Covalent organic frameworks doped with manganese-metal organic framework for peroxymonosulfate activation

A novel N, O modified Mn_(3)O_(4)@porous carbon catalyst(NOC-Mn_(3)O_(4)) was prepared by direct carbonization using the manganese-metal organic framework(Mn-MOF) and covalent organic framework(COF) as precursors to activate peroxymonosulfate(PMS) for the degradation of bisphenol A(BPA) and rhodamine B(Rh B). Benefiting from the N and O co-doping of COF, larger specific surface area, faster electron transfer and Mn cycling, the optimum 1NOC-Mn_(3)O_(4)could significantly improve the degradation performance of BPA and Rh B(92.1% and 96.9% within 30 min) as compared to C-Mn_(3)O_(4)without COF doping. In addition, 1NOC-Mn_(3)O_(4) showed good reusability and strong anti-interference ability. Radical quenching experiments, X-ray photoelectron spectroscopy(XPS), Electron paramagnetic resonance spectrometer(EPR) and electrochemical tests showed that the 1NOC-Mn_(3)O_(4)/PMS system degraded BPA and Rh B by both radical and non-radical pathways. Moreover, the possible degradation pathways of BPA and Rh B were proposed by liquid chromatography-mass spectrometry(LC-MS). Except for that, the toxicity of BPA, Rh B and their intermediates were evaluated. This study opens up a new prospect for the design of COF-doped PMS catalysts.

Fabrication of NiCoP decorated TiO_(2)/polypyrrole nanocomposites for the effective photocatalytic degradation of tetracycline

Due to the massive discharge of antibiotics in water,it is an urgent matter to remove antibiotics from waste water.The photocatalysts with high stability and activity have attracted extensive attention from researchers.By an in-situ polymerization method,polypyrrole(PPy)was modified on the surface of TiO_(2)(named as TiO_(2)/PPy).By one-step reduction method,NiCoP was grafted on the surface of TiO_(2)/PPy(named as TiO_(2)/PPy/NiCoP)to synthesize the photocatalyst of TiO_(2)/PPy/NiCoP for degradation of tetra-cycline(TC)antibiotic.The characterization results revealed that NiCoP was deposited on the surface of TiO_(2)/PPy successfully.The photocatalytic experiment results illustrated that 83.2%of TC could be de-graded at natural pH with 20 mg of TiO_(2)/PPy/NiCoP in 50 mL of TC solution(10 mg/L)under visible light irradiation.The high catalytic activity is attributed to the attachment of NiCoP on the surface of TiO_(2)/PPy which can enlarge the light response range of TiO_(2)effectively.Scavenger studies revealed that the degra-dation of TC was dominated by•O_(2)−and h+.The photodegradation efficiency of TC with TiO_(2)/PPy/NiCoP still reached over 74%after 5 consecutive cycles,indicating the potential applications in practical wastew-ater.