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Rechargeable lithium metal batteries (LMBs) have been regarded as the most promising next-generation high-energy-density storage devices. However, the uncontrolled dendrite growth and short lifespan hinder their practical application, especially at high current densities. Herein, we propose a mixed ion-electron conducting scaffold derived from a porous CoP film with high surface area and lithiophilic properties, which serves as a host material for dendrite free lithium deposition. The scaffold is in situ transformed from the porous CoP film made by a facile electrodeposition process. In liquid electrolytes, the scaffold can not only reduce the lithium nucleation barrier but also ensure a uniform lithium-ion distribution, thereby achieving uniform and smooth lithium deposition. As a result, the Li||Cu cell shows a high coulombic efficiency (CE) of 98.63% for lithium plating/stripping, and the full cell with the LiFePO4 (LFP) cathode (Li||LFP) shows highly stable cycling performance at high C-rates, showing the strength of high ionic/electronic conductivity for stable lithium metal batteries.

Janus graphene oxide (GO) usually refers to a unique two-dimensional material with asymmetric surface chemistries on opposite faces of the sheets. Herein, we propose a facile and efficient method to fabricate Janus-like GO (JGO) with a novel asymmetric structure along the faces of the sheets. Unlike the traditional post-synthesis of double-faced Janus GO based on pre-prepared GO, the novel JGO with a randomly distributed asymmetric oxidation structure along the sheet face can be achieved by a simple ultrasonic treatment on partially oxidized graphene. The asymmetric oxidation structure along the sheet face of our Janus GO was confirmed by confocal micro-Raman imaging and analysis of height profiles by atomic force microscopy. Due to the asymmetric oxidation structure, the as-prepared JGO has amphiphilic characteristics, with hydrophilicity on one side of the sheet and hydrophobicity on the other side, leading to an eyelash-like liquid crystal alignment at the oil/water interface. The perpendicular alignment rather than the parallel orientation behavior of GO liquid crystals at the oil/water interface further confirms the asymmetric structure of our JGO along the face graphene sheets. The simple approach and a new class of JGO proposed herein provide a new insight into understanding the asymmetric chemistry of graphene.

Nowadays, high performance and functional low-dimensional nanomaterials have been targeted in modern sustainable energy science for diverse potential applications. However, broad applications of emerging nanomaterials such as graphene and biomass nanofillers have suffered from low preparation efficiency, low quality of products, unstable dispersion in matrix. In this study, a 100% yield of low-oxidized graphene/nanocellulose hybrids (LGENC) was prepared by one-pot ball milling. Low-oxidized expanded graphite (LOEG) and microfibrillated cellulose (MFC) were used as precursors for fabricating LGENC by the co-exfoliation strategy. That is, exfoliation of LOEG, nanofibrillation of MFC and their hybridization were simultaneously realized under the shear and collision of balls milling. The concentration of LGENC suspension can be concentrated to 50 mg/mL, which has great potential for 3D printing. A series of characterization identified the hybridization of low-oxidized graphene (LGE) and nanocellulose via hydrophobic and hydrogen bond interaction, and confirmed that the LGE has fewer oxygen functional groups and more complete structure than graphene oxide. Benefiting from the intact structure, the conductivity of LGENC can reach up to ~5800 S/m. In addition, the as-prepared LGENC showed significant potential in reinforcing rubber latex. In general, this study proposes a high-efficiency preparation method for graphene/cellulose hybrid materials with extraordinary properties.

Bio-inspired citrate-hydroxyapatite (HAP) nanoparticles doped with zinc ions were prepared from mussel shells via a rapid method of ultrasonication and microwave irradiation. It was found that zinc ions can interact with citrate ions in the crystallization process of HAP. The growth of nanocrystals in citrate solution was slower than that in HCl solution. The addition of zinc ions reduced the residue of citrate in the products and increased the crystallinity of HAP. Furthermore, mineral platelets with the length of 29 ± 7 nm and the thickness of 3–5 nm were obtained for Zn/(Zn+Ca) = 5 mol%, which displayed similar morphology with HAP platelets in bone. Moreover, the obtained HAP nanoparticles are promising for use as bone graft materials in biomedical applications.

In this study, a biomimetic method was used to prepare hydroxyapatite (HAP) and zinc substituted HAP (ZnHAP) nanoparticles, in which silk fibroin was used as template. The morphology of HAP is rod-like, while ZnHAP changes to wrinkled sheets. HAP and ZnHAP nanoparticles were used to coat titanium by EPD with additional chitosan and multiwalled carbon nanotubes. Phase composition, morphology and structure were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared and Raman spectroscopy. The results showed that the composite coatings containing HAP and ZnHAP had homogeneous morphology and good apatite formation ability. The ZnHAP composite coating possessed class 5B adhesive strength using tape test. Furthermore, the ZnHAP composite coating had better corrosion resistance compared to the HAP composite coatings.

The biological bone minerals form within a complex microenvironment that consists of various ions and template molecules. Silk fibroin provides an attractive template for biomimetic hydroxyapatite synthesis. In this study, graphene-like zinc substituted hydroxyapatite crystals were prepared using silk fibroin and sodium alginate as template molecules, and the resulting products were investigated. The alginate ions interacted with silk fibroin, and the additional zinc ions also influenced the crystal formation of hydroxyapatite. The graphene-like sheets with hydroxyapatite phase were approximately 3 nm in thickness, and the size was more than 100 nm. The structure of the zinc substituted hydroxyapatite was studied by transmission electron microscopy, and the results revealed that small crystallites of several nanometers were assembled into large size sheets. The synergy effect of zinc and alginate ions led to the preferred growth along (002) and (211) orientations. Accordingly, the mechanisms of crystal gr...