Advances in Phenyl-Modified Carbon Nitride: Towards Sustainable Environmental Applications

Addressing the growing pollution and energy demands due to population explosion and industrialization has become the need of the hour for humanity. Researchers have been focused on mitigating these challenges through a sustainable phenomenon called ‘photocatalysis’, where solar light can be utilized to degrade pollutants and obtain useful products. Traditional graphitic carbon nitride (g-C₃N₄) has shown potential in photocatalytic applications due to its chemical stability, visible-light response, and eco-friendly composition. However, limitations such as poor charge separation and limited light absorption have hindered its practical use. To address these challenges, recently researchers have introduced phenyl groups into the carbon nitride framework, which enhanced its optoelectronic properties and broadened its absorption in the visible-light spectrum. Adding phenyl groups extends the conjugated structure of g-C₃N₄, effectively reducing its bandgap and enabling it to capture lower-energy photons. The improved charge carrier dynamics and light absorption make phenyl-modified carbon nitride (PhCN) highly effective for photocatalytic environmental remediation. Despite such ideal enhancements through phenyl modification, PhCN exhibits upgradable light-absorption, stability and charge-recombination characteristics. The thesis aims to study further modifications of PhCN for better photocatalytic activity focalised on organic dye degradation, hydrogen fuel production and viral inactivation with a special focus on visible-light utilization. The study investigates changes in PhCN induced by liquid phase exfoliation, co-catalyst addition, organic-inorganic heterojunction formation and non-metal doping and their potential applications. The study seeks to address existing limitations in PhCN, providing a pathway toward scalable, high-performance photocatalysts which could be cost-effective and bio-friendly.