Harnessing non-noble metal-doped carbon composites for remediation of phthalate esters contaminated water systems

Abstract

Conventional noble metal catalysts exhibit excellent electrical conductivity and catalytic activity; however, their high cost, moderate cyclability, and limited availability render them economically impractical for widespread applications. To solve these problems, non-noble metal-doped carbon (Met@C) composites are highly active, economical, structurally and chemically stable, and have been recommended as next-generation materials for removal of emerging contaminants, such as phthalate esters (PAEs). PAEs are commonly used as plasticizers and categorized as low- and high-molecular weight PAEs to understand their differential acute and chronic toxicological profiles. However, they may leach from plastic products, raising environmental concerns regarding their use. A review of PAEs-Met@C interactions will be helpful for targeted design of Met@C for effective PAEs removal. This paper reviews Met@C and its synthesis and environmental applications, specifically PAEs removal from water via adsorption, activation oxidation, photocatalysis, Fenton/Fenton-like processes, and coupled treatment processes and the mechanisms overlaid. It also discusses factors influencing the performance of Met@C for PAEs removal and degradation. To provide mechanistic insights into degradation kinetics and mechanisms of AOPs for PAEs removal, it describes pseudo-1^st-order and 2^nd-order rate constants and radical and nonradical species along with density functional theory and molecular dynamics simulations. To address stability, durability, and scalability of Met@C, it thoroughly explores metal leaching, regeneration, and real-world applications of Met@C for PAEs removal. Before conclusions, it overviews perspectives, future challenges, and opportunities for PAEs removal by Met@C. Overall, this review provides a basis for Met@C to solve technique problems in remediation of PAEs contaminated water systems.