Evaluation of polycrystalline cerium oxide electrodes for electrochemiluminescent detection of sarcosine

Prostate cancer (PCa) is widely spread in male population, especially over 65 years. Currently used medical methods of PCa diagnosis often lead to false-positive results thus new non-invasive methods for PCa detection, such as urine tests for cancer metabolites, are actively studied. Herein, nanostructured polycrystalline cerium oxide thin films (CeO2/GC) prepared by magnetron sputtering on a glassy carbon substrate are tested for electrochemiluminescent (ECL) detection of sar-cosine exploiting the oxidative-reduction mechanism using Ru(bpy)32+ as luminophore. Non-functionalized CeO2/GC electrodes revealed a higher ECL signal stability compared to bare glassy carbon electrodes. Moreover, CeO2/GC electrodes were successfully applied for rapid and sensitive detection of different sarcosine con-centrations ranging from 50 to 5000 mu M. These results open new possibilities for developing sensing platforms for sarcosine detection based on the CeO2/GC working electrode via surface modification and functionalization, aiming to further investigate and improve their sensitivity and selectivity

An electrochemical cell for in operando small angle X-ray scattering and X-ray absorption spectroscopy analyses for proton exchange membrane fuel cells and electrolyzers

The effectiveness of the transition from fossil fuels-based energy systems, to (more) sustainable ones, can be strongly supported by establishing hydrogen-based economies in the so called hard-to-abate sectors (as for example heavy industry or maritime), where green hydrogen, produced via water electrolysis powered by renewable energy sources, is further processed by means of fuel cells to produce electrical energy. Producing efficient and cost-effective fuel cell systems and water electrolyzers is then fundamental for promoting the spread of green hydrogen generation and use. In this scenario, fuel cell technology remarkably improved in the last decades, promoting Proton Exchange Membrane Fuel Cells (PEMFCs) use in the automotive and in transportation sectors. Nonetheless, the complex architecture of fuel cells and electrolyzers, still slows down the research and development required for improving their efficiency and lifetime, and contemporary reducing their production costs, which are still strongly bounded to the cost of catalyst materials (Wang et al., 2020). Important achievements in optimizing fuel cell architecture and/or catalyst loading, were obtained thanks to analysis carried out in operando conditions, which allowed to increase the depth of knowledge about catalyst degradation phenomena (Shan et al., 2016). Moreover, important phenomena characterizing fuel cell operation and degradation were revealed by in operando analysis carried out at synchrotron facilities, or using neutrons as a probe. In particular, Small Angle X-ray Scattering (SAXS) was used for highlighting catalyst morphological evolution (Martens et al., 2022; Povia et al., 2018) (also supported by former studies on catalyst model systems (Bogar et al., 2021; Ruge et al., 2017)), while X-Ray Absorption Spectroscopy (XAS

Design of nano-structured Cu loaded CeO2 catalyst for CO oxidation

For CuO-CeO2 catalyst ultra fine particle CeO2catalyst with large specific surface area has been requested from the view point of CO oxidation action. Manufacturing of CeO2 nanopowder by means of the soft chemical method is examined. CeO2 nanopowder is synthesized by the ammonia carbonate coprecipitation method, thenCuO nanotubes are mounted on the powder by the lower temperature calcinations to fabricate nanostructure Cu mounting CeO2 catalyst . TEM,SEM and XRD analysis result of the structure of this catalyst are shown. The organization of developed nanosize Cu on CeO2 is confirmed. This kind of catalyst seems to be a powerful oxidation catalyst

Room Temperature Atomic Layer Deposited Al2O3 Improves the Efficiency of Perovskite Solar Cells over Time

Electrical characterisation of perovskite solar cells consisting of room amp; 8208;temperature atomic amp; 8208;layer amp; 8208;deposited aluminium oxide RT amp; 8208;ALD amp; 8208;Al2O3 film on top of a methyl ammonium lead triiodide CH3NH3PbI3 absorber showed excellent stability of the power conversion efficiency PCE over a long time. Under the same environmental conditions for 355 amp; 8197;d , the average PCE of solar cells without the ALD layer decreased from 13.6 to 9.6 amp; 8201; , whereas that of solar cells containing 9 ALD cycles of depositing RT amp; 8208;ALD amp; 8208;Al2O3 on top of CH3NH3PbI3 increased from 9.4 to 10.8 amp; 8201; . Spectromicroscopic investigations of the ALD perovskite interface revealed that the maximum PCE with the ALD layer is obtained when the so amp; 8208;called perovskite cleaning process induced by ALD precursors is complete. The PCE enhancement over time is probably related to a self amp; 8208;healing process induced by the RT amp; 8208;ALD amp; 8208;Al2O3 film. This work may provide a new direction for further improving the long amp; 8208;term stability and performance of perovskite solar cell

In situ Near-Ambient Pressure X-ray Photoelectron Spectroscopy Reveals the Influence of Photon Flux and Water on the Stability of Halide Perovskite

For several years, scientists have been trying to understand the mechanisms that reduce the long-term stability of perovskite solar cells. In this work, we examined the effect of water and photon flux on the stability of CH3NH3PbI3 perovskite films and solar cells using in situ near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), field emission scanning electron microscopy (FESEM), and current density–voltage (J–V) characterization. The used amount of water vapor (up to 1 mbar) had a negligible impact on the perovskite film. The higher the photon flux, the more prominent were the changes in the NAP-XPS and FESEM data; also, a faster decline in power conversion efficiency (PCE) and a more substantial hysteresis in the J-V characteristics were observed. Based on our results, it can be concluded that the PCE decrease originates from the creation of Frenkel pair defects in the perovskite film under illumination. The stronger the illumination, the higher the number of Frenkel defects, leading to a faster PCE decline and more substantial hysteresis in the J-V sweeps