A facile solvothermal method is used to prepare octahedral MOF-801 with a lattice spacing of 0.304 nm representative of ZrO ₂ (011) planes for water defluorination.

Ag-decorated MoS ₂ nanocomposite photocatalyst with enhanced visible-light driven hydrogen gas evolution performance.

We have investigated the electronic structure of ${\mathrm{Sr}}_2{\mathrm{FeMoO}}_6$ by photoemission spectroscopy and band-structure calculations within the local-density $\mathrm{approximation}+U$ $(\mathrm{LDA}+U)$ scheme. In valence-band photoemission spectra, a distinct double-peak feature has been observed near the Fermi level ${(E}_F).\mathrm{}$ A photon-energy dependence of the spectra and the $\mathrm{LDA}+U$ band-structure calculation have revealed that the first peak crossing $E_F$ consists of the (Fe+Mo) $t_{2g\downarrow }$ states and the second peak well below $E_F$ is dominated by the Fe $e_{g\uparrow }$ states. This clearly shows that only the down-spin states contribute to the $E_F$ intensity, thus the half-metallic density of states (DOS) is realized. We point out that the observed half-metallic DOS can be attributed to the strong Hund’s rule energy stabilization due to the high-spin ${3d}^5$ configuration at the Fe site.

In this study, X-ray photoelectron spectroscopy (XPS) was used to study chitosan–graphene oxide (chitosan–GO) incorporated with 4-(2-pyridylazo)resorcinol (PAR) and cadmium sulfide quantum dot (CdS QD) composite thin films for the potential optical sensing of cobalt ions (Co²⁺). From the XPS results, it was confirmed that carbon, oxygen, and nitrogen elements existed on the PAR–chitosan–GO thin film, while for CdS QD–chitosan–GO, the existence of carbon, oxygen, cadmium, nitrogen, and sulfur were confirmed. Further deconvolution of each element using the Gaussian–Lorentzian curve fitting program revealed the sub-peak component of each element and hence the corresponding functional group was identified. Next, investigation using surface plasmon resonance (SPR) optical sensor proved that both chitosan–GO-based thin films were able to detect Co²⁺ as low as 0.01 ppm for both composite thin films, while the PAR had the higher binding affinity. The interaction of the Co²⁺ with the thin films was characterized again using XPS to confirm the functional group involved during the reaction. The XPS results proved that primary amino in the PAR–chitosan–GO thin film contributed more important role for the reaction with Co²⁺, as in agreement with the SPR results.