Vertically aligned bundles of Nb(2)O(5) nanocrystals were fabricated by pulsed laser deposition (PLD) and tested as a photoanode material in dye-sensitized solar cells (DSSC). They were characterized using scanning and transmission electron microscopies, optical absorption spectroscopy (UV-vis), and incident-photon-to-current efficiency (IPCE) experiments. The background gas composition and the thickness of the films were varied to determine the influence of those parameters in the photoanode behavior. An optimal background pressure of oxygen during deposition was found to produce a photoanode structure that both achieves high dye loading and enhanced photoelectrochemical performance. For optimal structures, IPCE values up to 40% and APCE values around 90% were obtained with the N(3) dye and I(3)(-)/I(-) couple in acetonitrile with open circuit voltage of 0.71 V and 2.41% power conversion efficiency.

Although the use of reactive oxygen species (ROS) has been extensively studied, current systems employ external stimuli such as light or electrical energy to produce ROS, which limits their practical usage. In this report, biocompatible metals were used to construct a novel electrochemical system that can spontaneously generate H2O2 without any external light or voltage. The corrosion of Mg transfers electrons to Au-decorated oxidized Ti in an energetically favorable process, and the spontaneous generation of H2O2 in an oxygen reduction reaction was revealed to occur at titanium by combined spectroscopic and electrochemical analyses. The controlled release of H2O2 noticeably enhanced in vitro angiogenesis even in the absence of growth factors. Finally, a new titanium implant prototype was developed by Mg incorporation, and its potential for promoting angiogenesis was demonstrated.

Incorporating UV-sensitive electron transport layers (ETLs) into organic bulk heterojunction (BHJ) photovoltaic devices dramatically impacts short-circuit current (Jsc) and fill factor characteristics. Resistivity changes induced by UV illumination in the ETL of inverted BHJ devices suppress bimolecular recombination producing up to a two orders of magnitude change in Jsc. Electro-optical modeling and light intensity experiments effectively demonstrate that bimolecular recombination, in the form of diode current losses, controls the extracted photocurrent and is directly dependent on the ETL resistivity.

A new antibacterial strategy for Ti has been developed without the use of any external antibacterial agents and surface treatments. By combining Mg alloys with Ti, H 2 o 2 , which is an oxidizing agent that kills bacteria, was spontaneously generated near the surface of Ti. Importantly, the H 2 o 2 formation kinetics can be precisely controlled by tailoring the degradation rates of Mg alloys connected to Ti. Through microstructural and electrochemical modification of Mg with alloying elements (Ca, Zn), the degradation rates of Mg alloys were controlled, and the H 2 o 2 release kinetics was accelerated when the degradation rate of Mg alloys increased. With the introduction of an in vivo assessment platform comprised of Escherichia coli (E. coli) and transgenic zebrafish embryos, we are able to design optimized antibacterial systems (Ti-Mg and Ti-Mg-3wt% Zn) that can selectively eradicate E. coli while not harming the survival rate, development, and biological functions of zebrafish embryos. We envision that our antibacterial strategy based on utilization of sacrificial Mg alloys could broaden the current palette of antibacterial platforms for metals. the solution gradually increased over time, reaching 33 μM after 2 h of reaction. In the case of the Ti-Mg-3wt%Ca system, the H 2 O 2 -releasing kinetics were significantly accelerated and a solution of approximately 60 μM H 2 O 2 was formed at the same reaction time. In contrast, adopting the Mg-3wt% Zn alloy in the system reduced the formation rate of H 2 O 2 , and only 23 μM H 2 O 2 was generated after 2 h of reaction. It should be noted that the H 2 O 2 release rate increased in the series of Ti-Mg-3wt% Zn < Ti-Mg < Ti-Mg-3wt%Ca and that this trend was identical to that of the degradation rate of Mg alloys ( Figs. 3f and 4a).Along with the fluorometric H 2 O 2 assay results, cyclic voltammetry (CV) analyses further proved the difference in H 2 O 2 -releasing behavior depending on the type of Mg alloy connected to Ti. The oxygen reduction reaction (ORR) current, which is related to the amount of H 2 O 2 generated near Ti 36,37 , increased in the series of Ti-Mg-3wt% Zn < Ti-Mg < Ti-Mg-3wt%Ca, which led to the same conclusion (Fig. 4b). Specifically, for the Ti-Mg-3wt%Ca system, the ORR current at the applied voltage of −0.2 vs. Ag/AgCl was −1.3 mA/cm 2 , which was approximately 4.3 and 1.5 times higher than that of the Ti-Mg-3wt% Zn and Ti-Mg systems, respectively. The controllable H 2 O 2 -releasing kinetics of the Ti-Mg alloy system through degradation engineering of Mg alloys indicated its high feasibility with regard to selective bacterial remediation. Scientific RepoRtS |(2020) 10:6536 | https://doi.www.nature.com/scientificreports www.nature.com/scientificreports/ zebrafish embryos. ZEISS Stemi 2000, LEICA MZFLIII, ZEISS Imager Z1 and ZEISS axioskop, LEICA S6D, LEICA DMI6000B were used to examine zebrafish embryos at approximately 72 and 96 hpf. The assay was replicated three times. Examination of zebrafish heart functionality.For the control group, the heart...

The utilization of cell-manipulating techniques reveals information about biological behaviors suited to address a wide range of questions in the field of life science. Here, we introduced an on/off switchable...