₄O_9−z (0 ≤ x ≤ 0.9), (Ca_3−xEr_x)Co₂O_6−z (0 ≤ x ≤ 1.25), and (Er_1−xCa_x)CoO_3−z (0 ≤ x ≤ 0.33). Four three-phase regions and five solid solution tie-line regions were obtained. The structure of the perovskite solid solution (Ca_3−xEr_x)Co₂O_6−z has been analyzed by Rietveld refinements. With the increase of Er content, the cell parameters of (Ca_3−xEr_x)Co₂O_6−z exhibit a decreasing trend in a and b directions and an increasing trend in c direction. A brief comparison of the phase diagrams of the CaO-CoO_x-RO_y (R = La, Dy, and Er) systems in air at 885 °C is provided.

In this work, a series of compounds in the CaO-½Er2O3-CoOz ternary oxide system were synthesized in air at 885℃ using high temperature solid-phase synthesis method. Phase boundary of each solid solution region in the CaO-½Er2O3-CoOz system was determined by X-ray powder diffraction technique. The phase diagram of the CaO-½Er2O3-CoOz system at 885℃ includes three series of ternary oxide solid solutions : (Ca3-xErx)Co4O9-z (0≤x≤0.9), (Ca3-xErx)Co2O6-z (0≤x≤1.25) and (Er1-xCax)CoO3-z (0≤x≤0.33). Four three-phase regions and five solid solution tie-line regions were obtained. The structure of perovskite solid solution (Ca3-xErx)Co2O6-z has been analyzed by Rietveld refinements. With the increase of Er content, the cell parameters of (Ca3-xErx)Co2O6-z exhibit an decreasing trend in a and b directions and an increasing trend in c direction.

We realize a tunable narrowband and broadband coexisting absorber based on a simple step-shaped all-metal grating structure. The absorber presents an ultra-narrow absorption band of 1.5 nm and a relatively broad absorption band of 29.8 nm, both with nearly 100% absorption in the infrared region. The mechanism underlying the dual-band perfect absorption is the interaction between two diffraction coupled surface plasmon polariton (SPP) modes with one of them modulated by a cavity resonance. Influences of structure parameters on the absorption performance are numerically investigated. It is found that the positions of the two perfect absorption peaks can be easily tuned both independently and together by changing the structural parameters. In addition, the designed grating structure presents excellent sensing performance with sensitivity and figure of merit as high as 2514 nm/RIU and 1600RIU^-1, respectively. Such high sensing metrics arise from the poor field localization and the ultra-narrow absorption band enabled by the diffraction coupled SPP modes as well as the specially designed all-metal structure. The excellent sensing performance, flexible tenability and simple structure design endow this grating absorber with great potential in high-precision biochemical sensing applications.

In optoelectronic applications, all-Brominated inorganic perovskite CsPbBr₃ solar cells have received a great deal of attention because of their remarkable stability and simplicity of production. Most of the solvents used in CsPbBr₃ perovskite solar cells are toxic, which primarily hinders the commercialization of the products. In this review, we introduce the crystal structure and fundamental properties of CsPbBr₃ materials and the device structure of perovskite cells, summarize the research progress of green solvents for CsPbBr₃ PSCs in recent years from mono-green solvent systems to all-green solvent systems, and discuss the approaches to improving the PCE of CsPbBr₃ PSCs, intending to facilitate the sustainable development of CsPbBr₃ perovskite solar cells. Finally, we survey the future of green solvents in the area of CsPbBr₃ perovskite solar cells.

金属有机框架材料(MOFs)是一种有机配体桥接金属离子组成的新型无机-有机杂化多孔材料,它具有功能可调、稳定性好以及多孔性等特点, 受到人们的广泛关注.本文利用水热法制备了高质量的锌离子掺杂的钴基[(CH₃)₂NH₂]Co_1-xZn_x(HCOO₃)单晶样品 (x=0, 0.1, 0.2, 0.3, 0.4, 0.5). 单晶衍射、摇摆曲线、EDX的实验结果表明锌离子均匀掺杂进了钴基金属有机框架材料中, 没有出现局部团簇等现象. 低温场冷曲线和比热曲线的测量结果表明, 非磁锌离子的掺杂减弱了Co基MOFs材料中Co离子之间的长程反铁磁相互作用, 使得Co-MOF的反铁磁相变温度由纯钴的15 K变为14.2 K (x=0.1), 12.8 K (x=0.2). 通过对掺锌样品低温下的磁滞回线的细致研究, 我们发现, 掺锌样品 相对于纯钴样品在低温下具有更大的磁滞损耗和矫顽场. 相比于纯钴样品450 Oe的矫顽场, 掺锌样品的矫顽场最高达到3600 Oe, 并且磁滞面积也为纯钴样品的3倍以上. 另一方面, 我们在DMCo_0.9Zn_0.1F样品的磁滞回线上发现一系列台阶, 这一台阶现象随着温度升高而逐渐消失, 类似于单分子磁体的量子隧穿现象. 以往研究表明, 在这一类钙钛矿结构的金属有机骨架材料中, 存在长程磁相互作用和磁单离子行为的竞争. 我们认为非磁锌离子的掺杂减弱了Co离子之间的长程相互作用, 使得Co离子在低温下显示出量子隧穿引起的台阶效应.