Graphene-like nitrogen-doped carbon nanosheets (NCN) have become a fascinating carbon-based material for advanced energy storage and conversion devices, but its easy, cheap, and environmentally friendly synthesis is still a grand challenge. Herein we directly synthesized porous NCN material via the facile pyrolysis of chitosan and urea without the requirement of any catalyst or post-treatment. As-prepared material exhibits a very large BET surface area of ~1510 m(2) g(-1) and a high ratio of graphitic/pyridinic nitrogen structure (2.69 at. % graphitic N and 1.20 at. % pyridinic N). Moreover, compared to a commercial Pt/C catalyst, NCN displays excellent electrocatalytic activity, better long-term stability, and methanol tolerance ability toward the oxygen reduction reaction, indicating a promising metal-free alternative to Pt-based cathode catalysts in alkaline fuel cells. This scalable fabrication method supplies a low-cost, high-efficiency metal-free oxygen reduction electrocatalyst and also suggests an economic and sustainable route from biomass-based molecules to value-added nanocarbon materials.

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The design and fabrication of oxygen reduction reaction (ORR) electrocatalysts with high performance at low cost remains a big challenge but is crucial for the commercialization of fuel cells. Here, we report a simple and economical method for the direct mass production of nitrogen/sulfur co‐doped graphene (NS‐G) by using cysteine as single precursor and self‐assembled NaCl as a structure‐directing template through the solid‐phase pyrolysis method. The resultant NS‐G possesses a high specific surface area of 435.13 m2 g−1, effective N (1.85 at %) and S (0.99 at %) dual doping and enhanced conductivity, which contribute largely to the exposure of highly active sites and to the promotion of electron transport in the ORR process. Accordingly, the NS‐G exhibits excellent ORR performance with a positive half‐wave potential of 0.768 V (versus reversible hydrogen electrode), four‐electron pathway, low Tafel slope of 60 mV dec−1, and high stability in alkaline medium. These merits make NS‐G a promising alternative to costly Pt for ORR.

3D N,P,Co-doped mesoporous carbon frameworks synthesizedviaa new self-growth-templating approach enable efficient bifunctional electrocatalysis in the ORR and CO2RR.

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Self-assemly of block copolymers (BCPs) and phenolic resin (PR) is an important method to prepare ordered mesoporous polymers (OMPs) and carbon materials (OMCs). In the process, phase separation of the BCP–PR composite is a critical step which is, however, time-consuming in aqueous solution. Here we report, for the first time, a new salt-induced phase separation strategy to achieve this goal. Triblock copolymer F127 and phenol-formaldehyde resin (PF) are used as the template and precursor, respectively, and sodium chloride (NaCl) is applied to induce the coagulation and phase separation of the F127–PF composite which is transformed to be OMC at high temperature. It is found that the maintenance of the ordered mesostructure is highly dependent on the pH of the F127–PF solution under NaCl interference. A hypothetical mechanism is proposed to explain the role of pH in the formation of ordered mesostructure when salt is introduced into the self-assembly system. The effects of pH, salt concentration, and varied salts on the structures and properties of the as-prepared OMCs are investigated in detail. The new salt-induced phase separation strategy can synthesize OMC facilely and can provide a new insight into understanding the process of preparing ordered mesoporous materials by self-assembly more deeply.

In this work, we synthesized Prussian Blue (PB) by pyrolysis of nitrogen-rich organic compounds and ferric/ferrous salts in the presence of alkali metal salt in inert atmosphere at high temperature, which was completely different form popular method based on the reaction of ferric ions and ferrocyanide ions. By exploring the history of Prussian Blue and some research results, we proposed a possible mechanism to explain the formation of Prussian Blue. The mechanism is as follows: Firstly, carbon, nitrogen and oxygen element in the mixture were transformed to cyanate by the catalysis of alkali metal species. With the increasing of temperature, organic compounds decomposed to release reducing gases such as H₂ and CO and eventually formed carbon materials. The reducing gases reduced part of Fe³⁺ to Fe²⁺ and the carbon reduced the cyanate to cyanide. So Prussian Blue was formed by cyanide, Fe³⁺ and Fe²⁺. The most import substance in the process is the alkali salts and a key intermediate product namely cyanate is proposed. Detailed experiments can be found in PDF file.

In this work, we synthesized Prussian Blue (PB) by pyrolysis of nitrogen-rich organic compounds and ferric/ferrous salts in the presence of alkali metal salt in inert atmosphere at high temperature, which was completely different form popular method based on the reaction of ferric ions and ferrocyanide ions. By exploring the history of Prussian Blue and some research results, we proposed a possible mechanism to explain the formation of Prussian Blue. The mechanism is as follows: Firstly, carbon, nitrogen and oxygen element in the mixture were transformed to cyanate by the catalysis of alkali metal species. With the increasing of temperature, organic compounds decomposed to release reducing gases such as H₂ and CO and eventually formed carbon materials. The reducing gases reduced part of Fe³⁺ to Fe²⁺ and the carbon reduced the cyanate to cyanide. So Prussian Blue was formed by cyanide, Fe³⁺ and Fe²⁺. The most import substance in the process is the alkali salts and a key intermediate product namely cyanate is proposed. Detailed experiments can be found in PDF file.