Biomass-derived porous carbon material with sulfur and nitrogen dual-doping exhibits great potential for energy storage devices.

The porous nitrogen-doped hollow carbon spheres derived from polyaniline are promising electrode materials for high performance supercapacitors due to their hierarchical porous structure and nitrogen-doping.

This feature article reviews the recent progress of Li–S batteries to advance their practical uses.

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The proliferation and osteogenic capacity of mesenchymal stem cells (MSCs) needs to be improved for their use in cell-based therapy for osteoporosis. (-)-Epigallocatechin-3-gallate (EGCG), one of the green tea catechins, has been widely investigated in studies of osteoblasts and osteoclasts. However, no consensus on its role as an osteogenic inducer has been reached, possibly because of the various types of cell lines examined and the range of concentrations of EGCG used. In this study, the osteogenic effects of EGCG are studied in primary human bone-marrow-derived MSCs (hBMSCs) by detecting cell proliferation, alkaline phosphatase (ALP) activity and the expression of relevant osteogenic markers. Our results show that EGCG has a strong stimulatory effect on hBMSCs developing towards the osteogenic lineage, especially at a concentration of 5 μM, as evidenced by an increased ALP activity, the up-regulated expression of osteogenic genes and the formation of bone-like nodules. Further exploration has indicated that EGCG directes osteogenic differentiation via the continuous up-regulation of Runx2. The underlying mechanism might involve EGCG affects on osteogenic differentiation through the modulation of bone morphogenetic protein-2 expression. EGCG has also been found to promote the proliferation of hBMSCs in a dose-dependent manner. This might be associated with its antioxidative effect leading to favorable amounts of reactive oxygen species in the cellular environment. Our study thus indicates that EGCG can be used as a pro-osteogenic agent for the stem-cell-based therapy of osteoporosis.

An improved cycling performance of sulfur cathodes is attributed to the synergistic effect of PAA and PEDOT:PSS.

This work reports the nanocomposites of graphitic nanofibers (GNFs) and carbon nanotubes (CNTs) as the electrode material for supercapacitors. The hybrid CNTs/GNFs was prepared via a synthesis route that involved catalytic chemical vapor deposition (CVD) method. The structure and morphology of CNTs/GNFs can be precisely controlled by adjusting the flow rates of reactant gases. The nest shape entanglement of CNTs and GNFs which could not only have high conductivity to facilitate ion transmission, but could also increase surface area for more electrolyte ions access. When assembled in a symmetric two-electrode system, the CNTs/GNFs-based supercapacitor showed a very good cycling stability of 96% after 10 000 charge/discharge cycles. Moreover, CNTs/GNFs-based symmetric device can deliver a maximum specific energy of 72.2 Wh kg−1 at a power density of 686.0 W kg−1. The high performance of the hybrid performance can be attributed to the wheat like GNFs which provide sufficient accessible sites for charge storage, and the CNTs skeleton which provide channels for charge transport.

In this work, phytic acid is used as protonic acid dopant and soft template to synthesize 3D polyaniline (PANI) nanofiber networks. Then, the PANI nanofiber networks are transformed to porous nitrogen and phosphorus co-doped carbon nanofibers (P-NP-CNFs) by the carbonization and chemical activation process. P-NP-CNFs have a high specific surface area of 2586 m 2 g -1 and large pore volume of 1.43 cm 3 g -1 , which are in favour of enhancing the electrochemical performance for electrical double layer 10 capacitors. Moerover, the nitrogen and phosphorus doping in the carbon materials can increase the specific capacitance by a pseudocapacitive redox process. At a current density of 1 A g -1 , P-NP-CNFs show a large specific capacitance of 280 F g -1 and high specific capacitance retention of 94% after 10000 cycles. Especially, the phosphorus doping can broaden the electrochemical window to increase the energy density. Therefore, the energy density of symmetric capacitors based on P-NP-CNF is up to 22.9 Wh kg -1 15 at a power density of 325 W kg -1 , demonstrating P-NP-CNFs are superior electrode materials for electrical double layer capacitors. 65 Herein, a simple and fast (several minutes) method was applied to synthesize the nitrogen and phosphorus co-doped carbon material precursor. 10,11,32 In the synthesis process, aniline was used as nitrogen source, phytic acid as dopant, phosphorus source and soft template to form 3D polyaniline (PANI) nanofiber 70 networks. Then, a combined carbonization and chemical activation process in an inert gas was implemented to achieve porous nitrogen and phosphorus co-doped carbon nanofiber Journal Name, [year], [vol], 00-00 | 3 65 surface area of NP-CNFs (421 m 2 g -1 ) is increased compared with that of PANI nanofibers (26 m 2 g -1 , Figure S5). After the KOH chemical activation, the specific surface area of P-NP-CNFs is 2586 m 2 g -1 . The pore volume of P-NP-CNFs (1.43 cm 3 g -1 ) is greatly larger than that of NP-CNFs (0.18 cm 3 g -1 , Figure 4d). 70 Then, XPS was carried out to detect the nitrogen and phosphorus bonds for NP-CNFs and P-NP-CNFs. The amounts of nitrogen and phosphorus are 7.1%, 3.6% in NP-CNFs and 4.4%, 2.8% in P-NP-CNFs, respectively ( Table S1). The nitrogen peaks of NP-CNFs and P-NP-CNFs can be matched into four peaks at 403.3, 75