Facile synthesis of chitosan-derived maillard reaction productions coated CuFeO with abundant oxygen vacancies for higher Fenton-like catalytic performance.

The two shortcomings of the Fenton-like catalyst delafossite-type oxide (CuFeO) lie in its spontaneous agglomeration and deactivation under neutral working pH. To remedy these drawbacks, novel Fenton-like catalyst chitosan-derived maillard reaction productions coated CuFeO with abundant oxygen vacancies (OV-CuFeO@MRPs) was synthesized by hydrothermal method with no extra chemical reducing agent. The systemic characterization illustrated that richer oxygen vacancies and higher particles dispersion of OV-CuFeO@MRPs contributed to better Rhodamine B (RhB) degradation under neutral pH compared to pure CuFeO. Cooper antisite defects in OV-CuFeO@MRPs were evidenced by X-ray powder diffraction (XRD), fourier transform infrared spectrometer (FTIR), Raman spectra and energy dispersive X-ray spectrometer (EDX) linescan. To keep the charge balance, OV-CuFeO@MRPs should form rich oxygen vacancies, which was confirmed by X-ray photoelectron spectroscopy (XPS) and solid-state electron paramagnetic resonance spectrometer (solid-state EPR). Furthermore, the electrochemical impedance spectroscopy (EIS) analysis revealed that oxygen vacancies could improve the electron transfer. Scavenging experiments and electron spin resonance spectroscopy (ESR) analysis demonstrated that OH was main active radical during Fenton-like reaction, and the density functional theory (DFT) calculation verified that the oxygen vacancy could effectively adsorb HO and elongate O-O bond of HO, thus promoting the activation of HO into OH.