Efficient removal of dyes using activated carbon fibers coupled with 8-hydroxyquinoline ferric as a reusable Fenton-like catalyst

• Developing a novel heterogeneous Fenton-like catalyst of QuFe@ACFs.
• Presenting a remarkable pH-tolerant performance at a wide pH range.
• Exhibiting the excellent sustained catalytic ability and reusable capability.

The development of a pH-tolerant Fenton-like catalyst is an active and challenging project in water treatment. In this study, activated carbon fibers (ACFs) supported 8-hydroxyquinoline ferric (QuFe) has been reported as a heterogeneous Fenton-like catalyst (QuFe@ACFs) for efficient removal of dyes. The catalyst possessed remarkable catalytic performance across a wide range of pH values (3–9). Moreover, it also presented excellent sustained catalytic ability and regeneration capability in the experiments, causing reducing secondary contamination. Importantly, with the introduction of ACFs, QuFe@ACFs exhibited a greatly enhanced catalytic activity in comparison with bare QuFe. The hydroxyl radicals (OH) are confirmed as the active species in QuFe@ACFs/H2O2 system by the use of electron paramagnetic resonance (EPR) and fluorescence spectra. In addition, the central composite design (CCD) matrix and response surface methodology (RSM) were applied in designing the experiments for evaluating the interactive effects of temperature, pH, initial dye concentration and catalyst dosage. This study not only opens a novel avenue for designing pH-tolerant heterogeneous Fenton-like catalyst, but also provides a viable process for efficient elimination of dyes effluent.