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Through hybrid functional calculations, we study the elastic, electronic and optical properties of the two-dimensional (2D) PtX 2 (X = S, Se and Te) monolayer. The lattice constants increases and the band gap values decrease monotonously with increasing atomic number of chalcogenide elements. The tensile strain can reduce the band gaps and affect optical properties of 2D PtX 2 monolayers. Also, the indirect band structures are kept under considered strain range. Our results show that about −3% of compressive strain can induce semiconductor-to-metal transition. Moreover, the in-plane stiffness are 81 N/m for PtS 2 , 64 N/m for PtSe 2, and 40 N/m for PtTe 2, which are smaller than that of 2D MoX 2 monolayers. [ABSTRACT FROM AUTHOR]

[Display omitted] • The AlOOH@Ag as SERS substrate successfully applied to detect Congo Red. • The AlOOH@Ag has excellent adsorption properties to remove harmful molecules. • Dual-functional SERS sensor successfully achieved the detection in real samples. As an excellent nanomaterial, AlOOH has a molecular enrichment effect derived from the large number of hydroxyl groups on its surface and its porous structure, which increases the molecular density in the hot spot region of Ag nanoparticles with plasmonic properties, provides the surface-enhanced Raman scattering (SERS) activity and realizes the detection of probe molecules. In our work, the composite AlOOH@Ag is rationally formed as an SERS substrate successfully applied to the detection of Congo Red (CR) molecules even at the trace level thanks to the formation of hydrogen bonds. Our successful analysis of the toxic dye molecules Rhodamine 6G (R6G), Crystal Violet (CV) and CR in a mixture demonstrates the universality of AlOOH@Ag as an SERS substrate and the great potential for recognition of a target. Importantly, the AlOOH@Ag has excellent molecular adsorption properties to remove harmful molecules, and a dual-functional SERS sensor that integrates detection and removal is achieved. Monitoring and adsorption tests under different pH spectrum environments were also performed. Importantly, the detection in real samples is even more successful. This versatile all-in-one SERS substrate provides platforms for the development of convenient sensors to be applied in actual environmental processing. [ABSTRACT FROM AUTHOR]