Germanium-Carbdiyne: A 3D Well-Defined sp-Hybridized Carbon-Based Material with Superhigh Li Storage Property

Carbyne delivers various excellent properties for the existence of the larger number of sp-hybridized carbon atoms.Here,a 3D well-defined porous carbon material germanium-carbdiyne(Ge-CDY)which is comprised of only sp-hybridized carbon atoms bridging by Ge atoms has been developed and investigated.The unique diamond-like structure constructed by linear butadiyne bonds and sp 3-hybridized Ge atoms ensures the stability of Ge-CDY.The large percentage of conjugated alkyne bonds composed of sp-C guarantees the good conductivity and the low band gap,which were further confirmed experimentally and theoretically,endowing Ge-CDY with the potential in electrochemical applications.The well-defined 3D carbon skeleton of Ge-CDY provides abundant uniform nanopores,which is suitable for metal ions storage and diffusion.Further half-cell evaluation also demonstrated Ge-CDY exhibited an excellent performance in lithium storage.All those indicating sp-hybridized carbon-based materials can exhibit great potential to possess excellent properties and be applied in the field of energy,electronic,and so on.

Ge nanoparticles uniformly immobilized on 3D interconnected porous graphene frameworks as anodes for high-performance lithium-ion batteries

Germanium(Ge), an alloy-type anode material for lithium-ion batteries(LIBs), possesses many advantages such as high theoretical capacity and decent electrical conductivity. Nevertheless, its application is restricted by tremendous volume variation and tardy reaction kinetic during discharge/charge process.In this paper, the Ge/3DPG composites with Ge nanoparticles uniformly dispersed in 3D interconnected porous graphene(3DPG) skeleton are successfully prepared using a template-assisted in-situ reduction method. The unique 3D interconnected porous graphene can not only enhance the electronic conductivity and reaction kinetics of the materials, but also provide sufficient buffer space to effectively mitigate the volume expansion during cycling and strengthen the structural integrity. Moreover, the small-sized Ge nanoparticles in close conjunction with the 3D graphene can boost the surface-controlled reaction of the electrode, which contributes to a fast charge–discharge rate capability. The Ge/3DPG composite with optimized Ge/graphene mass ratio delivers high reversible specific capacity(1102 mAh g^(-1) after 100 cycles at 0.2 C), outstanding rate capability(494 mAh g^(-1) at 5 C), and admirable cycling stability(85.3% of capacity retention after 250 cycles at 0.5 C). This work provides a significant inspiration for the design and fabrication of advanced Ge-based anode materials for next-generation highperformance LIBs.

Boosting High-Rate Zinc-Storage Performance by the Rational Design of Mn_(2)O_(3) Nanoporous Architecture Cathode

Manganese oxides are regarded as one of the most promising cathode materials in rechargeable aqueous Zn-ion batteries(ZIBs)because of the low price and high security.However,the practical application of Mn2O3 in ZIBs is still plagued by the low specific capacity and poor rate capability.Herein,highly crystalline Mn2O3 materials with interconnected mesostructures and controllable pore sizes are obtained via a ligand-assisted self-assembly process and used as high-performance electrode materials for reversible aqueous ZIBs.The coordination degree between Mn2+and citric acid ligand plays a crucial role in the formation of the mesostructure,and the pore sizes can be easily tuned from 3.2 to 7.3 nm.Ascribed to the unique feature of nanoporous architectures,excellent zinc-storage performance can be achieved in ZIBs during charge/discharge processes.The Mn2O3 electrode exhibits high reversible capacity(233 mAh g−1 at 0.3 A g−1),superior rate capability(162 mAh g−1 retains at 3.08 A g−1)and remarkable cycling durability over 3000 cycles at a high current rate of 3.08 A g−1.Moreover,the corresponding electrode reaction mechanism is studied in depth according to a series of analytical methods.These results suggest that rational design of the nanoporous architecture for electrode materials can effectively improve the battery performance.

