Intrinsically morphological effect of perovskite BaTiO3 boosting piezocatalytic uranium extraction efficiency and mechanism investigation.

Developing a convenient, efficient and eco-friendly approach for the recovery of U(VI) ion is a key measure to solve the environmental problems arising from the utilization of nuclear energy. Herein, the high efficiency of uranium extraction is realized by the piezo property of perovskite BaTiO3, revealing the intrinsically morphological engineering effect on the piezocatalytic performance. Especially, BaTiO3 nanowires (BTO NWs) exhibit not only an excellent piezocatalytic activity with U(VI) extraction rate of 96.8% in a UO2(NO3)2 aqueous solution compared to 71.3% of BaTiO3 nanoparticles (BTO NPs), but also a promising piezocatalyst for U extraction in a real U-mining wastewater with various pH ranges. Piezo response force microscopy and finite elemental simulation show that the piezo response of BTO NWs is much higher than BTO NPs. Additionally, some factors (pH, various ions, different powers) are explored on piezocatalytic efficiency for U(VI) extraction. The results from electron spin resonance and the charge/radical capture experiments confirm that the active species (e-, •O2-, •OH) stemmed from the piezo induction of BTO NWs and BTO NPs in the piezocatalytic U(VI) reduction process. The present work reveals the structure-performance correlation during piezocatalysis and highlights the crucial role of piezocatalysis in dealing with environmental problems.

Temperature Tolerance Electric Cell-Substrate Impedance Sensing for Joint Assessment of Cell Viability and Vitality.

Evaluation of the cell health status is critical for drug screening and cell physiological activity investigations. The existing cell health assessment methods are solely devoted to the study of cell vitality or viability, leading to an incomplete evaluation. Herein, we report a convenient and robust method for the joint assessment of cell viability and vitality based on electric cell-substrate impedance sensing (ECIS) supplied with an environmental temperature control. The static value of electric cell-substrate impedance reflects the survival rate of cells, while the temperature tolerance of cells demonstrates the cell vitality. It was found that the cell vitality evaluated by the temperature tolerance of cells was independent of the initial cell numbers, rendering the proposed method easy to utilize in various applications. We compared the temperature tolerance ECIS method with the traditional trypan blue staining method, the methyl thiazolyl tetrazolium assay, and the direct impedance sensing method for joint evaluation of cell viability and vitality in drug screening. The temperature tolerance ECIS method showed comparable results but with a simpler protocol, faster results, and less dependence on the sample conditions. By providing both information on cell viability and cell vitality, the proposed temperature tolerance ECIS method would pave the way in building a simple and robust sensing system for cell health evaluation.