ABSTRACT
In recent years, novel metal halide scintillators have shown great application potential due to their tunable emission wavelength, high X-ray absorption, and high luminescence efficiency. However, poor stability and complex device packaging remain key issues for metal halide scintillators, making it difficult to achieve high-resolution and flexible X-ray imaging applications. To address the above issues, a multiprocessing strategy was introduced to prepare Cs3Cu2I5@PMMA scintillator films for long-term stable application, mainly undergo different annealing treatments to make Cs3Cu2I5 crystals to accurately nucleate and then grow in-situ in the PMMA matrix. Then, a series of characterization results illustrate that the prepared Cs3Cu2I5@PMMA scintillator films have high crystallinity, uniform size, excellent flexibility, high stable photoluminescence (PL) and radioluminescence (RL) performance, and high-resolution X-ray imaging capability. Most importantly, Cs3Cu2I5@PMMA scintillator films can not only provide clear and accurate imaging recognition of objects with different complex structures but also maintain stable X-ray imaging quality within 60 days and can achieve flexible X-ray imaging. Therefore, we have provided an effective strategy for producing high-quality scintillator films to meet the multidimensional needs of a new generation of scintillators.
ABSTRACT
Non-precious metal-based electrocatalysts with high activity and stability for efficient hydrogen evolution reactions are of critical importance for low-cost and large-scale water splitting. In this work, Mo2C-Mo3C2 heteronanowires with significantly enhanced catalytic performance are constructed from an MoAn precursor via an accurate phase transition process. The structure disordering and surface carbon shell of Mo2C-Mo3C2 heteronanowires can be precisely regulated, resulting in an enlarged surface area and a defect-rich catalytic surface. Density functional theory calculations are used to identify the effect of the defective sites and carbon shell on the free energy for hydrogen adsorption in hydrogen evolution. Meanwhile, the synergistic effect between different phases and the introduced lattice defects of Mo2C-Mo3C2 are considered to enhance the HER catalytic performance. The designed catalyst exhibits optimal electrocatalytic activity in both acidic and alkaline media: low overpotentials of 134 and 116 mV at 10 mA cm-2, a small Tafel slope of 64 mV dec-1, and a long-term stability for 5000 cycles. This work will provide new insights into the design of high-efficiency HER catalysts via interfacial engineering at the nanoscale for commercial water splitting.
