Graphite-phase carbon nitride composites: Pioneering advancements and future prospects in capacitive desalination

Amidst the escalating global freshwater crisis driven by scarcity and pollution, capacitive deionization (CDI) has gained prominence as a low-energy solution for desalination, particularly for low-concentration saline solution. Conventional carbon-based electrodes, however, suffer from limited salt adsorption capacity (<15 mg g^-1). Graphitic carbon nitride (g-C₃N₄) has emerged as a promising CDI electrode material due to its tunable electronic structure, exceptional chemical stability, and cost-effective synthesis. This review systematically summarizes breakthroughs in g-C₃N₄-based composites, focusing on innovative strategies such as transition metal doping (e.g., MnO₂/g-C₃N₄ heterojunctions) and non-metal functionalization (e.g., sulfur-doped g-C₃N₄). These approaches enhance conductivity and achieve record salt adsorption capacities (SACs) up to 100.3 mg g^-1, outperforming traditional materials. By addressing challenges in scalability and interfacial charge transfer, we highlight the potential of g-C₃N₄ composites to enable energy-efficient, high-throughput desalination technologies for sustainable water resource management.