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233 Pa, the precursor nuclide of 233 U in the thorium-uranium conversion is prone to reductive deposition in 2LiF-BeF 2 (66 : 34 mol%, FLiBe) molten salt. We explored the adjustment and control of the redox potential of the FLiBe melt to avoid the 233 Pa reduction deposition. The experimental data indicated that the deposited 233 Pa can be completely dissolved and reentered into the molten salt with the addition of oxidant NiF 2 , and the distribution and behaviour of uranium, thorium, neptunium, and most fission products did not have any significant change in the NiF 2 -oxidised FLiBe molten salt, showing the feasibility of this manner to make 233 Pa exist stably in the melt. The effects of NiF 2 -addition on the behaviour of the fission products 95 Nb and 131 I in the FLiBe molten salt were also investigated. It was found that 131 I could be used as a redox indicator to monitor the redox potential of the oxidation-enhanced FLiBe molten salt. All the information drawn from this study could provide significant support for the control and surveillance of the redox potential of the FLiBe molten salt in the upcoming thorium molten salt reactor (TMSR)., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this study, the behavior of fission product iodine released from the melting process of a mixture consisting of UF 4 irradiated with neutrons and 2LiF-BeF 2 (FLiBe) salt was studied. The experiment showed that a large amount of iodine was released immediately during melting and captured by Ni metal foils. The transient release of iodine observed in this experiment is attributed to the redox reaction between the hot atoms of the fission product iodine that cumulated due to long-time irradiation. The effect of the redox status of the molten salt on the transient release of iodine was also investigated. Based on this investigation, it was proposed that the activity ratios of 131 I to salt-seeking fission products in the fuel salt, as an effective diagnostic criterion, may be used for the surveillance of the redox potential of fuel salts in a molten salt reactor., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Distribution and behavior of 233 Pa, essential in the thorium-uranium nuclear fuel cycle, were studied in 2LiF-BeF 2 (66 : 34 mole%, FLiBe) molten salt by γ-ray spectrometry. The experiments showed that 233 Pa deposited slightly on the surface of graphite crucible. The addition of Hastelloy and metallic lithium decreased the 233 Pa specific activity in the salt by 1 to 2 orders of magnitude rapidly. Analysis indicated that reductive deposition of 233 Pa was responsible for the rapid decrease of 233 Pa specific activity in the salt. Additional experiments strongly supported the mechanism of reductive deposition of 233 Pa induced by Hastelloy and metallic lithium. In view of the large deposition of 233 Pa on Hastelloy, the possible influence of fissile nuclide 233 U produced from 233 Pa decay on the operation of thorium-based molten salt reactor was discussed., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

MoS 2 nanosheets were grown on TiO 2 nanotubes by the simple hydrothermal method for the first time. The layer-by-layer growth of MoS 2 nanosheets led to a significant increase in the specific surface area of TiO 2 /MoS 2 burst tube composites compared with TiO 2 burst tubes, a significantly enhanced ability to separate photo-induced carriers, and synergistic adsorption and visible light catalytic activity of dye molecules. The maximum adsorption ( q max ) of MB was 72.46 mg g -1 . In addition, 94.1% of MB could be degraded after 30 minutes of visible light irradiation. The microsurface morphology, structure, chemical composition, element valence and band width of TiO 2 /MoS 2 nanocomposites were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The mechanism of photocatalytic reaction was studied via free radical capture experiments., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Long afterglow phosphors play a significant role in practical applications. However, due to their complex electronic structures, it is difficult to obtain tunable long afterglow phosphors. Herein, a novel long afterglow phosphor, Gd 1.5 Y 1.5 Ga 3 Al 2 O 12 :Tb 3+ , was successfully synthesized. Its detailed structural information was extracted via the Rietveld method, and its corresponding optical properties were further systematically explored via photoluminescence (PL), phosphorescence and thermoluminescence (TL) spectroscopy. Both the photoluminescence and long afterglow properties showed tunable behavior with a variation in the concentration of Tb 3+ . The investigation of the tunability of its photoluminescence and long afterglow properties revealed that the cross-relaxation energy transfer mechanism contributes to its tunable character. Meanwhile, long-lasting phosphorescence could be observed for a few hours by the naked eye in a dark environment after discontinuing the UV irradiation. Due to the potential existence of the photo-excited (Tb 3+ ) + , the defect clusters were proposed, with oxygen vacancies acting as electron trapping centers and (Tb 3+ ) + attracting holes. Finally, an appropriate mechanism for the tunable long afterglow emission was proposed., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

PM 2.5 , due to its small particle size, strong activity, ease of the attachment of toxic substances and long residence time in the atmosphere, has a great impact on human health and daily production. In this work, we have presented patterned nanofiber air filters with high optical transparency, robust mechanical strength and effective PM 2.5 capture capability. Here, to fabricate a transparency air filter by a facile electrospinning method, we chose three kinds of patterned wire meshes with micro-structures as negative receiver substrates and directly electrospun polymer fibers onto the supporting meshes. Compared with randomly oriented nanofibers (named "RO NFs" in this paper) and commercially available facemasks, the patterned air filters showed great mechanical properties, and the water contact angles on their surfaces were about 122-143° (the water contact angle for RO NFs was 81°). In addition, the patterned nanofibers exhibited high porosity (>80%), and their mean pore size was about 0.5838-0.8686 μm (the mean pore size of RO NFs was 0.4374 μm). The results indicate that the transparent patterned air filters have the best PM 2.5 filtration efficiency of 99.99% at a high transmittance of ∼69% under simulated haze pollution., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this study, design and fabrication of novel shape-controllable and aligned nanofibrous membranes with self-cleaning and robust mechanical properties is presented. Smooth and uniform nanofibers can be fabricated by blending polyamide 66 (PA66) and poly (vinyl butyral) (PVB) with a mass ratio of 6/4 during electrospinning. Subsequently, the prepared nanofibrous membranes were placed in a vacuum drying oven at a given temperature (90 °C) for heat treatment, and the morphology of the composite nanofibers was controlled by an external tensile force. It was found that the treatment temperature and external tensile force greatly affected the pore structures and orientation of the nanofiber membranes. In addition, the hydrophobicity, pore structure and mechanical properties of well-aligned nanofibrous membranes are better than those of non heat-treatment nanofibers. Moreover, the PA66/PVB nanofibrous membranes are used as air filters, and show an excellent removal efficiency of up to 99.99% for PM 2.5 ., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Therapeutic drugs remain of great significance for the absorption of wound blood, the closure of wounds and rapid wound healing. Hence, we propose a novel composite nanofiber membrane with the above characteristics as a wound healing material. We utilize the reaction of calcium ion and alginate gel, sodium alginate (SA) and Rana chensinensis skin peptides (RCSPs) extracted from discarded Rana chensinensis skin; these two natural substances were successfully used to prepare composite nanofibers by coaxial electrospinning. The composite nanofibers are named SA@Ca 2+ /RCSPs nanofibers. SA@Ca 2+ /RCSPs nanofibers exhibited that the nanofibers contact with the liquid is unmelted, instead become gel, when compared to nanofibers of does not contain calcium ions, and the absorption rate reached 179.87%. SA@Ca 2+ /RCSPs nanofibers conform to the quasi-first-order dynamics model and the Ritger-Peppas release model. In vivo wound healing experiments showed that the wound-healing rate of SA@Ca 2+ /RCSPs nanofiber-treated wounds was 46.65% and 97.46% on days 5 and 15, respectively. In addition, SA@Ca 2+ /RCSPs nanofibers promoted collagen deposition and enhanced epidermal regeneration. The present study showed that composite nanofibers could quickly undergo hemostasis and effectively promote wound healing., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)