Single atomic copper doping in ultrathin nitrogenated carbon nanosheets over 20.9 wt% was achieved, greatly boosting the oxygen reduction catalysis.

Developing efficient and stable electrocatalysts is crucial for the electrochemical production of pure and clean hydrogen. For practical applications, an economical and facile method of producing catalysts for the hydrogen evolution reaction (HER) is essential. Here, we report ruthenium (Ru) nanoparticles uniformly deposited on multi-walled carbon nanotubes (MWCNTs) as an efficient HER catalyst. The catalyst exhibits the small overpotentials of 13 and 17 mV at a current density of 10 mA cm-2 in 0.5 M aq. H 2 SO 4 and 1.0 M aq. KOH, respectively, surpassing the commercial Pt/C (16 mV and 33 mV). Moreover, the catalyst has excellent stability in both media, showing almost "zeroloss" during cycling. In a real device, the catalyst produces 15.4% more hydrogen per power consumed, and shows a higher Faradaic efficiency (92.28%) than the benchmark Pt/C (85.97%). Density functional theory calculations suggest that Ru-C bonding is the most plausible active site for the HER.

No abstract

There have been extensive efforts to synthesize crystalline covalent triazine-based frameworks (CTFs) for practical applications and to realize their potential. The phosphorus pentoxide (P O )-catalyzed direct condensation of aromatic amide instead of aromatic nitrile to form triazine rings. P O -catalyzed condensation was applied on terephthalamide to construct a covalent triazine-based framework (pCTF-1). This approach yielded highly crystalline pCTF-1 with high specific surface area (2034.1 m g ). At low pressure, the pCTF-1 showed high CO (21.9 wt % at 273 K) and H (1.75 wt % at 77 K) uptake capacities. The direct formation of a triazine-based COF was also confirmed by model reactions, with the P O -catalyzed condensation reaction of both benzamide and benzonitrile to form 1,3,5-triphenyl-2,4,6-triazine in high yield.

Catalysts are at the heart of the hydrogen evolution reaction (HER) for the production of pure and clean hydrogen. For practical applications, the scalable synthesis of efficient HER catalysts, which work in both acidic and alkaline media, is highly desired. In this work, the mechanochemically assisted synthesis of a Ru catalyst with HER performance surpassing Pt in both acidic and alkaline media is reported. Mass production of this Ru catalyst can be achieved via a two-step procedure: the mechanochemical reaction between graphite and dry ice produces edge-carboxylic-acid-functionalized graphene nanoplatelets (CGnP); mixing a Ru precursor and the CGnP in an aqueous medium introduces Ru ions, which coordinate on the CGnP. Subsequent annealing results in uniform Ru nanoparticles (≈2 nm) anchored on the GnP matrix (Ru@GnP). The efficient Ru@GnP catalyst can be easily powered by a single silicon solar cell using a wireless integration device. The self-powered device exhibits robust hydrogen evolution under the irradiation of standard AM 1.5 solar light. This work provides a new opportunity for the low-cost mass production of efficient and stable catalysts for practical applications.