Research on the mechanism of efficient and sustainable degradation of phenolic wastewater by 3D-printed FeNi porous framework

• 3D-printed FeNi alloy frameworks with optimized porous architecture provide abundant active sites and enhanced mass transfer for efficient phenol degradation. • Nickel alloying accelerates electron transfer in the Fe-based catalyst system, significantly boosting the catalytic reaction kinetics. • The monolithic catalyst demonstrates excellent recyclability and stable performance, offering a practical solution to the limitations of conventional powder catalysts in water treatment. The heterogeneous Fenton-like technology has gained attention for its potential in treating refractory organic wastewater. However, traditional nano-catalysts face challenges such as agglomeration, recovery difficulties, and active site deactivation, limiting their practical use. This study proposes a synergistic material-structure design strategy by fabricating a three-dimensional porous FeNi alloy monolithic catalyst via selective laser melting (SLM). Characterization results show that the SLM process yields a dense and uniform solid solution alloy. This structured catalyst exhibits exceptional catalytic activity in the Fenton-like degradation of phenol. Experimental results indicate that at a phenol concentration of 50 mg/L, catalyst dosage of 4 g/L, H 2 O 2 concentration of 5 mmol/L, pH value of 3, and temperature of 50°C, up to 99% of phenol was degraded within 9 minutes. The kinetic reaction constant is measured at 0.31 min⁻¹, with the catalyst being reusable for over 33 cycles. This approach shows great potential in treating phenolic wastewater.