Mesoporous carbon nitrides (MCNs) with large surface areas and uniform pore diameters are unique semiconducting materials and exhibit highly versatile structural and excellent physicochemical properties, which promote their application in diverse fields such as metal free catalysis, photocatalytic water splitting, energy storage and conversion, gas adsorption, separation, and even sensing. These fascinating MCN materials can be obtained through the polymerization of different aromatic and/or aliphatic carbons and high nitrogen containing molecular precursors via hard and/or soft templating approaches. One of the unique characteristics of these materials is that they exhibit both semiconducting and basic properties, which make them excellent platforms for the photoelectrochemical conversion and sensing of molecules such as CO, and the selective sensing of toxic organic acids. The semiconducting features of these materials are finely controlled by varying the nitrogen content or local electronic structure of the MCNs. The incorporation of different functionalities including metal nanoparticles or organic molecules is further achieved in various ways to develop new electronic, semiconducting, catalytic, and energy harvesting materials. Dual functionalities including acidic and basic groups are also introduced in the wall structure of MCNs through simple UV-light irradiation, which offers enzyme-like properties in a single MCN system. In this review article, we summarize and highlight the existing literature covering every aspect of MCNs including their templating synthesis, modification and functionalization, and potential applications of these MCN materials with an overview of the key and relevant results. A special emphasis is given on the catalytic applications of MCNs including hydrogenation, oxidation, photocatalysis, and CO activation.

Mesoporous carbon nitrides (MCN) are fascinating materials with unique semiconducting and basic properties that are useful in many applications including photocatalysis and sensing. Most syntheses of MCN focus on creating theoretically predicted C 3 N 4 stoichiometry with ab and gap of 2.7 eV using an ano-hardt emplating approach with triazine-based precursors.However,the performance of the MCN in semiconducting applications is limited to the MCN framework with as mall band gap,whichwould be linked with the addition of more N in the CN framework, but this remains ahuge challenge.Here, we report ap recursor with high nitrogen content, 3-amino-1,2,4-triazole,t hat enables the formation of new and wellordered 3D MCN with C 3 N 5 stoichiometry (MCN-8), which has not been predicted so far,a nd al ow-band-gape nergy (2.2 eV). This novel class of material without addition of any dopants shows not only as uperior photocatalytic watersplitting performance with at otal of 801 mmol of H 2 under visible-light irradiation for 3h but also excellent sensing properties for toxic acids.Carbon nitrides (CN) are of particular importance because of their unique properties such as high bulk moduli, low density,high thermal conductivity,semiconductivity,biocompatibility,a nd tunability of band gaps.[1] These properties make them special and help to advance their performance in various applications including adsorption, gas storage,photocatalysis,e nergy storage,a nd sensing.[2-4] However,t he efficiency of these materials in the above applications is related to their crystal structure,p orosity,a nd most importantly the nitrogen content in the CN framework. The porosity in CN was first realized by Vinu et al. who used the hard templating approach for creating CN with ahigh specific surface area and remarkable pore structures. [5,6] These materials suffer from poor nitrogen content due to al ow thermodynamic stability of Ni nt he carbon framework at ahigh temperature,which limits their performance in various applications.T his triggers various research groups to develop different preparation routes for porous CN by annealing the precursors with high nitrogen content at ahigh temperature. Forexample,non-porous graphitic C 3 N 4 has been prepared by using different Nrich precursors such as cyanamide,thiourea, ammonium thiocyanate,m elamine,u rea, and cyanuric chloride.[4] On the other hand, mesoporous carbon nitrides (MCN) can be prepared by anano-hard templating approach using nitrogen-containing precursors such as triazine or cyanamide or guanidine. [7][8][9][10] Then itrogen content of these materials are limited to the C/N ratio higher than 0.75 (C 3 N 4 ), which generally provides CN walls with triazine network. [11,12] In contrast to MCN with the stoichiometry of C 3 N 4 ,MCN with C 3 N 5 framework has not been synthesized as it is challenging and requires modification of the CN framework structure in order to introduce more nitrogen into the triazine network. MCN with C 3 N 5 and well-ordered porous structure could sign...

Synthesis and excellent photocatalytic H2 evolution performance of diaminotetrazine based highly ordered 3D mesoporous carbon nitrides (MCN-9) with C3N6 stoichiometry prepared by employing KIT-6 silica template has been demonstrated.

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Wound healing is a dynamic and complex process of tissue repair that involves a number of cellular and molecular events. It proceeds from inflammatory response to reepithelialization and finally to formation of a permanent scar. Alginate is a polymer of guluronic and mannuronic acid that is used as a scaffolding material in biomedical applications. For the purpose of studying wound healing, full-thickness skin defects were produced on the dorsal area in rats. We measured the relative sizes of the wounds on days 3, 5, 7, 14, and 28. The wound sizes were decreased in the alginate-treated group compared with the control group and the vaseline-treated group. The expressions of transforming growth factor-beta1, fibronectin, and vascular endothelial growth factor were significantly decreased in the alginate-treated group compared with the control group, while the expression of collagen-I was increased in the alginate-treated group, as indicated by Western blotting and immunohistochemical staining. These data suggest that alginate has significant wound healing promoting activity. The results from the present study indicate that the effect of alginate on wound healing may involve biological mechanisms associated with the expression of transforming growth factor-beta1, fibronectin, vascular endothelial growth factor, and collagen-I.