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Non-noble metal single-atoms catalysts hold great promise in selective oxidation reactions, although the progress is still unsatisfied because of the synthetic challenge and the lack of mechanistic interpretations. Herein, we...

Two‐dimensional carbons synthesis through sustainable bio‐manufacturing methods has attracted much attention in the past decade. This process facilitates low cost and facile manufacturing of porous carbon materials with specific characteristics, as well as chemical functions that differ from their bulk counterparts due to the low dimensionality. Herein, a unique graphene‐like carbon framework composed of three‐dimensionally interconnected nanosheets has been successfully fabricated via carbonization of a biomass precursor guanine and colloidal silica. The obtained two‐dimensional carbon materials, consisting of carbon nanosheets with varying sizes, can provide huge exposed areas. Owing to the merits of in situ nitrogen‐doping, particularly the optimization of nitrogen species and significant improvement in porosity, the sample GHS‐1000‐2.5 delivers the outstanding electrochemical activity towards oxygen reduction reaction in both acid and alkaline conditions, which are comparable to the commercial Pt/C catalyst and show even better performance under the same conditions. This highly efficient, facile and low‐cost strategy is expected to meet the requirements for the commercialization for fuel cells.

Hydrothermal carbonization (HTC) technology shows a powerful way to transform biomass into new carbonaceous materials. However, because of weak interactions between biomass, the nucleation/polymerization process of HTC carbon follows the random polymerization mechanism, tending to form spherical particles with very few micro/mesopores and very small surface areas. Herein, we report an acid-assisted HTC strategy to fabricate a new family of hydrothermal carbons with super-high surface areas from nucleoside precursors, namely, guanosine, adenosine, and inosine. Among them, HTC carbons derived from guanosine show obviously layered graphitic characteristics potentially owing to the strong multiple hydrogen bonding and π−π interaction between guanosine, while the materials prepared from inosine and adenosine are composed of large-size spherical carbon particles. Ex-situ characterizations confirm that guanosine first decomposes into guanine and ribose under acid-assisted HTC conditions to form bulky guanine sulfate. The guanine sulfate then self-assembles to CN oligomers; meanwhile, the ribose is dehydrated to furfural. The CN oligomer finally reacts with furfural to obtain the composite composed of layered CN polymers and HTC carbon. Owing to the self-templated effect, all HTC carbons can be transformed into carbon with ultrahigh surface areas (∼1700 m 2 •g −1 ) by further pyrolysis at 1000 °C. The electrochemical test indicates that these nucleoside-derived carbon materials have excellent activity in oxygen reduction reaction, especially for the guanosine-derived carbon, exhibiting excellent electrocatalytic activity with a half-wave potential of 0.88 V and a limit current density of 5.84 mA•cm −2 , which are quite close to those of a commercial Pt/C catalyst.

No abstract

Presented here is a facile, sustainable and green method for the synthesis of N-doped carbon microspheres/nanosheets via hydrothermal carbonization (HTC) of the selected bioprecursor guanosine.

We report the utilization of guanosine as a supramolecular precursor that unprecedentedly renders the formation of carbon-based multilayer materials with naturally high-level nitrogen doping. As a proof-of-concept, the porous carbon...

Developing low-cost and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) has stimulated extensive interest. Molybdenum carbide materials have been proposed as promising alternatives to noble platinum-based catalysts due...