Carbon-supported transition-metal materials have been recognized as efficient bifunctional electrocatalysts for oxygen evolution/reduction reactions (OER/ORR) in rechargeable zinc-air batteries. While the pursuit of high-performance catalysts remains critical, the industrial applications of catalysts and their synthesis methods cannot be ignored. In this work, a self-supported hybrid catalyst is prepared by anchoring cobalt oxide particles on defective carbon papers. Commercial carbon papers were first treated by nitrogen plasma to introduce surface defects and increase their surface hydrophilicity, thereby facilitating the subsequent cobalt deposition. The resulting catalyst with abundant carbon defects and deposited Co oxide particles exhibits an increased number of active sites and improved surface conductivity compared to pristine carbon papers, leading to enhanced bifunctional electrocatalytic performance. When employed in a liquid zinc-air battery, this catalyst shows acceptable discharging and charging potentials, along with a higher durability than the battery utilizing a mixed noble metal-based catalyst. Our findings represent a novel and large-scale application strategy for synthesizing self-supported carbon-supported transition-metal materials for rechargeable zinc-air batteries and associated energy storage systems.

ZIF-8 provides accessible channel to small molecules like hydrogen to pass through the pores to interact at the CuO:Al surface. The interaction strength of VOCs with ZIF-8 is defined by the electronic polarizability of tested VOCs.

In recent years, defective TiO₂ has caught considerable research attention because of its potential to overcome the limits of low visible light absorption and fast charge recombination present in pristine TiO₂ photocatalysts. Among the different synthesis conditions for defective TiO₂, ambient pressure hydrogenation with the addition of Ar as inert gas for safety purposes has been established as an easy method to realize the process. Whether the Ar gas might still influence the resulting photocatalytic properties and defective surface layer remains an open question. Here, we reveal that the gas flow ratio between H₂ and Ar has a crucial impact on the defective structure as well as the photocatalyic activity of TiO₂. In particular, transmission electron microscopy (TEM) in combination with electron energy loss spectroscopy (EELS) revealed a larger width of the defective surface layer when using a H₂/Ar (50 %–50 %) gas mixture over pure H₂. A possible reason could be the increase in dynamic viscosity of the gas mixture when Ar is added. Additionally, photoinduced enhanced Raman spectroscopy (PIERS) is implemented as a complementary approach to investigate the dynamics of the defective structures under ambient conditions which cannot be effortlessly realized by vacuum techniques like TEM.

Background cold atmospheric plasma (CAP) is known to be a surface-friendly yet antimicrobial and activating process for surfaces such as titanium. The aim of the present study was to describe the decontaminating effects of CAP on contaminated collagen membranes and their influence on the properties of this biomaterial in vitro. Material and Methods: A total of n = 18 Bio-Gide^® (Geistlich Biomaterials, Baden-Baden, Germany) membranes were examined. The intervention group was divided as follows: n = 6 membranes were treated for one minute, and n = 6 membranes were treated for five minutes with CAP using kINPen^® MED (neoplas tools GmbH, Greifswald, Germany) with an output of 5 W, respectively. A non-CAP-treated group (n = 6) served as the control. The topographic alterations were evaluated via X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Afterward, the samples were contaminated with E. faecalis for 6 days, and colony-forming unit (CFU) counts and additional SEM analyses were performed. The CFUs increased with CAP treatment time in our analyses, but SEM showed that the surface of the membranes was essentially free from bacteria. However, the deeper layers showed remaining microbial conglomerates. Furthermore, we showed, via XPS analysis, that increasing the CAP time significantly enhances the carbon (carbonyl group) concentration, which also correlates negatively with the decontaminating effects of CAP. Conclusions: Reactive carbonyl groups offer a potential mechanism for inhibiting the growth of E. faecalis on collagen membranes after cold atmospheric plasma treatment.

A setup consisting of two atmospheric plasma sources is used for the combined synthesis and passivation of nanoparticles. The silicon nanoparticles synthesized in the first source are analyzed for their chemical composition, morphology, and photoluminescence. The particles are then treated with a second plasma to induce surface passivation. The passivation process of the particles is monitored in real time using in situ infrared absorption spectroscopy. The results indicate that this treatment induces methylation of the silicon nanocrystals, which is further supported by XPS analysis. This surface passivation shifts the maximum of the photoluminescent signal to blue in the visible spectral region. Further optimization of the reported nanoparticle passivation process can provide a flexible tool for tuning nanoparticle properties.