MoC is a possible substitute to Pt-group metals for electrocatalytic hydrogen evolution reaction (HER). Both support-free and carbon-supported MoC nanomaterials with improved HER performance have been developed. Herein, distinct from prior research, novel ordered mesoporous core-shell nanowires with MoC cores and ultrathin graphitic carbon (GC) shells are rationally synthesized and demonstrated to be excellent for HER. The synthesis is fulfilled via a hard-templating approach combining in situ carburization and localized carbon deposition. Phosphomolybdic acid confined in the SBA-15 template is first converted to MoO, which is then in situ carburized to MoC nanowires with abundant surface defects. Simultaneously, GC layer (the thickness is down to ∼1.0 nm in most areas) is controlled to be locally deposited on the MoC surface because of its strong affinity with carbon and catalytic effect on graphitization. Removal of the template results in the MoC@GC core-shell nanowire arrays with the structural properties well-characterized. They exhibit excellent performance for HER with a low overpotential of 125 mV at 10 mA cm, a small Tafel slope of 66 mV dec, and an excellent stability in acidic electrolytes. The influences of several factors, especially the spatial configuration and relative contents of the GC and MoC components, on HER performance are elucidated with control experiments. The excellent HER performance of the mesoporous MoC@GC core-shell nanowire arrays originates from the rough MoC nanowires with diverse active sites and short charge-transfer paths and the ultrathin GC shells with improved surface area, electronic conductivity, and stabilizing effect on MoC.

HIGHLIGHTS• An in situ molecular foaming and activation strategy is designed and investigated for the synthesis of hierarchically porous N-doped carbon foams (HPNCFs).• The prepared HPNCFs possess 3D macropores, uniform micropores and mesopores, ultrahigh surface areas and high N contents and show high performances in supercapacitors and CO 2 capture.ABSTRACT Hierarchically porous carbon materials are promising for energy storage, separation and catalysis. It is desirable but fairly challenging to simultaneously create ultrahigh surface areas, large pore volumes and high N contents in these materials. Herein, we demonstrate a facile acid-base enabled in situ molecular foaming and activation strategy for the synthesis of hierarchically macro-/meso-/microporous N-doped carbon foams (HPNCFs). The key design for the synthesis is the selection of histidine (His) and potassium bicarbonate (PBC) to allow the formation of 3D foam structures by in situ foaming, the PBC/His acid-base reaction to enable a molecular mixing and subsequent a uniform chemical activation, and the stable imidazole moiety in His to sustain high N contents after carbonization. The formation mechanism of the HPNCFs is studied in detail. The prepared HPNCFs possess 3D macroporous frameworks with thin well-graphitized carbon walls, ultrahigh surface areas (up to 3200 m 2 g −1 ), large pore volumes (up to 2.0 cm 3 g −1 ), high micropore volumes (up to 0.67 cm 3 g −1 ), narrowly distributed micropores and mesopores and high N contents (up to 14.6 wt%) with pyrrolic N as the predominant N site. The HPNCFs are promising for supercapacitors with high specific capacitances (185-240 F g −1 ), good rate capability and excellent stability. They are also excellent for CO 2 capture with a high adsorption capacity (~ 4.13 mmol g −1 ), a large isosteric heat of adsorption (26.5 kJ mol −1 ) and an excellent CO 2 /N 2 selectivity (~ 24). on the two isotherms wherein the adsorption capacities are the same.

A solvent-free assembly approach via directly heating amino acid and mesoporous silica mixtures is developed for the synthesis of a family of highly nitrogen-doped mesoporous carbons. Amino acids have been used as the sole precursors for templating synthesis of a series of ordered mesoporous carbons. During heating, amino acids are melt and strongly interact with silica, leading to effective loading and improved carbon yields (up to ~ 25 wt%), thus to successful structure replication and N-doping. Unique solvent-free structure assembly mechanisms are proposed and elucidated semiquantitatively by using two affinity scales. Significantly high N-doping levels are achieved, up to 9.4 (16.0) wt% via carbonization at 900 (700) °C. The diverse types of amino acids, their variable interactions with silica and different pyrolytic behaviors lead to N-doped mesoporous carbons with tunable surface areas (700 ~ 1400 m 2 g -1 ), pore volumes (0.9 ~ 2.5 cm 3 g -1 ), pore sizes (4.3 ~ 10 nm), and particle sizes from a single template. As demonstrations, the typical nitrogen-doped carbons show good performance in CO 2 capture with high CO 2 /N 2 selectivities up to ~ 48. Moreover, they show attractive performance for oxygen reduction reaction, with an onset and a half-wave potential of ~ -0.06 and -0.14 V (vs. Ag/AgCl).

The blood-brain barrier (BBB) severely blocks the intracranial accumulation of most systemic drugs. Inspired by the contribution of the bacterial outer membrane to Escherichia coli K1 (EC-K1) binding to and invasion of BBB endothelial cells in bacterial meningitis, utilization of the BBB invasion ability of the EC-K1 outer membrane for brain-targeted drug delivery and construction of a biomimetic self-assembled nanoparticle with a surface featuring a lipopolysaccharide-free EC-K1 outer membrane are proposed. BBB penetration of biomimetic nanoparticles is demonstrated to occur through the transcellular vesicle transport pathway, which is at least partially dependent on internalization, endosomal escape, and transcytosis mediated by the interactions between outer membrane protein A and gp96 on BBB endothelial cells. This biomimetic nanoengineering strategy endows the loaded drugs with prolonged circulation, intracranial interstitial distribution, and extremely high biocompatibility. Based on the critical roles of gp96 in cancer biology, this strategy reveals enormous potential for delivering therapeutics to treat gp96-overexpressing intracranial malignancies.

A novel protein-based polymer is deliberately synthesized by the polymerization reaction using the silk fibroin protein (SFP) and 2-isocyanatoethyl methacrylate. The analog-type protein-based memristor demonstrates that more than 32 conductance...