Indoor water splitting for hydrogen production through electrocatalysis using composite metal oxide catalysts

This study explores an optimistic approach for large-scale hydrogen production by employing electrocatalysts based on nickel, cobalt, iron, and aluminum oxides as alternatives to costlier metals. This approach offers a cost-effective solution to electrolysis in water media for hydrogen production. This investigation is focused on the electrolysis process, engaging NiO–Al2O3–CoO–Fe2O3 in 1M solution of NaOH and KOH. The environmental and economic analyses are conducted to evaluate the overall effect and cost-effectiveness of the electrolysis process. These findings provide valuable insights into the performance, feasibility, and challenges of using oxides of aluminum, nickel, iron, and cobalt in electrolysis for hydrogen production. The structural and morphological analyses of metal oxides are conducted using XRD and SEM tools, which showed reduced crystallinity and open pore structure of the samples. Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), and Linear Sweep Voltammetry (LSV) revealed a higher electrocatalytic activity, a larger electrochemical active surface area, a higher current density, and a high density of active sites of NiO–Al2O3–CoO–Fe2O3 composite. Electrode 1 of the composite catalyst produced 500 ml of hydrogen after 30 min of the process, while electrodes 2 and 3 produced 263 and 249 ml of hydrogen, respectively. This study also elucidated the electrocatalytic mechanism involved in water splitting using these composite materials

Photocatalytic response of plasma functionalized and sonochemically TiO2/BiOBr coated fabrics for self-cleaning application

Sonochemical synthesis of nanophotocatalysts to produce functionalized fabrics is gaining significant attention worldwide. This study deals with coating sonochemically synthesized TiO2 and TiO2/BiOBr photocatalysts on pre-coating plasma functionalized cotton fabric. The photocatalytic activity of pristine, plasma-functionalized, and photocatalyst-coated fabrics was checked by degrading methyl red, Rhodamine B, and methyl orange under sunlight irradiation. The surface morphology, optical properties, structure, and purity of the coating material were elaborated using UV-visible spectroscopy, electrical resistivity measurements, x-ray diffraction measurements, inductively coupled plasma atomic emission spectroscopy analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy. The nanoparticle-coated fabrics significantly reduced the photoluminescence intensity compared to plasma-functionalized fabrics. The TiO2/BiOBr decorated fabric had significantly higher photocatalytic efficiency than all other fabric samples. This photocatalyst showed 84% efficiency against Rhodamine B, 58% against methyl orange, and 55% against methyl red. The-self-cleaning UV protection applications of these photocatalyst-decorated fabrics are suggested in this study

Study of dual Z-scheme photocatalytic response of TiO2/Ag/ZnO coating on plasma-modified cotton fabric for self-cleaning application

An innovative approach was adopted to improve the photocatalytic response of nanoparticle-coated cotton fabric for self-cleaning application. Fabrics with layers of TiO2, Ag, and ZnO nanoparticles were assessed for photodegradation of Rhodamine B, methyl orange, and methyl red. A dual-scheme charge transfer method was designed for the photocatalytic activity of TiO2/Ag/ZnO nanoparticles on cotton fabric. To produce the multilayer structure of nanoparticles, the fabric was first functionalized with atmospheric pressure nonthermal plasma and then sonochemically coated with TiO2/Ag/ZnO in a layered form. The plasma functionalization enhanced the stability of TiO2/Ag/ZnO nanoparticles on the fabric. It was revealed that a combination of Ag, TiO2, and ZnO nanoparticles produced a Schottky barrier among the silver metal and metal oxides (TiO2 and ZnO), resulting in enhanced photocatalytic properties. Methyl red underwent the highest photocatalytic degradation of 93% over the designed photocatalyst-coated fabric after 120 min of light exposure. This study provides a promising strategy for improving the photocatalytic self-cleaning efficacy of nanocoated fabrics

Production and characterization of CuNiZnFe2O4 dispersed transformer and kerosene oil based magnetic nanofluids for heat transfer applications

This study produced nanofluids via a two-step method by dispersing copper–nickel–zinc (CuNiZnFe2O4) ferrite nanocomposites in transformer and kerosene oils. A sol–gel auto-combustion approach was adopted to synthesize ferrite nanoparticles. The prepared nanoparticles were analyzed through scanning electron microscopy, photoluminescence spectroscopy, and x-ray diffraction. The measured crystallite size varied between 11 and 13 nm. The SEM images show that the structures of the developed CuNiZn nanoparticles are irregular. The photoluminescence results give a bandgap of 1.91 eV and the emission lines of the nanoparticles. Transient hot wire analysis was performed to determine the thermal conductivity of the base fluid and the prepared nanofluids. It is observed that nanoparticles in the nanofluid enhance the heat transfer rate. It has been proven that CuNiZn/kerosene-based nanofluids have greater thermal conductivity than CuNiZn/transformer oil-based nanofluids. The viscosity of transformer oil-based nanofluids at room temperature is 12.53 mm2 s−1, which decreases to 12.49 mm2 s−1 at 40 °C. Similarly, the viscosity of kerosene-based nanofluids is 1.49 mm2 s−1 at room temperature and 1.16 mm2 s−1 at 40 °C. The sedimentation method revealed that CuNiZn/transformer oil-based nanofluids have greater stability than CuNiZn/kerosene-based nanofluids