Photocatalytic oxidation of norfloxacin by Zn0.9Fe0.1S supported on Ni-foam under visible light irradiation

Norfloxacin (NOR) is an emerging antibiotics contaminant due to its high resistance to microbial degradation and natural weathering. In this study, Fe-doped ZnS photocatalyst (Zn_0.9Fe_0.1S) was deposited on nickel foam (Ni-foam) to improve photocatalytic activity under visible light irradiation. The mass ratio of Zn_0.9Fe_0.1S and Ni-foam was optimized to be 0.03 g catalyst versus per g Ni-foam (0.03 Zn_0.9Fe_0.1S/Ni-foam), which led to the highest removal rate of 95%. The optimal degradation condition for NOR over 0.03 Zn_0.9Fe_0.1S/Ni-foam was pH at 7.0, initial NOR concentration of 5 mg L^-1, and initial photocatalyst concentration of 11.7 g L^-1, with the highest first-order reaction rate constant of 0.025 min^-1 and mineralization rate of 63.1%. The NOR removal rate on 0.03 Zn_0.9Fe_0.1S/Ni-foam photocatalyst (95%) was approximately four times of that obtained on Zn_0.9Fe_0.1S photocatalyst (25%). The increased photocatalytic performance could be attributed to the function of Ni-foam as excellent electron collectors that provided efficient photoinduced charge separation from Zn_0.9Fe_0.1S. The reactive species responsible for the degradation of NOR were photo-generated holes, hydroxyl radical, and superoxide radicals. Nearly 90% of the photocatalytic efficiency was retained over seven cycles and the released metal ion concentrations were <0.3% of the total mass of photocatalyst, suggesting high stability of the photocatalyst during the photocatalytic reactions. The aqueous/solid mass transfer and intraparticle mass transfer for Zn_0.9Fe_0.1S/Ni-foam were not limiting factors for the degradation of NOR. Therefore the Zn_0.9Fe_0.1S/Ni-foam photocatalyst could be applied in the degradation of hazardous pollutants.

Functionalization of SBA-15 with CeO2 nanoparticles for adsorptive desulfurization: Matters of template P123

Adsorption is one of the most promising methods for desulfurization of transportation fuels, due to the strategy which enables removal of organic sulfur compounds to be conducted at ambient conditions with high efficiency. Adsorbent is the key to the adsorptive performance. Both π complexation and direct sulfur metal bonds are efficient methods for adsorptive desulfurization. For construction of these bonds, it is necessary to introduce active metal species on the support. In this work, Ce(NO3)2 was directly introduced into the as-synthesized SBA-15, and high dispersion of CeO2 nanoparticles was obtained. With the loading content of 12–46 wt%, the particle sizes of the CeO2 NPs are in the range of 4.4–6.3 nm. The good dispersion status of CeO2 nanoparticles is contributed to the template P123 preserved in as-synthesized SBA-15, which provides a confined space for the dispersion of CeO2 nanoparticles. However, the large CeO2 particles (7.0 nm) are formed for the sample originated from template-free SBA-15. We also demonstrate that the adsorptive performance of SBA-15 is enhanced with the modification of CeO2 nanoparticles. Besides, the performances of CeO2 nanoparticle-modified samples stay in step with the dispersion status of the CeO2 nanoparticles.

Modification of as Synthesized SBA-15 with Pt nanoparticles: Nanoconfinement Effects Give a Boost for Hydrogen Storage at Room Temperature

In this work, Pt nanoparticles were incorporated into SBA-15 to prepare the materials for hydrogen spillover adsorption. We provide a direct modification (DM) strategy to improve the content of Pt nanoparticles inside the channels of SBA-15. In this strategy, the Pt precursor was directly incorporated into as synthesized SBA-15 by a solid-state grinding method. The subsequent calcination in air, then H₂/Ar gases was conducted to obtain the resultant materials of PtAS. For the samples of PtAS, Pt nanoparticles up to 5.0 wt% have a high dispersion inside the channels of SBA-15. The size of nanoparticles is in control of 3.7 nm. Although much work so far has focused on modification of SBA-15 with Pt nanoparticles. Here, it is the first time the loading amount of Pt nanoparticles raises up to 5.0 wt%, and the location of the Pt nanoparticles is interior channels of SBA-15. We reveal that the high dispersion behaviors of Pt nanoparticles are ascribed to the nanoconfinement effects provided by as synthesized SBA-15. However, the samples derived from template free SBA-15 (PtCS) show sparsely dispersion of Pt nanoparticles with the size of 7.7 nm. We demonstrate that the PtAS samples show better hydrogen adsorption performance than PtCS.

Recyclable Cu(i)/ZrSBA-15 prepared via a mild vapor-reduction method for efficient thiophene removal from modeled oil

Recyclable Cu(i)/ZrSBA-15 composites prepared via a controllable and effective methanol vapor-reduction method exhibited excellent adsorption capacity for the removal of thiophene (29.9 mg g⁻¹).