Electrochemical Energy Storage Using Carbon Nitride-Based Supercapacitors

Graphitic carbon nitride (g-C3N4) has emerged as a versatile and sustainable electrode material for supercapacitors, combining a layered two-dimensional structure with high nitrogen content. Its intrinsic pseudocapacitive behaviour arises from abundant nitrogen sites that facilitate faradaic reactions, while the conjugated network supports double-layer charge storage. However, pristine g-C3N4 suffers from limited electrical conductivity and restricted ion diffusion due to layer stacking. Recent strategies focus on structural engineering and hybridisation to overcome these limitations. Exfoliation of bulk g-C3N4 into nanosheets increases accessible surface area and exposes active edge sites. Introduction of hierarchical porosity further shortens ion diffusion pathways, while integration with conductive substrates such as reduced graphene oxide, carbon fibres or metal foams enhances electron transport. Composite architectures with metal oxides, sulphides or transition metal alloys add redox-active components that boost energy density without sacrificing cycle life. Flexible and tubular configurations open avenues in wearable electronics and grid-scale energy buffering. These advances sustain high power density, rapid charge–discharge kinetics and extended operational stability, underpinning the global transition towards renewable energy systems and electric mobility.

Research from Nature Portfolio

One interdisciplinary study reports a hybrid electrode formed by ultrathin nickel hydroxide nanosheets uniformly supported on a porous network of graphitic carbon nitride and reduced graphene oxide. The sandwich-like architecture offers large surface area and tailored pore size distribution, yielding a specific capacitance approaching 1800 F g–1 at moderate current densities and robust cycle retention over thousands of cycles. Another work introduces a hollow tubular supercapacitor fabricated via a scalable two-step process to produce flexible devices resembling electrical wiring. This novel geometry achieves energy densities exceeding those of commercial film devices, retains performance under mechanical deformation and demonstrates stable capacitance over 10 000 bending cycles, highlighting the potential for integration in flexible and wearable systems.

Electrochemical Energy Storage Using Carbon Nitride-Based Supercapacitors publication trend

The graph below shows the total number of articles in electrochemical energy storage using carbon nitride-based supercapacitors across all publications each year (not limited to Nature Index journals).

Technical terms

Graphitic carbon nitride (g-C3N4): A two-dimensional polymeric semiconductor composed of carbon and nitrogen, used as a pseudocapacitive electrode material.

Specific capacitance: The capacitance per unit mass of electrode material, expressed in farads per gram (F g–1), indicating charge storage capability.

Pseudocapacitance: Charge storage arising from fast, reversible redox reactions at or near the electrode surface, distinct from electrostatic double-layer capacitance.

Exfoliation: The process of separating bulk layered materials into thinner nanosheets to increase surface area and active sites.

Asymmetric device: A supercapacitor configuration using different materials for positive and negative electrodes to broaden voltage window and enhance energy density.

References

1. Improving the charge kinetics through in-situ growth of NiSe nanoparticles on g-C3N4 nanosheets for efficient hybrid supercapacitors. Journal of Energy Chemistry (2023).
2. Ni(OH)2 nanosheets grown on porous hybrid g-C3N4/RGO network as high performance supercapacitor electrode. Scientific Reports (2017).
3. Two-step synthesis of millimeter-scale flexible tubular supercapacitors. Communications Chemistry (2020).
4. Protonated C3N4 Nanosheets for Enhanced Energy Storage in Symmetric Supercapacitors through Hydrochloric Acid Treatment. ACS Omega (2024).
5. Copper Oxide Nanoparticles Anchored on Porous Carbon Nitride Nanosheets for Supercapacitor Applications. International Journal of Energy Research (2024).