COMMUNICATION Figure 5. a) Cycling performance of binder-free porous CNAs, CuO nanorods scraped off of Cu foil, and CuO nanosheets. b) Rate capability of different CuO electrodes at various current densities from 0.02 to 1 A g −1 . c) Cycling performance of binder-free CNA electrode at a high current density of 200 mA g −1 . d) Schematic diagram showing the strategy for binder-free CNA electrode.www.advmat.de www.MaterialsViews.com wileyonlinelibrary.com

Xin-Bo Zhang et al. 3D ordered macroporous LaFeO 3 as effi cient electrocatalyst for Li-O 2 batteries with enhanced rate capability and cyclic performance

Research on incorporation of both growth factors and silver (Ag) into hydroxyapatite (HA) coatings on metallic implant surfaces for enhancing osteoinductivity and antibacterial properties is a challenging work. Generally, Ag nanoparticles are easy to agglomerate and lead to a large increase in local Ag concentration, which could potentially affect cell activity. On the other hand, growth factors immobilization requires mild processing conditions so as to maintain their activities. In this study, bone morphology protein-2 (BMP-2) and Ag nanoparticle contained HA coatings were prepared on Ti surfaces by combining electrochemical deposition (ED) of Ag and electrostatic immobilization of BMP-2. During the ED process, chitosan (CS) was selected as the stabilizing agent to chelate Ag ions and generate Ag nanoparticles that are uniformly distributed in the coatings. CS also reduces Ag toxicity while retaining its antibacterial activity. Afterwards, a BMP/heparin solution was absorbed on the CS/Ag/HA coatings. Consequently, BMP-2 was immobilized on the coatings by the electrostatic attraction between CS, heparin, and BMP-2. Sustained release of BMP-2 and Ag ions from HA coatings was successfully demonstrated for a long period. Results of antibacterial tests indicate that the CS/Ag/HA coatings have high antibacterial properties against both Staphylococcus epidermidis and Escherichia coli. Osteoblasts (OB) culture reveals that the CS/Ag/HA coatings exhibit good biocompatibility. Bone marrow stromal cells (BMSCs) culture indicates that the BMP/CS/Ag/HA coatings have good osteoinductivity and promote the differentiation of BMSCs. Ti bars with BMP/CS/Ag/HA coatings were implanted into the femur of rabbits to evaluate the osteoinductivity of the coatings. Results indicate that BMP/CS/Ag/HA coatings favor bone formation in vivo. In summary, this study presents a convenient and effective method for the incorporation of growth factors and antibacterial agents into HA coatings. This method can be utilized to modify a variety of metallic implant surfaces.

With the availability of various types of two-dimensional materials such as graphene (GE) and MoS 2 , intensive efforts have been devoted to their van der Waals heterostructures obtained by vertically stacking them together for novel functionalities and applications. The thermal transport behavior of these heterostructures plays a pivotal role in determining their functional performance. This work studies the thermal transport in a GE-MoS 2 bilayer heterostructure via molecular dynamics simulation. It is found that the in-plane thermal conductivity l B of the GE-MoS 2 bilayer can be approximated by that of an isolated monolayer GE. The l B of an infinitely long GE-MoS 2 bilayer is calculated to be 1037 W m À1 K À1 , while its out-of-plane interface thermal conductance G is obtained as 5.81 MW m À2 K À1 . The increase in the interface coupling strengths can dramatically increase G but has little effect on l B . On the other hand, G also increases with temperature because of the enhanced phonon coupling between GE and MoS 2 . This study is helpful for understanding the interface thermal transport behaviors of novel van der Waals heterostructures and could provide guidance for optimal design and control of their thermal properties.

Formic acid (FA) holds great potential as a convenient source of hydrogen for sustainable chemical synthesis and renewable energy storage. Herein, the non-noble metal nickel (Ni) exhibits superior promoting effect in improving the catalytic activity of Pd toward high activity and selectivity for FA decomposition at room temperature.

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Bone morphology protein-2 (BMP-2) encapsulated chitosan/chondrotin sulfate nanoparticles (CHI/CS NPs) are developed to enhance ectopic bone formation on biphasic calcium phosphate (BCP) scaffolds. BMP-2 contained CHI/CS NPs were prepared by a simple and mild polyelectrolyte complexation process. It does not involve harsh organic solvents and high temperature, and therefore retain growth factors activity. These NPs were immobilized on BCP scaffolds, and realize the sustained release of growth factors from the scaffolds. The bare BCP scaffolds, NP loaded scaffolds (BCP-NP), and NP loaded and polydopamine coated scaffolds (BCP-Dop-NP) were seeded with bone marrow stroma cells (BMSC) to evaluate the osteoinductivity of the scaffolds. BMSC culture results indicate that all scaffolds favor cell adhesion, proliferation, differentiation. Afterwards, the bare BCP, BCP-NP, and BCP-Dop-NP scaffolds were implanted into rabbits intramuscularly to evaluate the ectopic bone formation of scaffolds. In vivo results indicate that the BCP-NP and BCP-Dop-NP scaffolds enhance more ectopic bone formation than the bare BCP scaffolds. Both the in vitro and in vivo results demonstrate that BMP-2 encapsulated polysaccharide NPs are effective to improve the osteoinductivity of the scaffolds. In addition, BCP-NP scaffolds induce more bone formation than BCP-Dop-NP scaffolds. This is because BCP-NP scaffolds harness the intrinsic osteoinductivity BCP and BMP-2, whereas BCP-Dop-NP scaffolds have polydopamine coatings that inhibit the surfaces biological features of BCP scaffolds, and therefore weaken the bone formation ability of scaffolds.