▎ 摘　　要

A series of goethite (Gt)-graphene (rGO) composites (Gt-rGO) having different rGO contents (2%-10%) was biologically prepared under mild conditions with Acidovorax sp. BoFeN1 and exhibited comparable or even higher catalytic efficiencies upon sulfonamides degradation than most known chemically synthesized catalysts. Pseudo-first-order rate constant of sulfanilamide degradation (60 mu M, 0.971 h-1) in the system mediated by GtrGO with the optimal rGO content of 6% was 6.7, 15.4 and 168.1 folds higher than those in the control rGO/ H2O2, Gt/H2O2 and H2O2 systems, respectively. Excellent synergistic catalytic effects between Gt and rGO in GtrGO were identified in four continuous cycles. The Gt-rGO systems exhibited more efficient center dot OH generation, H2O2 decomposition and Fe(II) accumulation rates than the control Gt or rGO systems. Fast Fe(III)/Fe(II) cycling was obtained in the Gt-rGO systems, which might be due to the strong Fe-C coordination and the decrease of rGO aggregation and Gt particle sizes. Additionally, Gt particles in Gt-rGO exposed more defects as active sites for H2O2 activation. High-performance liquid chromatography-mass spectrometer analysis suggested that sulfanilamide was gradually degraded through hydroxylation, C-N cleavage and benzene ring opening. The results provided a new approach for the tailored design of eco-friendly, cost-effective and efficient iron (oxyhydr)oxidesgraphene catalysts for contaminants elimination.