Aerosol-assisted submicronγ-Fe2O3/C spheres as a promising heterogeneous Fenton-like catalyst for soil and groundwater remediation:Transport,adsorption and catalytic ability

This research reports a novel heterogeneous Fenton-like catalyst which could freely move through the model sediments and easily seize the pollutants in addition to efficiently catalyze H2O2,well suitable for soil and groundwater remediation.Herein,submicron y-Fe2O3/C spheres were synthesized through a facile one-step aerosol-based process.In a series of column tests,these spheres exhibit better transport ability due to their optimal size,conforming to the prediction by the Tufenkji-Elimelech filtration theo ry.Meanwhile,y-Fe2O3/C spheres could act as a strong adsorbent for organic pollutants owing to the presence of carbon,thereby providing a driving force to gather contaminants into their vicinity and facilitating the reaction.In addition,immobilization of y-Fe2O3 nanoparticles into carbon spheres protects iron oxides from aggregation,and thus retains the number of active sites for catalytic decomposition of H2O2.Hence,the system containing the as-prepared y-Fe2O3/C spheres and H2O2 shows the high removal efficiency and degradation efficiency in the remediation of recalcitrant organic contaminants such as methylene blue and sulfamethoxazole.

Co_(a)Sm_(b)O_(x) Catalyst with Excellent Catalytic Performance for NH3 Decomposition

Transition metal-rare earth oxide catalysts had the ability to catalyze ammonia decomposition according to recent years'scientific reports.However,most of those catalysts had their own limitations:the catalytic activity was poor,and/or the active species could not clearly be iden tified.Here we report the Co_(a)Sm_(b)O_(x) catalysts with good dispersi on,con trollable content,and excelle nt catalytic performs nee for amm onia decomposition.The various content catalysts were syn thesized by aerosol-assisted self-assembly approach.These catalysts had high dispersion and great morphology according to the images of the transmission electron microscope(TEM)and the seanning electron microscope(SEM).The temperature-programmed reduction by hydrogen(Hq-TPR)and in-situ X-ray diffraction(XRD)results indicated that the interaction between cobalt oxide and samarium oxide influenced the redox properties of cobalt oxide.Combined with in-situ Raman,we found that Co0 was an active species of the Co_(a)Sm_(b)O_(x) catalysts in ammonia decomposition.Moreover,the temperature-programmed desorption of NH_(3)(NH_(3)-TPD)data illustrated that the addition of Sm was beneficial to the adsorption of NH3.In general,we successfully obtained the Co_(a)Sm_(b)O_(x) catalyst with high activity and good stability.More im-porta ntly,we have identified the structure-function relation ship of catalysts by exploring the active species in the reaction process.