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Aqueous zinc ion batteries (AZIBs) have considerable potential for energy storage owing to their cost-effectiveness, safety, and environmental sustainability. However, dendrite formation, hydrogen evolution reaction (HER), and corrosion of the bare zinc (B-Zn) anode tremendously impact the performance degradation and premature failure of AZIBs. This study introduces a glancing angle deposition (GLAD) approach during the sputtering process to fabricate tellurium nanostructured (TeNS) at the zinc (Zn) anode to avoid the aforementioned issues with the B-Zn anode. Three different deposition times (5, 10, and 30 min) were used to prepare TeNS at the Zn anode. The morphology, crystallinity, composition, and wettability of the TeNSs were analyzed. The TeNSs served as hydrophilic sites and a protective layer, facilitating uniform Zn nucleation and plating while inhibiting dendrite formation and side reactions. Consequently, the symmetric cell with TeNS deposited on the Zn anode for 10 min (Te@Zn_10 min) demonstrated an enhanced cycling stability of 350 h, the lowest nucleation overpotential of 10.65 mV at a current density of 1 mA/cm2, and an areal capacity of 0.5 mAh/cm2. The observed enhancement in the cycling stability and reduction in the nucleation overpotential can be attributed to the optimal open area fraction of the TeNSs on the Zn surface, which promotes uniform Zn deposition while effectively suppressing side reactions. 

Cobalt-based catalysts are recognized as promising electrocatalysts for oxygen reduction reactions (ORRs) in fuel cells that operate within acidic electrolytes. A synthesis process involving a cobalt complex, nanocellulose, and dopamine, followed by pyrolysis at 500 °C under a nitrogen atmosphere, was used to create a cobalt and nitrogen-doped carbonaceous material. Additionally, urea was incorporated to enhance nitrogen doping in the carbonaceous material. The morphology and structure of the material were examined using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD), where SEM unveiled dispersed metal oxides within the carbonaceous framework. Energy Dispersive X-ray Spectroscopy (EDS) analysis showed an even distribution of elements across the cobalt-doped carbonaceous material. X-ray Photoelectron Spectroscopy (XPS) analysis further highlighted significant alterations in the elemental composition due to pyrolysis. The electrochemical behavior of the cobalt-doped carbonaceous material, with respect to the oxygen reduction reaction (ORR) in an acidic medium, was investigated via cyclic voltammetry (CV), revealing an ORR peak at 0.30 V against a reversible hydrogen reference electrode, accompanied by a notably high current density. The catalyst’s performance was evaluated across different pH levels and with various layers deposited, showing enhanced effectiveness in acidic conditions and a more pronounced reduction peak with uniformly applied electrode layers. Rotating disk electrode (RDE) studies corroborated the mechanism of a four-electron reduction of oxygen to water, emphasizing the catalyst’s efficiency. 

Bismuth oxide is an important bismuth compound having applications in electronics, photo-catalysis and medicine. At the nanoscale, bismuth oxide experiences a variety of new physico-chemical properties because of its increased surface to volume ratio leading to potentially new applications. In this manuscript, we report for the very first time the synthesis of bismuth oxide (Bi 2 O 3 ) nano-flakes by pulsed laser ablation in liquids without any external assistance (no acoustic, electric field, or magnetic field). The synthesis was performed by irradiating, pure bismuth needles immerged in de-ionized water, at very high fluence ∼160 J cm −2 in order to be highly selective and only promote the growth of two-dimensional structures. The x - and y -dimensions of the flakes were around 1 μm in size while their thickness was 47.0 ± 12.7 nm as confirmed by AFM analysis. The flakes were confirmed to be α- and γ-Bi 2 O 3 by SAED and Raman spectroscopy. By using this mixture of flakes, we demonstrated that the nanostructures can be used as antimicrobial agents, achieving a complete inhibition of Gram positive (MSRA) and Gram negative bacteria (MDR-EC) at low concentration, ∼50 ppm.