Fe/Mo2C loaded on reed straw cellulose biochar as a Fenton-like catalyst for the degradation of acetaminophen over a wide pH range.

The Fenton reaction is renowned for its high efficiency and well-established operational framework in medicinal chemistry, and environmental remediation. In this study, a novel pH-adaptive Fenton-like catalyst was developed by anchoring Fe-doped molybdenum carbide (Mo2C) nanoparticles onto reed straw cellulose biochar via a two-step calcination process, yielding a series of composites designated as Fex@Mo2C/BC (x = 1, 2, 3). Among these, the Fe1@Mo2C/BC catalyst demonstrated exceptional performance in the presence of H2O2, achieving complete degradation (100 %) of 20 mg/L acetaminophen (ACE) within 30 min. Notably, the catalyst maintained high degradation efficiency across a wide pH range (pH 2-10), retaining 74.27 % activity after four reuse cycles, underscoring its robustness and adaptability. Mechanistic investigations revealed that Mo2C played a pivotal role in promoting the reduction of Fe3+ to Fe2+, thereby sustaining the Fenton-like catalytic cycle. Simultaneously, the in situ generation of H+ helped preserve an acidic microenvironment, effectively suppressing the precipitation of inactive Fe(OH)3 species. The integration of biochar further enhanced the structural stability of the catalyst and significantly reduced iron ion leaching. The Quenching experiments identified superoxide radicals (O2•-) as the primary reactive oxygen species responsible for ACE degradation. Additionally, the active sites and degradation pathways of ACE were elucidated through density functional theory (DFT) calculations and high-performance liquid chromatography-mass spectrometry (LC-MS) analysis. Overall, this work presents a compelling strategy for designing high-efficiency, pH-tolerant Fenton-like catalysts, offering both theoretical insights and practical solutions for wastewater treatment and the valorization of agricultural biomass.