Porous 3D carbon-based materials:An emerging platform for efficient hydrogen production

Due to their unique properties and uninterrupted breakthrough in a myriad of clean energy-related applications,carbon-based materials have received great interest.However,the low selectivity and poor conductivity are two primary difficulties of traditional carbon-based materials(zero-dimensional(0D)/one-dimensional(1D)/two-dimensional(2D)),enerating inefficient hydrogen production and impeding the future commercialization of carbon-based materials.To improve hydrogen production,attempts are made to enlarge the surface area of porous three-dimensional(3D)carbon-based materials,achieve uniform interconnected porous channels,and enhance their stability,especially under extreme conditions.In this review,the structural advantages and performance improvements of porous carbon nanotubes(CNTs),g-C_(3)N_(4),covalent organic frameworks(COFs),metal-organic frameworks(MOFs),MXenes,and biomass-derived carbon-based materials are firstly summarized,followed by discussing the mechanisms involved and assessing the performance of the main hydrogen production methods.These include,for example,photo/electrocatalytic hydrogen production,release from methanolysis of sodium borohydride,methane decomposition,and pyrolysis-gasification.The role that the active sites of porous carbon-based materials play in promoting charge transport,and enhancing electrical conductivity and stability,in a hydrogen production process is discussed.The current challenges and future directions are also discussed to provide guidelines for the development of next-generation high-efficiency hydrogen 3D porous carbon-based materials prospected.

Micro-sized and Nano-sized Fe_3O_4 Particles as Anode Materials for Lithium-ion Batteries

Micro-sized（1030.3±178.4 nm） and nano-sized（50.4±8.0 nm） Fe3O4 particles have been fabricated through hydrogen thermal reduction of α-Fe2O3 particles synthesized by means of a hydrothermal process.The morphology and microstructure of the micro-sized and the nano-sized Fe3O4 particles were characterized by X-ray diffraction,field-emission gun scanning electron microscopy,transmission electron microscopy and highresolution electron microscopy.The micro-sized Fe3O4 particles exhibit porous structure,while the nano-sized Fe3O4 particles are solid structure.Their electrochemical performance was also evaluated.The nano-sized solid Fe3O4 particles exhibit gradual capacity fading with initial discharge capacity of 1083.1 mAhg-1 and reversible capacity retention of 32.6% over 50 cycles.Interestingly,the micro-sized porous Fe3O4 particles display very stable capacity-cycling behavior,with initial discharge capacity of 887.5 mAhg-1 and charge capacity of 684.4 mAhg-1 at the 50th cycle.Therefore,77.1% of the reversible capacity can be maintained over 50 cycles.The micro-sized porous Fe3O4 particles with facile synthesis,good cycling performance and high capacity retention are promising candidate as anode materials for high energy-density lithium-ion batteries.

NaHCO_(3)-induced porous PbI_(2) enabling efficient and stable perovskite solar cells

Driven by their many unique features,perovskite solar cells(PSCs)have become one of the most promising candidates in the photovoltaic field.Two-step preparation of perovskite film is advantageous for its higher stability and reproducibility compared to the one-step method,which is more suitable for practical application.However,the incomplete conversion of the dense lead iodide(PbI_(2))layer during the sequential spin-coating of formamidinium/methylammonium(FA^(+)/MA^(+))organic amine salts severely affect the performance of PSCs.Herein,sodium bicarbonate(NaHCO_(3))is used to induce the formation of porous PbI_(2),which facilitates the penetration of the FA^(+)/MA^(+)ions and the formation of a perovskite film with high crystallinity and large grain microstructure.Meanwhile,the introduction of Na^(+)not only improves the energetic alignment of the PSC,but also increases the conductivity via p-doping.As a result,the optimized NaHCO_(3)-modified PSC achieves a champion power conversion efficiency of 24.0% with suppressed hysteresis.Moreover,the significant reduction in defect density and ion migration as well as a mild alkaline environment enhance the stability of device.The unencapsulated NaHCO_(3)-modified PSCs maintain over 90% of their original efficiency upon storage in ambient air(30%–40% relative humidity)for 2160 h.We have demonstrated an ingenious strategy for controlling the quality of perovskite and improving the performance of device by low-temperature foaming of simple inorganic molecules of NaHCO_(3).

