Here, we present for the first time an Au–CeO₂ nanocomposite synthesized in the presence of a mild pressure of oxygen (1.33 Pa) by the cross-beam laser deposition technique. The deposit was grown on a conductive (current collector) substrate composed of a porous network of carbon microfibers. The structure and morphology of the deposit were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). XPS analysis demonstrated that the interaction of Au with CeO₂ during deposition induced charge redistribution in the ceria nanoparticles (Ce^3+,4+), resulting in positively charged Au species (Au³⁺). TEM analysis revealed that the basal planes of the carbon fibers are coated with a monolayer of interconnected nanoparticles, whereas their outer walls are covered with an ultra-thin film (∼40 nm thickness) formed of nanoparticles gathering into columns. The direct electrocatalytic oxidation of glucose in a neutral medium, such as phosphate buffered saline (pH = 7.2) solution, has been investigated with cyclic voltammetry, chronoamperometry and square-wave voltammetry. Sensitivity as high as 57.5 μA cm⁻² mM⁻¹ up to 10 mM of glucose and a low detection limit of 10 μM were obtained with square-wave voltammetry. Such electrocatalytic activity is because of the presence of cationic gold (electronic effect) and the size reduction of gold particles (size effect). This interesting analytical performance in addition to the low loading of gold (100 μg cm⁻²) makes the laser fabricated Au–CeO₂ nanocomposite electrode potentially promising for glucose fuel cells, assessment of glucose in biological fluids, as well as in the analysis of food and beverages.

We report the synthesis of an advanced carbon paper (CP) macro-substrate (current collector)/carbon nanotubes (catalyst support)/Pt₇₅Sn₂₅ (nanocatalyst) architecture. The Pt₇₅Sn₂₅ was synthesized onto carbon nanotubes by mean of the cross-beam laser deposition (CBLD) technique. By varying the background gas pressure in the deposition chamber, smooth to porous structures Pt₇₅Sn₂₅ perfectly coating the carbon nanotubes were obtained. Pt₇₅Sn₂₅ deposited under 2 Torr of He resulted in a unique cauliflower-like nanostructure. This nanostructure when used as an electrode exhibits an enhanced electrocatalytic activity and high stability towards ethanol oxidation, a reaction of technological importance to direct ethanol fuel cells.

Efficient and sustainable energy storage remains a critical challenge in the advancement of energy technologies. This study presents the fabrication and electrochemical evaluation of a self-supporting electrode material composed of MnO₂ nanorods grown directly on a carbon paper and carbon nanotube (CNT) substrate using a hydrothermal method. The resulting CNT/MnO₂ electrodes exhibit a unique structural architecture with a high surface area and a three-dimensional hierarchical arrangement, contributing to a substantial electrochemical surface area. Electrochemical testing reveals remarkable performance characteristics, including a specific capacitance of up to 316.5 F/g, which is 11 times greater than that of conventional CP/MnO₂ electrodes. Moreover, the CNT/MnO₂ electrodes demonstrate outstanding retention capacity, exhibiting a remarkable 165% increase over 10,000 cycles. Symmetric supercapacitor devices utilizing CNT/MnO₂ electrodes maintain a large voltage window of 3 V and a specific capacitance as high as 200 F/g. These results underscore the potential of free-standing CNT/MnO₂ electrodes to advance the development of high-performance supercapacitors, which can be crucial for efficient and sustainable energy storage solutions in various industrial and manufacturing applications.