A DFT investigation on structural, electronic, magnetic, optical, elastic and hydrogen storage properties of Ru-based hydride-perovskites XRuH3 (X = Cr, V, Ni).

The present investigation delves into various physical properties exhibited by CrRuH3, VRuH3 and NiRuH3. Notably adopting a stable cubic configuration, both compounds manifest a distinct metallic demeanor characterized by an absolute absence of band gap. In-depth analysis through Total Density of States (TDOS) and Partial Density of States (PDOS) justify this metallic conduct by distinctly showcasing peak conductivity at the Fermi level. The materials' magnetic behavior reveals an antiferromagnetic disposition for CrRuH3 and NiRuH3, while their intrinsic attributes emerge as anisotropic and rigid. Applying Poisson's ratio (ν) and the B/G ratio, all investigated compounds show ductility, but the CrRuH3 is superior among them. The heightened values of Young's modulus, Bulk modulus, and mean shear modulus observed in CrRuH3 underscore its enhanced rigidity as compared to VRuH3 and NiRuH3. Within the optical realm, CrRuH3 displays notable optical conductivity and absorption, particularly within the lower energy spectrum. Remarkably, at 0 eV, CrRuH3 showcases elevated reflectivity and refractive index as compared to the other investigated materials. On the hydrogen storage front, XRuH3 (X = Cr, V, Ni) exhibit promising potential, yet CrRuH3 emerges as the more favorable candidate for hydrogen storage applications.

Synthesis of Ni9S8/MoS2 heterocatalyst for Enhanced Hydrogen Evolution Reaction.

We demonstrate a heterostructure Ni9S8/MoS2 hybrid with tight interface synthesized via an improved hydrothermal method. As compared to pure MoS2, the increased surface area and the shorten charge transport pathway in the layered hybrid significantly promote the photocatalytic efficiency for hydrogen evolution reaction (HER). In particularly, the optimized Ni9S8/MoS2 hybrid with 20 wt % Ni9S8 exhibits the highest photocatalytic activity with HER value of 406 µmolg-1h-1, which is enhanced by 70% compared to that of pure MoS2 nanosheets (285.0 µmolg-1h-1). Moreover, the value is 4 times more than the commercial MoS2 (92.0 µmolg-1h-1), indicating the high potential of the hybrid in the catalytic fields.