Preparation and properties of ZrO_(2)-strengthened porous mullite insulation materials using Y_(2)O_(3) additive

ZrO_(2)-strengthened porous mullite insulation materials were prepared by foaming technology utilizing ZrSiO_(4) and Al_(2)O_(3) as primary materials and Y_(2)O_(3) as an additive.The effects of Y_(2)O_(3) contents on the phase composition,microstructure,mechanical properties,and heat conductivity of the porous mullite insulation materials were investigated.A suitable Y_(2)O_(3) content could promote phase transition of monoclinic ZrO_(2)(m-ZrO_(2))to tetragonal ZrO_(2)(t-ZrO_(2)),reduce pore size,and improve the strengths of as-prepared specimens.The cold crushing strength and bending strength of as-prepared specimens with a 119µm spherical pore size using 6 wt.%Y_(2)O_(3) were 35.2 and 13.0 MPa,respectively,with a heat conductivity being only 0.248 W/(m K).

Introduction of porous structure:A feasible and promising method for improving thermoelectric performance of Bi_2Te_3 based bulks

The porous p-type BiSbTebulks containing irregularly and randomly oriented pores were obtained by artificially controlling the relative density of sintered samples during resistance pressing sintering process. It is demonstrated that the thermoelectric performances are significantly affected by the porous structure, especially for the electrical and thermal conductivity due to the enhanced carrier scattering and phonon scattering. The increasing porosity resulted in the obvious decrease in electrical and thermal conductivity, and little change in Seebeck coefficients. It is encouraging that the reduction of thermal conductivity can compensate for the deterioration of electrical performance, leading to the enhancement in thermoelectric figure of merit(ZT). The maximum ZT value of 1.0 was obtained for the sample with a relative density of 90% at 333 K. Unfortunately, the increase in porosity also brought in obvious degradations in Vickers hardness from 51.71 to 27.74 HV. It is worth mentioning that although the Vickers hardness of the sample with a relative density of 90% decreased to 40.12 HV, it was still about twice as high as that of the zone melting sample(21.25 HV). To summarize, introducing pores structure into bulks properly not only enhances the ZT value of BiTebased alloys, but also reduces the use of raw materials and saves production cost.

Design and Construction of 3D Porous Na3V2(PO4)3/C as High Performance Cathode for Sodium Ion Batteries

An easy and delicate approach using cheap carbon source as conductive materials to construct 3D sequential porous structural Na3V2(PO4)3/C(NVP/C)with high performance for cathode materials of sodium ion battery is highly desired.In this paper,the NVP/C with 3D sequential porous structure is constructed by a delicate approach named as“cooking porridge”including evaporation and calcination stages.Especially,during evaporation,the viscosity of NVP/C precursor is optimized by controlling the adding quantity of citric acid,thus leading to a 3D sequential porous structure with a high specific surface area.Furthermore,the NVP/C with a 3D sequential porous structure enables the electrolyte to interior easily,providing more active sites for redox reaction and shortening the diffusion path of electron and sodium ion.Therefore,benefited from its unique structure,as cathode material of sodium ion batteries,the 3D sequential porous structural NVP/C exhibits high specific capacities(115.7,88.9 and 74.4 mA·h/g at current rates of 1,20 and 50 C,respectively)and excellent cycling stability(107.5 and 80.4 mA·h/g are remained at a current density of 1 C after 500 cycles and at a current density of 20 C after 2200 cycles,respectively).

