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...

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Heteropoly acids (HPAs) are unique materials with interesting properties, including high acidity and proton conductivity. However, their low specific surface area and high solubility in polar solvents make them unattractive for catalytic or energy applications. This obstacle can be overcome by creating nanoporosity within the HPA. We synthesized mesoporous phosphotungstic acid (mPTA) with a spherical morphology through the self‐assembly of phosphotungstic acid (PTA) with a polymeric surfactant as stabilized by KCl and hydrothermal treatment. The mPTA nanostructures had a surface area of 93 m2 g−1 and a pore size of 4 nm. Their high thermal stability (ca. 450 °C) and lack of solubility in ethylene carbonate/diethyl carbonate (EC/DEC) electrolyte are beneficial for lithium‐ion batteries (LIBs). Optimized mPTA showed a reversible capacity of 872 mAh g−1 at 0.1 A g−1 even after 100 cycles for LIBs, as attributed to a super‐reduced state of HPA and the storage of Li ions within the mesochannels of mPTA.

Highly ordered mesoporous C with a well-ordered porous structure and a high crystallinity is prepared through the nanohard templating method using a saturated solution of C in 1-chloronaphthalene (51 mg mL ) as a C precursor and SBA-15 as a hard template. The high solubility of C in 1-chloronaphthalene helps not only to encapsulate a huge amount of the C into the mesopores of the template but also supports the oligomerization of C and the formation of crystalline walls made of C . The obtained mesoporous C exhibits a rod-shaped morphology, a high specific surface area (680 m g ), tuneable pores, and a highly crystalline wall structure. This exciting ordered mesoporous C offers high supercapacitive performance and a high selectivity to H O production and methanol tolerance for ORR. This simple strategy could be adopted to make a series of mesoporous fullerenes with different structures and carbon atoms as a new class of energy materials.