Carbon redirection via tunable Fenton-like reactions under nanoconfinement toward sustainable water treatment

Abstract

The ongoing pattern shift in water treatment from pollution control to energy recovery challenges the energy-intensive chemical oxidation processes that have been developed for over a century. Redirecting the pathways of carbon evolution from molecular fragmentation to polymerization is critical for energy harvesting during chemical oxidation, yet the regulation means remain to be exploited. Herein, by confining the widely-studied oxidation system—Mn3O4 catalytic activation of peroxymonosulfate—inside amorphous carbon nanotubes (ACNTs), we demonstrate that the pathways of contaminant conversion can be readily modulated by spatial nanoconfinement. Reducing the pore size of ACNTs from 120 to 20 nm monotonously improves the pathway selectivity toward oligomers, with the yield one order of magnitude higher under 20-nm nanoconfinement than in bulk. The interactions of Mn3O4 with ACNTs, reactant enrichment, and pH lowering under nanoconfinement are evidenced to collectively account for the enhanced selectivity toward polymerization. This work provides an adaptive paradigm for carbon redirection in a variety of catalytic oxidation processes toward energy harvesting and sustainable water purification.

Direct Electron Transfer-Driven Nontoxic Oligomeric Deposition of Sulfonamide Antibiotics onto Carbon Materials for In Situ Water Remediation

“…Moreover, the complex matrix present in natural water can consume massive ROS during pollutant mineralization, resulting in oxidant wastage. , This can escalate economic costs and also elevate salinity and microbial death, posing environmental risks such as aquatic ecosystem destruction and human health hazards . Additionally, the CO 2 generated from mineralization increases the emission of greenhouse gases. , Recent studies of advanced oxidation processes (AOPs) have highlighted polymerization techniques for phenolic organic compound removal. − Phenolic substances can be rapidly coupled by generating organic radicals from reactions, achieving the polymerization removal of phenolic substances. This approach requires less oxidant input and avoids CO 2 emissions, suggesting a promising treatment modality.…”

“…Despite the promise of pollutant removal through polymerization reactions, research on its application in ISCO remains in its early stages with its potential and mechanisms not yet fully understood. Previous studies have predominantly focused on polymerizing simpler phenolic compounds such as phenol, ,− chlorophenol, , bromophenol, and bisphenol A, with less attention given to structurally complex SAs. The feasibility of removing SAs via polymerization pathways and the associated reaction mechanisms remain unclear, necessitating further exploration.…”