Ammonia-assisted synthesis method for CoTiO_3 nanoporous matrix

The theory of an ＂ammonia fountain＂ was developed to synthesize a CoTiO3 nanoporous matrix using a modified co-precipitation method at the interface of the aqueous solution and the saturated NH3 atmosphere. On the basis of this theory, for the first time, a new assumption was expanded to show the regular （re）arrangement of metal cations near to the surface of the solution. The morphology of the CoTiO3 phase was observed using SEM. The result indicates the nano-narrow formation of CoTiO3 particles. The size of the particles was calculated at about 27 nm. From the XRD patterns, the formation of cobalt titanate nanoparticles was confirmed.

Polarized hydroxyapatite/BaTiO_(3) scaffolds with bio-inspired porous structure for enhanced bone penetration

The porous HA/BaTiO_(3)ceramics have the potential to exhibit superior capabilities to promote bone in-growth.However,there are few reports on in vivo studies.Here,we fabricated bio-inspired porous HA/BaTiO_(3)composites for bone repair via freeze-casting.These composites had a unique microstructure composed of the central canal and radically distributed lamellae,similar to the structure of nature cortical bone unite,the Haversian system.Polarized and non-polarized bio-inspired porous HA/BaTiO_(3)samples were implanted into the femoral condyle of the New Zealand rabbits.It was demonstrated that the polarization of the porous HA/BaTiO_(3)played a favorable part in bone regeneration.Moreover,the combination between the osteoconductivity of the microstructure and augmented osteogenic cell behavior induced by charges on surfaces of polarized porous HA/BaTiO_(3)facilitated bone penetration through the implants.The bio-inspired porous HA/BaTiO_(3)composites are demonstrated to be promising scaffolds for bone repair.

Preparation and Electrochemical Performance of Li[Ni1/3Co1/3Mn1/3]O2 Synthesized Using LizCO3 as Template

Porous structure Li[Ni1/3Co1/3Mn1/3]O2 has been synthesized via a facile carbonate co-precipitation method using Li2CO3 as template and lithium-source. The physical and electrochemical properties of the materials were examined by many characterizations including TGA, XRD, SEM, EDS, TEM, BET, CV, EIS and galvanostatic charge-discharge cycling. The results indicate that the as-synthesized materials by this novel method own a well-ordered layered structure a-NaFeO2 [space group： R-3m（166）], porous morphology, and an average primary particle size of about 150 nm. The porous material exhibits larger specific surface area and delivers a high initial capacity of 169.9 mAh·g^-1 at 0.1 C （1 C=180 mA·g ^-1） between 2.7 and 4.3 V, and 126.4, 115.7 mAh.g 1 are still respectively reached at high rate of 10 C and 20 C. After 100 charge-discharge cycles at 1 C, the capacity retention is 93.3%, indicating the excellent cycling stability.

水热合成和冷冻干燥相结合制备超轻三维多孔γ-MnOOH材料（英文）

超轻三维多孔金属氧化物材料在许多应用中起着重要作用,因此采用低成本的材料和简便的方法制备它们显得非常重要.本文以高锰酸钾、氯化锰和氢氧化钠为原料,结合水热合成法和冷冻干燥法首次制备出超低密度(<0.078 g cm^(-3))、形状可控和连续多孔的三维氢氧化氧锰(3D-γ-MnOOH).系统地研究了反应物添加量和水热反应时间对3D-γ-MnOOH合成过程的影响,得出制备3D-γ-MnOOH的最优工艺条件:NaOH/KMnO_4和MnCl_2/KMnO_4的摩尔比分别为5.0和3.5,水热温度和时间分别为180°C和10 h.由于γ-MnOOH具有低密度和充满空气的三维孔道结构,使其可以在水中漂浮4个月以上,并保持微结构不变.分析探讨了3D-γ-MnOOH的微结构形成机制和漂浮机理.超轻3D-γ-MnOOH的成功制备将促进其在吸油、储能、催化剂载体等领域的应用.