# Humic Acid-Derived Porous Carbon as Peroxymonosulfate Activator for Phenol Removal

## TL;DR

A new carbon material made from humic acid and g-C3N4 efficiently removes phenol from water using peroxymonosulfate activation.

## Contribution

A nitrogen-doped porous carbon material (900-CN) is developed for efficient phenol removal via radical and non-radical pathways.

## Key findings

- 900-CN achieved 100% phenol removal within 60 minutes.
- The material's porous structure and functional groups enhance PMS activation and phenol degradation.
- Phenol degradation occurs through combined radical and non-radical pathways involving •OH, SO4•−, O2•−, and 1O2.

## Abstract

To enable the efficient and environmentally benign treatment of phenol-containing wastewater, a nitrogen-doped porous carbon material (denoted as 900-CN) was synthesized via high-temperature annealing of a composite composed of humic acid (HA) and g-C3N4. The as-prepared materials were characterized, and their catalytic performance in activating peroxymonosulfate (PMS) for phenol degradation was investigated. The results demonstrate that g-C3N4 acts as a layered template; upon high-temperature annealing, it gradually evolves into a highly wrinkled and porous architecture. This morphology substantially increases the specific surface area, thereby facilitating pollutant removal. PMS formed metastable surface complexes on 900-CN, enabling concomitant electron transfer. Concurrently, functional groups on the HA-derived carbon reacted with PMS to generate singlet oxygen (1O2), a highly oxidative species that markedly enhanced phenol degradation. The 900-CN composite achieved complete phenol removal (100%) within 60 min. Variations in reaction temperature (20–50 °C) and initial pH (2–10) exhibited negligible influence on the performance of the 900-CN/PMS system. Reactive species in the 900-CN/PMS/phenol system included •OH, SO4•−, O2•−, and 1O2, indicating that phenol degradation occurred through combined radical and non-radical pathways. These findings highlight the strong potential of 900-CN as a promising catalyst for the treatment of phenolic wastewater.