Niobium pentoxide ultra-thin nanosheets: A photocatalytic degradation and recyclable surface-enhanced Raman scattering substrate

Theoretical and Experimental Studies of Ti3C2 MXene for Surface-Enhanced Raman Spectroscopy-Based Sensing

“… 12 − 15 In contrast, semiconductor-based SERS substrates have many charming advantages of biocompatibility, spectral stability, and selective enhancement of molecules to expand their application field. In recent years, more and more researchers have been engaging in exploiting novel SERS-active semiconductor substrates and exploring the intrinsic enhancement mechanism, such as hydrogenated black and amorphous TiO 2 with excellent SERS sensitivity and signal reproducibility, 16 , 17 Nb 2 O 5 nanoflowers and Ta 2 O 5 nanorods with remarkable SERS effect and photocatalytic degradation, 18 , 19 W 18 O 49 and MoS 2 nanosheets regulating SERS sensitivity by oxygen vacancies or oxygen atoms, 20 − 23 a ZnSe substrate 24 with a great enhancement factor value of 2 × 10 6 , and Cu 2 O concave spheres or polyhedron with ultrasensitive SERS activity. 25 , 26 Their SERS activities are mainly attributed to the photoinduced charge transfer (PICT) of CM.…”

Nb2O5‐Based Photocatalysts

“…[82,85j] Besides, the concentration of oxygen va-cancies can be increased when Nb 2 O 5 catalysts were doped with N, Zr, Y, Zn, or Mo species. [77,90,184] These phenomena were also observed on other metal oxides, like Cu-CeO 2 . [250] As a result, the photocurrent density of N-Nb 2 O 5 was higher than that of the pristine one.…”

“…[89] Other metal atoms, like Mo atoms, can be introduced into the Nb 2 O 5 lattices, which were synthesized from the hydrothermal process of ultrathin Nb 2 O 5 nanosheets and ammonium molybdate. [90]…”

“…[17c,242] The HNb 3 O 8 nanosheets exhibited a wide bandgap (≈3.4 eV), corresponding to the absorption spectrum within 370 nm. [90] With the formation of oxygen vacancies, the bandgap of HNb 3 O nanosheets was narrowed. [50f] Moreover, new energy states with a small bandgap (<0.5 eV) were observed with the increasing concentration of surface unsaturated Nb sites and oxygen vacancies.…”

“…[77] Similarly, the intact interaction between methyl violet molecules and Mo-Nb 2 O 5 cluster was speculated, as revealed by the results of surface-enhanced Raman scattering (SERS) and first-principles calculation. [90] Furthermore, CO was obtained with a selectivity of 99.5% from the hydrogenation of gaseous CO 2 using the small Pd nanocrystals supported on Nb 2 O 5 . [253] Density functional theory (DFT) calculations suggested that the Pd(111) facets dominated on the larger nanoparticles were the most favorable sites for methanation of CO 2 .…”