Photoelectro-Fenton microreactor integrated with MOF-derived porous α-Fe2O3 film for efficient nanoplastics degradation

The stubborn Nanoplastics (NPs) have provoked serious environment pollution globally and it is urgent to develop efficient technologies to decompose them efficiently. However, the degradation efficiency is still subject to various factors such as the reactor design, catalysts, and reaction pathways. In this work, a photoelectro-Fenton microfluidic reactor was designed to enable the fine-tuning of photoelectro-Fenton reactions by applying both light irradiation and bias potentials to the reaction chamber. To enhance its degradation efficiency and reusability, a MOF-derived porous Fe2O3 material was coated in the reaction chamber. In the experiment, the voltage, illumination, flow rate, and other factors were adjusted to investigate the reactor's properties and optimize the reaction conditions. The study showed α-Fe2O3 catalytic efficiency increased with bias, reaching maximum degradation rate of large than 0.438 %/s at the bias of 1.2 V under the solar light irradiation with the light intensity of 120 mW/cm2, and did not decrease significantly in 4 repeated experiments. Furthermore, the synergistic effect of various oxidation pathways was also revealed. The photoelectro-Fenton microreactor finally showed unprecedented degradability and excellent reusability. The proposed platform is adapted to guide the AOP degradation of NPs, and has potential to be scaled up for industrial NPs removal.