Study On The Catalysts With Dual Reaction Centers In The Heterogeneous Fenton-like Reaction Of Pollutant Degradation

The increasingly serious water shortage and water environmental pollution have further intensified the water crisis in China.Moreover,pharmaceuticals and personal care products(PPCPs)are widely detected in environment,and could cause a threat to human health.Therefore,it is urgent to destroy refractory micro-pollutants in water bodies.Advanced oxidation process(AOPs)are one of effective techonologies to remove PPCPs.The low reduction rate of M(n+m)+/Mn+and low utilization of H2O2 limit the appliaction of the heterogeneous Fenton-like reaction.In this thesis,a highly efficient and dual-reaction-center heterogeneous catalysts are studied in the Fenton-like reaction,according to the theoretical basis of dual-reaction-center,and the chemical control of the surface structure of catalytic materials.Fe and Mo metal with large difference of electronegativity were selected,and the Fe-MoS2/rGO catalyst was synthesized by solvothermal method.The catalyst showed the better catalytic performance in the heterogeneous Fenton-like reaction for the degradation of sulfamethazine(SMT),compared with rGO,Fe/rGO and MoS2/rGO catalysts.The preparation methods of the catalyst and the operating conditions in the Fenton-like reaction were optimized.The results showed that the SMT removal reached to 82%after 45min over the Fe-MoS2/rGO catalyst udner the mild reaction conditions([SMT]0=20 mg/L,pH=6.5,[H2O2]0=20 mM,[Catalyst]=0.2 g/L,T=25℃),and the low metal leaching was obtained in the reaction.The results indicated that the Fe-MoS2/rGO catalyst had good catalytic performance and stability.The Cu-Bi/SiO2 catalyst with dual reaction center was synthesized by a hydrothermal method.When the Cu loading was 1.5wt.%and the Cu/Bi molar ratio was 5/3,the Cu-Bi/SiO2 catalyst exhibited good performance in the Fenton-like reaction.The Cu-Bi/SiO2 catalyst showed the different removal in the reaction of various pollutants(Phenytoin sodium,Bisphenol A,4-Chlorophenol,sulfamethazine,Ibuprofen)at the mild operating conditions([Pollutans]0=10 mg/L,[H2O2]0=12 mM,[Catalyst]=0.8 g/L,T=25℃)under neutral pH.The degradation performance of pollutants has a certain relationship with their ionization potential(IP).The catalyst was characterizated by X-ray diffraction(XRD),Scanning electron microscope(SEM)and X-ray photoelectron spectroscopy(XPS).The catalyst successfully constructed metal chemical bonds and the dual reaction centers,promoted electron transfer,and had good catalytic performance in heterogeneous Fenton-like reaction.In the radical experiments,the main reactive oxygen species(ROS)produced were HO2·/O2·-and 1O2 in the Fenton-like reaction over the prepared Fe-MoS2/rGO catalyst and the Cu-Bi/SiO2 catalyst.