Tuning the chemical composition, textural and capacitance properties of mesoporous graphitic carbon nitride

Recent Advances in Mesoporous Carbon Nitride-Based Materials for Electrochemical Energy Storage and Conversion and Gas Storage

Mesoporous carbon nitride (MCN) is a fascinating material with enhanced textural properties, tailored morphology and enriched surface functionalities. Hence, it demonstrates promising performance in various applications. Over the years, various methods such as hard template, soft template, template-free, etc. have been adopted toward the preparation of MCN with controlled structural properties. Furthermore, the exciting properties of MCN have been fine-tuned by controlling the morphology and tuning the textural properties and surface functionalities, including the type and amount of nitrogen, via simple adjustment of the precursors, the carbonization temperature and the nature of the structure-directing agents/hard template. Besides these, the integration of conductive carbon, heteroatoms, metal-based materials, organic molecules, etc. was found to not only enhance MCN's performance in the already existing applications but also open up more exciting applications. The present Review begins by providing a general overview of the salient features of MCN, which dictate its performance in the various applications. Then, the Review discusses the trends in the applications of MCN-based material in the areas of electrochemical energy storage and conversion and gas storage in the past decade. The structure-property relationships of MCN-based materials in the above-mentioned applications are also discussed in detail. Emphasis is given to the role of the synthetic approach adopted and the nature of the precursor(s) used toward controlling the textural, morphological properties and chemical composition of MCN-based materials in obtaining the final product with improved performance. Moreover, the effects of modifications of key features of MCN on its electrochemical performance are also discussed. Finally, the current challenges and perspectives are provided, thereby guiding future research in the field of MCN-based materials for electrochemical energy storage and conversion and gas storage.

Mesoporous carbon nitride supported MgO for enhanced CO2 capture

The growing concern about the environmental consequences of anthropogenic CO2 emissions significantly stimulated the research of low-cost, efficient, and recyclable solid adsorbents for CO2 capture. In this work, a series of MgO-supported mesoporous carbon nitride adsorbents with different MgO contents (xMgO/MCN) was prepared using a facile process. The obtained materials were tested for CO2 capture from 10 vol% CO2 mixture gas with N2 using a fixed bed adsorber at atmospheric pressure. At 25 ºC, the bare MCN support and unsupported MgO samples demonstrated CO2 capture capacities of 0.99, and 0.74 mmol g-1, respectively, which were lower than those of the xMgO/MCN composites.The incorporation of MgO into the MCN improved the CO2 uptake, and the 20MgO/MCN exhibited the highest CO2 capture capacity of 1.15 mmol g-1 at 25 °C. The improved performance of the 20MgO/MCN nanohybrid can be possibly assigned to the presence of high content of highly dispersed MgO NPs along with its improved textural properties in terms of high specific surface area (215 m2g-1), large pore volume (0.22 cm3g-1), and abundant mesoporous structure. The efffects of temperature and CO2 flow rate were also investigated on the CO2 capture performance of 20MgO/MCN. Temperature was found to have a negative influence on the CO2 capture capacity of the 20MgO/MCN, which decreased from 1.15 to 0.65 mmol g-1with temperature rise from 25 C to 150º C, due to the endothermicity of the process. Similarly, the capture capacity decreased from 1.15 to 0.54 mmol g-1 with the increase of the flow rate from 50 to 200 ml minute-1 respectively. Importantly, 20MgO/MCN showed excellent reusability with consistent CO2 capture capacity over five sequential sorption-desorption cycles, suggesting its suitability for the practical capture of CO2.

From polymeric carbon nitride to carbon materials: extended application to electrochemical energy conversion and storage

As an emerging photocatalyst, polymeric carbon nitride (PCN) currently has drawn ever-increasing attention for electrochemical energy conversion and storage due to its graphite-like structure, metal-free characteristic and excellent structural tunability. Nonetheless, its practical applications are still hindered by the poor electrical conductivity induced irreversible capacity loss. Recently, PCN-derived carbon materials with improved conductivity have received increasing interest and made tremendous progress for advanced electrochemical energy conversion and storage. This review highlights the latest research advancements regarding the electrochemical energy conversion (hydrogen evolution reaction, oxygen reduction/evolution reaction, nitrogen reduction reaction, carbon dioxide reduction reaction, etc.) and storage (Li-ion batteries, Li-S batteries, supercapacitors, etc.) application from PCN to PCN-derived carbon materials. A perspective about the challenges and trends in the electrochemical application of PCN and PCN-derived carbon materials is also provided at the end of the review.

Graphitic Carbon Nitride Doped Copper-Manganese Alloy as High-Performance Electrode Material in Supercapacitor for Energy Storage

Here, we report the synthesis of copper-manganese alloy (CuMnO₂) using graphitic carbon nitride (gCN) as a novel support material. The successful formation of CuMnO₂-gCN was confirmed through spectroscopic, optical, and other characterization techniques. We have applied this catalyst as the energy storage material in the alkaline media and it has shown good catalytic behavior in supercapacitor applications. The CuMnO₂-gCN demonstrates outstanding electrocapacitive performance, having high capacitance (817.85 A·g^-1) and well-cycling stability (1000 cycles) when used as a working electrode material for supercapacitor applications. For comparison, we have also used the gCN and Cu₂O-gCN for supercapacitor applications. This study proposes a simple path for the extensive construction of self-attaining double metal alloy with control size and uniformity in high-performance energy-storing materials.

Few-layered mesoporous graphitic carbon nitride: a graphene analogue with high capacitance properties

Exfoliation of multi-layered MGCN into few-layered MGCN results in 50% enhancement in the specific capacitance value.