High-flux rattan biochar microreactor for efficient peroxymonosulfate activation via component-regulated structure engineering

Abstract

Agroforestry waste-derived biochar has attracted wide interest in environmental remediation owing to its resource abundance and structural advantages. However, pristine biochar powders usually exhibit low catalytic activity and encounter challenges in separation and recovery, which limit their large-scale application. Here, we developed a rattan-derived biochar microreactor with a robust monolithic structure and abundant active sites using a facile component-regulation strategy. By tuning the inherent cellulose and lignin composition, we tailored hierarchically porous channels with high surface area, abundant defect-related catalytic sites, and desirable electrical conductivity. Taking peroxymonosulfate (PMS) activation as a model process, the continuous-flow biochar microreactor achieved efficient degradation of tetracycline (TC), methylene blue (MB), and rhodamine B (RhB), with an ultrahigh flux of 2.3 × 10⁴ L/(m²·h) driven by gravity. Coupling with deep mechanism investigation and density functional theory (DFT) simulation, the favorable carbon configurations (e.g., graphitic structures and boundary-like defects) triggered a desirable non-radical dominated pathway in PMS activation, contributing to the impressive catalytic performance. This work not only expands horizons for high value-added utilization of biomass waste but also provides a practical paradigm for designing high-performance biochar microreactors for environmental remediation.