Platinum-tin oxide core-shell catalysts for efficient electro-oxidation of ethanol.

Platinum-tin (Pt/Sn) binary nanoparticles are active electrocatalysts for the ethanol oxidation reaction (EOR), but inactive for splitting the C-C bond of ethanol to CO2. Here we studied detailed structure properties of Pt/Sn catalysts for the EOR, especially CO2 generation in situ using a CO2 microelectrode. We found that composition and crystalline structure of the tin element played important roles in the CO2 generation: non-alloyed Pt46-(SnO2)54 core-shell particles demonstrated a strong capability for C-C bond breaking of ethanol than pure Pt and intermetallic Pt/Sn, showing 4.1 times higher CO2 peak partial pressure generated from EOR than commercial Pt/C.

A comprehensive study of the colloidal properties, biocompatibility, and synergistic antioxidant actions of Antarctic krill phospholipids.

Excipient selection is crucial to address the oxidation and solubility challenges of bioactive substances, impacting their safety and efficacy. AKPL, a novel ω-3 polyunsaturated fatty acids (PUFAs) esterified phospholipid derived from Antarctic krill, demonstrates unique antioxidant capabilities and synergistic effects. It exhibits pronounced surface activity and electronegativity at physiological pH, as evidenced by a critical micelle concentration (CMC) of 0.15 g/L and ζ-potential of -49.9 mV. In aqueous environments, AKPL self-assembles into liposomal structures, offering high biocompatibility and promoting cell proliferation. Its polyunsaturated bond-rich structure provides additional oxidation sites, imparting antioxidant properties superior to other phospholipids like DSPC and DOPC. Additionally, AKPL augments the efficacy of lipophilic antioxidants, such as alpha-tocopherol and curcumin, in aqueous media through both intermolecular and intramolecular interactions. In sum, AKPL emerges as an innovative unsaturated phospholipid, offering new strategies for encapsulating and delivering oxygen-sensitive agents.

A new dental CBCT metal artifact reduction method based on a dual-domain processing framework.

Objective.Cone beam computed tomography (CBCT) has been wildly used in clinical treatment of dental diseases. However, patients often have metallic implants in mouth, which will lead to severe metal artifacts in the reconstructed images. To reduce metal artifacts in dental CBCT images, which have a larger amount of data and a limited field of view compared to computed tomography images, a new dental CBCT metal artifact reduction method based on a projection correction and a convolutional neural network (CNN) based image post-processing model is proposed in this paper. Approach.The proposed method consists of three stages: (1) volume reconstruction and metal segmentation in the image domain, using the forward projection to get the metal masks in the projection domain; (2) linear interpolation in the projection domain and reconstruction to build a linear interpolation (LI) corrected volume; (3) take the LI corrected volume as prior and perform the prior based beam hardening correction in the projection domain, and (4) combine the constructed projection corrected volume and LI-volume slice-by-slice in the image domain by two concatenated U-Net based models (CNN1 and CNN2). Simulated and clinical dental CBCT cases are used to evaluate the proposed method. The normalized root means square difference (NRMSD) and the structural similarity index (SSIM) are used for the quantitative evaluation of the method.Main results.The proposed method outperforms the frequency domain fusion method (FS-MAR) and a state-of-art CNN based method on the simulated dataset and yields the best NRMSD and SSIM of 4.0196 and 0.9924, respectively. Visual results on both simulated and clinical images also illustrate that the proposed method can effectively reduce metal artifacts.Significance. This study demonstrated that the proposed dual-domain processing framework is suitable for metal artifact reduction in dental CBCT images.

Superelastic and superhydrophobic bacterial cellulose/silica aerogels with hierarchical cellular structure for oil absorption and recovery.

Bacterial cellulose aerogels/silica aerogels (BCAs/SAs) are prepared using three-dimensional self-assembled BC skeleton as reinforcement and methyltriethoxysilane derived silica aerogels as filler through vacuum infiltration and freeze drying. The BCAs/SAs possess a hierarchical cellular structure giving them superelasticity and recyclable compressibility. The BCAs/SAs can bear a compressive strain up to 80% and recover their original shapes after the release of the stress. The BCAs/SAs exhibit super-hydrophobicity with a contact angle of 152° and super-oleophilicity resulting from the methyl groups on the surface of silica aerogel filler. This endows the BCAs/SAs outstanding oil absorbing capability with the quality factor Q from 8 to 14 for organic solvents and oils. Moreover, the absorbed oil can be retrieved by mechanically squeezed with a recovery of 88% related to the superelastic ability of the composites. In addition, the oil absorbing of BS/SAs could be well maintained with the quality factor Q about 11 for gasoline after harsh conditional treatment down to -200 °C and up to 300 °C. Such outstanding elastic and oleophilic properties make the BC/SAs tremendous potential for applications of oil absorbing, recovery and oil-water separation.

A General Method for Multimetallic Platinum Alloy Nanowires as Highly Active and Stable Oxygen Reduction Catalysts.

An unconventional class of high-performance Pt alloy multimetallic nanowires (NWs) is produced by a general method. The obtained PtNi NWs exhibit amazingly specific and mass oxygen reduction reaction (ORR) activities with improvement factors of 51.1 and 34.6 over commercial Pt/C catalysts, respectively, and are also stable in ORR conditions, making them among the most efficient electrocatalysts for ORR.

Fabrication of electric papers of graphene nanosheet shelled cellulose fibres by dispersion and infiltration as flexible electrodes for energy storage.

An electrically conductive and electrochemically active composite paper of graphene nanosheet (GNS) coated cellulose fibres was fabricated via a simple paper-making process of dispersing chemically synthesized GNS into a cellulose pulp, followed by infiltration. The GNS nanosheet was deposited onto the cellulose fibers, forming a coating, during infiltration. It forms a continuous network through a bridge of interconnected cellulose fibres at small GNS loadings (3.2 wt%). The GNS/cellulose paper is as flexible and mechanically tough as the pure cellulose paper. The electrical measurements show the composite paper has a sheet resistance of 1063 Ω□(-1) and a conductivity of 11.6 S m(-1). The application of the composite paper as a flexible double layer supercapacitor in an organic electrolyte (LiPF(6)) displays a high capacity of 252 F g(-1) at a current density of 1 A g(-1) with respect to GNS. Moreover, the paper can be used as the anode in a lithium battery, showing distinct charge and discharge performances. The simple process for synthesising the GNS functionalized cellulose papers is attractive for the development of high performance papers for electrical, electrochemical and multifunctional applications.