Edge interface microenvironment regulation of CoOOH/commercial activated carbon nano-hybrids enabling PMS activation for degrading ciprofloxacin.

Peroxymonosulfate (PMS) is widely employed to generate oxygen-containing reactive species for ciprofloxacin (CIP) degradation. Herein, cobalt oxyhydroxide @activated carbon (CoOOH@AC) was synthesized via a wet chemical sedimentation method to activate PMS for degradation of CIP. The result suggested AC can support the vertical growth of CoOOH nanosheets to expose high-activity Co-contained edges, possessing efficient PMS activation and degradation activity and catalytic stability. In the presence of 3.0 mg of optimal CoOOH@AC and 2 mM PMS, 96.8 % of CIP was degraded within 10 min, approximately 11.6 and 9.97 times greater than those of CoOOH/PMS and AC/PMS systems. Notably, it was disclosed that the optimal CoOOH@AC/PMS system still exhibited efficient catalytic performance in a wide pH range, different organics and common co-existing ions. Quenching experiments and electron paramagnetic resonance indicated that both radical and non-radical processes contributed to the degradation of CIP, with 1O2 and direct electron transfer accounting for the non-radical pathway and SO4•- and •OH serving as the main radical active species. Finally, possible CIP degradation pathways were proposed based on high-performance liquid chromatography-mass spectrometry. This study provided an alternate method for wastewater treatment based on PMS catalyzed by cobalt-based hydroxide.

Preparation of Ni-Doped CeFeO3 by Microwave Process and Its Visible-Light Photocatalytic Activity.

Using Ce(NO3)3· 6H2O, Fe(NO3)3· 9H2O and Ni(NO3)3· 6H2O as the main raw materials, nano Ni-doped CeFeO3 was prepared by the microwave method for the first time. The Ni-doped CeFeO3samples were characterized by XRD, SEM, DRS and EDS. The results show that Ni-doped CeFeO3exhibits a perovskite structure (ABO3), and contains nanosheets less than 10 nm thick. The prepared nanosheets have an optical band gap of 1.93 eV. The effect of different doping amounts on the photocatalytic properties of Ni-doped CeFeO3 was studied under visible light, using methyl-orange. When the concentration of the methyl-orange solution was 10 mg/L, and the illumination time allowed for photocatalysis was 90 min, the degradation rate rose to nearly 98%. Moreover, Ni-doped CeFeO3 has a higher photocatalytic activity than pure CeFeO3 powder, making it suitable for a broad range of applications.

Microwave Synthesis of Nanoparticulate SmFeO3 and Its Characterization.

Single phase perovskite SmFeO3 nanoparticles were synthesized using a simple microwave method using Fe(NO3)3· 9H2O and Sm(NO³)³ · 6H2O. The resulting samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area measurement, UV-visible diffuse reflectance spectroscopy (DRS) and Fourier transform infrared spectroscopy (FTIR). XRD and SEM results demonstrate the successful synthesis of nanocrystalline SmFeO3 and show an average grain size of 50-60 nm. The single phase structure and optical properties of SmFeO3 were maintained after calcination at 1000 °C. The prepared nanocrystalline SmFeO3 displays excellent thermal stability and strong visible-light absorption, with an absorption onset of 540 nm or so. The photocatalytic experiment involving the decomposition of methyl orange under visible-light irradiation shows the high photocatalytic activity of the nanoparticles.

Synthesis and characterization of gold cubic nanoshells using water-soluble GeO2templates.

Size-tunable GeO2 nanocubes were initially prepared by a modified sono-assisted reverse micelle method and then functionalized with an amino-terminated silanizing agent. Subsequently, gold decorated GeO2 nanocomposites were prepared at pH ≈ 7 and 80 °C. It was found that well-dispersed gold nanoparticles on GeO2 nanocubes could be obtained only if gold salt is abundant to favor simultaneous, homogeneous nucleation of gold particles. Additional gold ions were reduced onto these attached 'seed' particles accompanied by synchronous dissolution of water-soluble GeO2 cores, resulting in gold hollow cubic shells. The GeO2 nanocubes and Au/GeO2 nanocomposites as well as gold hollow cubic shells were characterized by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and UV-visible spectroscopy. In particular, gold hollow cubic shells feature a plasmon resonance peak at above 900 nm, which renders it quite promising in biochemical applications.