Development of visible-light-driven photocatalysts by employing a relatively simple, efficient, and cost-effective one-step process is essential for commercial applications. Herein, we report for the first time the synthesis of in situ Cu-ion modified Ti self-doped rutile TiO by such a facile one-step solution precursor plasma spray (SPPS) process using a water-soluble titanium precursor. In the SPPS process, Ti self-doping on Ti of rutile TiO is found to take place because of electron transfer from the created oxygen vacancies to Ti-ions. In situ Cu modification of the above Ti self-doped rutile TiO by additionally introducing a Cu solution into plasma plume is also demonstrated. While the Ti self-doping induces broad absorption in the visible-light region, the addition of Cu ion leads to even broader absorption in the visible region owing to resulting synergistic properties. The above materials were evaluated for various self-cleaning photocatalytic applications under visible-light illumination. Cu-ion modified Ti self-doped rutile TiO is noted to exhibit a remarkably enhanced visible-light activity in comparison with Ti self-doped rutile TiO, with the latter itself outperforming commercial TiO photocatalysts, thereby suggesting the suitability of the material for indoor applications. The broad visible-light absorption by Ti self-doping, the holes with strong oxidation power generated in the valence band, and electrons in Ti isolated states that are effectively separated into the high reductive sites of Cu ions upon visible-light irradiation, accounts for improved photocatalytic activity. Moreover, the synthesis process (SPPS) provides a valuable alternative to orthodox multistep processes for the preparation of such visible-light-driven photocatalysts.

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Discovery of advanced soft-magnetic high entropy alloy (HEA) thin films are highly pursued to obtain unidentified functional materials. The figure of merit in current nanocrystalline HEA thin films relies in integration of a simple single-step electrochemical approach with a complex HEA system containing multiple elements with dissimilar crystal structures and large variation of melting points. A new family of Cobalt–Copper–Iron–Nickel–Zinc (Co–Cu–Fe–Ni–Zn) HEA thin films are prepared through pulse electrodeposition in aqueous medium, hosts nanocrystalline features in the range of ~ 5–20 nm having FCC and BCC dual phases. The fabricated Co–Cu–Fe–Ni–Zn HEA thin films exhibited high saturation magnetization value of ~ 82 emu/g, relatively low coercivity value of 19.5 Oe and remanent magnetization of 1.17%. Irrespective of the alloying of diamagnetic Zn and Cu with ferromagnetic Fe, Co, Ni elements, the HEA thin film has resulted in relatively high saturation magnetization which can provide useful insights for its potential unexplored applications.

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The production of high entropy alloy-based nanocomposites is an exciting yet challenging area in terms of its scalability and industrial applications. Here we developed graphene oxide (GO) reinforced FeCoNiCuZn high entropy alloy (HEA) nanocomposites through an electrochemical approach using aqueous medium in a single step. Transmission electron microscopy observations confirmed uniformly distributed nanocrystalline dual FCC phase quinary alloy nanoparticles throughout the GO layers. On the other hand, the presence of GO affects the electrochemical reduction of multiple elements during alloy formation in the deposition process, which often leads to dual phases with slight deviations in alloy composition, unlike the pure metal-GO composites. Additionally, incorporation of GO has not shown any effect on the ferromagnetic nature of FeCoNiCuZn HEA with saturation magnetization (Ms) ~43.5emu/g. The obtained saturation magnetization is relatively higher compared to the existing reported magnetic nanoparticles with GO. Hence, this technique shows its potential applicability and provides an old technique yet a new approach for synthesizing GO-HEA nanocomposites for various magnetic applications.