In this study, the electrocatalytic properties of single-phase face-centered cubic high entropy alloy electrodes with equiatomic compositions of CoNiFeCr, CoNiFeV, and CoNiFe(Cr/V) are explored for the hydrogen evolution reaction (HER) in 1M KOH and 0.5M H2SO4. Among these, the CoNiFe(Cr/V) High Entropy Alloy (HEA) electrodes exhibited superior performance, achieving overpotentials of 277 and 45 mV (vs reference hydrogen electrode) at 10 mA/cm2 in alkaline and acidic media, respectively, surpassing their counterparts and approaching the efficiency of commercial Raney-Ni and Pt/C catalysts. Long-term stability tests, including steady state chronoamperometry and potentiodynamic cyclic voltammetry, revealed remarkable corrosion resistance in both environments. The catalytic activity was significantly enhanced by the inclusion of Cr and V. These oxyphilic elements, with their larger atomic radii, induce a heterogeneous surface charge distribution that enhances the electrocatalytic performance of the CoNiFe(Cr/V) HEA. This work highlights a promising candidate for HER applications and sets the stage for a broader exploration of high entropy alloys in advanced catalytic systems.

Biohydrogen is a source of renewable and clean energy. Many countries are working to generate biohydrogen energy as a means of combating the present global warming trend. This review paper aims to highlight the available information on hydrogen production from municipal solid waste biomass and...

Polychlorinated dibenzofurans (PCDFs) are persistent toxic compounds that are ubiquitous in the environment. Nanocomposites of titanium(IV) oxide-vanadium(III) oxide (${\mathrm{Ti}}_3{\mathrm{V}}_2{\mathrm{O}}_7$) and titanium(IV) oxide-silicon dioxide (${\mathrm{Ti}}_2{\mathrm{Si}}_7{\mathrm{O}}_{30}$) were prepared and spectroscopically analyzed as potential decontaminants for dioxin-like materials. The analysis confirmed a homogeneous morphology with nanoscale particle size. The Ti-Si sample was found to have a high surface area compared to the Ti-V composite. Vanadium(III) oxide (V₂O₅) and silicon dioxide (SiO₂) were chosen as materials for the formation of heterogeneous compounds with titanium(IV) oxide (TiO₂) because they possess a suitable band alignment with TiO_2, thus forming effective photocatalysts. This study evaluated the photodegradation of 2,3,7,8-tetrachlorodibenzo-furan (TCDF) in the presence of Ti-Si and Ti-V oxide composites, which was tested using high- (254 nm) and midenergy (302 nm) UV irradiation sources. While Ti-Si showed success in the photodegradation of 2,3,7,8-TCDF dissolved in a (1:1) methanol–tetrahydrofuran (MeOH-THF) solution, the Ti-V composite proved to be a powerful material in adsorbing TCDF with a high capacity immediately upon mixing. Ti-Si oxide was found to decompose TCDF under the two irradiation sources with 98–99% degradation occurring after 70 min. The use of 254 nm as an irradiation source in the presence of Ti-Si was 4.3 times faster than the analogue reaction irradiated without a catalyst. Byproducts of the degradation were evaluated using gas chromatography–mass spectrometry (GC–MS), resulting in a lower chlorinated congener and less toxicity, as the main degradation product.