Hydrogen-Rich 2D Halide Perovskite Scintillators for Fast Neutron Radiography.

A fast neutron has strong penetration ability through dense and bulky objects, which makes it an ideal nondestructive technology for detecting voids, cracks, or other defects inside large equipment. However, the lack of effective fast neutron detection materials limits its application. Perovskites have shown excellent optical properties in many areas, but they are absent from fast neutron detection imaging because they cannot directly absorb fast neutrons and emit luminescence. Here, we demonstrate a hydrogen-rich long-chain organic amine modified two-dimensional (2D) perovskite fast neutron scintillator, Mn-(C18H37NH3)2PbBr4(Mn-STA2PbBr4). Its hydrogen density can reach 9.51 × 1028 m-3, and the photoluminescence quantum yield can reach 58.58%, so it is possible to integrate fast neutron absorption and luminescence into a single compound. More importantly, Mn-STA2PbBr4 can be made into a large-area self-supporting fast neutron scintillator plate with satisfactory spatial resolution (0.5 lp/mm (lp: line pairs)). This strategy provides a simple and promising choice for fast neutron scintillator nondestructive testing.

Large-Area Transparent Antimony-Based Perovskite Glass for High-Resolution X-ray Imaging.

Nonlead low-dimensional halide perovskites attract considerable attention as X-ray scintillators. However, most scintillation screens exhibit pronounced light scattering, which detrimentally reduces the quality of X-ray imaging. Herein, we employed a simple and straightforward solvent-free melt-quenching method to fabricate a large-area zero-dimension (0D) antimony-based perovskite transparent medium, namely (C20H20P)2SbCl5 (C20H20P+ = ethyltriphenylphosphine). The transparency is due to the large steric hindrance of C20H20P+, which hinders the formation of crystals during the quenching process, thus forming a glass with low refractive index and uniform structure. This medium exhibits a high transmittance exceeding 80% in the range of 450-800 nm and shows a large Stokes shift of 245 nm, thereby minimizing light scattering, mitigating self-absorption, and enhancing the clarity of X-ray imaging. Moreover, it exhibits a high radioluminescence light yield of ∼12,535 photons MeV-1 and displays a high X-ray spatial resolution of 30 lp mm-1 owing to its high transparency. This study presents an alternative candidate for achieving high-quality X-ray detection and extends the applicability of transparent perovskite scintillators.

Continuous g-C3N4 layer-coated porous TiO2 fibers with enhanced photocatalytic activity toward H2 evolution and dye degradation.

TiO2/g-C3N4 composite photocatalysts with various merits, including low-cost, non-toxic, and environment friendliness, have potential application for producing clean energy and removing organic pollutants to deal with the global energy shortage and environmental contamination. Coating a continuous g-C3N4 layer on TiO2 fibers to form a core/shell structure that could improve the separation and transit efficiency of photo-induced carriers in photocatalytic reactions is still a challenge. In this work, porous TiO2 (P-TiO2)@g-C3N4 fibers were prepared by a hard template-assisted electrospinning method together with the g-C3N4 precursor in an immersing and calcination process. The continuous g-C3N4 layer was fully packed around the P-TiO2 fibers tightly to form a TiO2@g-C3N4 core/shell composite with a strong TiO2/g-C3N4 heterojunction, which greatly enhanced the separation efficiency of photo-induced electrons and holes. Moreover, the great length-diameter ratio configuration of the fiber catalyst was favorable for the recycling of the catalyst. The P-TiO2@g-C3N4 core/shell composite exhibited a significantly enhanced photocatalytic performance both in H2 generation and dye degradation reactions under visible light irradiation, owing to the specific P-TiO2@g-C3N4 core/shell structure and the high-quality TiO2/g-C3N4 heterojunction in the photocatalyst. This work offers a promising strategy to produce photocatalysts with high efficiency in visible light through a rational structure design.

The proteomics homology of antioxidant peptides extracted from dry-cured Xuanwei and Jinhua ham.

The objective of this study was to investigate the antioxidant activity and the homology of peptides extracted from dry-cured Xuanwei and Jinhua ham. The antioxidant activity of crude peptides was assessed by ORAC and ABTS assays and the scavenging effects on DPPH and O2- free radicals. LC-ESI-Q-TOF-MS/MS was used to analyze the peptide composition. Based on the identified peptides, homologous proteins were matched by the Peaks software. Overall, 243 and 213 peptides were identified with their parent proteins in Xuanwei and Jinhua dry-cured hams. Based on the ORAC and TEAC values, XHP showed higher antioxidant ability than JHP (P < 0.05). After further purification by G-15 chromatography, the results indicate that the oligopeptides with less than 1000 Da had greater antioxidant activity than the other two fractions. Homology-based proteomics showed that the majority of peptides originated from myosin which accounted for 26% in XHP and 32% in JHP respectively.