Advancing water purification: The role of copper-carbon nanostructured heterojunctions in pollutant removal

Abstract

Water pollution remains a pressing global challenge, driven by the unchecked release of industrial effluents and agricultural runoff that introduce a broad spectrum of organic and inorganic contaminants into aquatic systems. Among various remediation approaches, such as adsorption, filtration, catalytic oxidation, ion exchange, Fenton-like processes, and photocatalysis, the choice and composition of catalysts critically influence treatment efficiency and sustainability. In this context, copper–carbon nanohybrid heterojunctions (CCNHs) have emerged as promising materials, combining the redox activity of copper-based nanostructures with the high conductivity and surface area of carbonaceous materials. These hybrids enhance charge separation, reduce electron–hole recombination, and exhibit superior adsorption and catalytic properties. This review comprehensively examines recent progress in CCNH-based systems for water purification, focusing on synthesis techniques, heterojunction engineering, defect and surface modification, stabilization strategies, and underlying removal mechanisms. We also highlight advances in pilot-scale applications, discuss challenges such as metal leaching and long-term stability, and propose future directions towards practical deployment of CCNHs in sustainable wastewater treatment technologies.