Pharmaceutical pollutants in water: Carbon nanotube–photocatalyst composites as a path forward

Pharmaceutical pollutants (PhPs) are emerging pollutants in aquatic environments that pose significant risks to ecosystems and public health by promoting antibiotic resistance and bioaccumulation. Owing to their chemical stability and resistance to conventional treatments, these pollutants highlight the urgent need for advanced water treatment technologies. Carbon nanotube-photocatalyst composites (CNTs-PCs) represent a transformative approach, leveraging the exceptional properties of CNTs to enhance the photocatalytic degradation of PhPs. CNTs improve light absorption, increase surface area, and facilitate electron hole separation, making them integral to advancing heterogeneous photocatalysis. This review examines the current state of CNTs-PC, focusing on their mechanisms, performance under various conditions, and barriers to real-world application. Key challenges include interference from natural organic matter, heavy metals, and fluctuating water chemistry, which hinder efficiency. Strategies to overcome these challenges include optimizing CNT loading, refining synthesis methods, and enhancing the stability and reusability of CNTs-PC. Moreover, integrating CNTs-PC with hybrid technologies, such as other advanced oxidation processes, can improve pollutant degradation and applicability. Emphasizing scalability and cost-effectiveness, this review identifies critical gaps in current research and provides actionable insights for bridging the gap between laboratory successes and practical deployment. By addressing economic constraints, material durability, and operational efficiency, CNTs-PCs offer a promising pathway to mitigate pharmaceutical pollution. These findings underscore the importance of advancing CNTs-PCs as sustainable solutions for environmental remediation, providing a comprehensive framework for their future development and implementation in large-scale water treatment systems. • CNTs-PC enhance light absorption and electron-hole separation efficiency. • Optimized CNT ratios crucial for maximizing photocatalytic performance. • Scalability and economic viability remain key challenges for large-scale usage. • Selective degradation and valuable by-product generation require further research. • AI and computational modeling can optimize CNTs-PC design and operation.