Synergetic contribution of enriched selenium vacancies and out-of-plane ferroelectric polarization in AB-stacked MoSe₂ nanosheets as efficient piezocatalysts for TC degradation

Abstract

In this research, ultrathin MoSe2 nanosheets (MoSe2 NSs) with enriched selenium vacancy (Se-vacancy) were prepared by a HNO3-assisted exfoliation strategy. The features of synthesized catalysts were characterized by SEM, TEM,...

Large-scale fabrication and Mo vacancy-induced robust room-temperature ferromagnetism of MoSe2 thin films

“…Fig. 4d shows that all the samples exhibit a sharply paramagnetic absorption signal around 3516 G (g = 2.00) due to the charge state of V Se s 10 and a lower and broader signal around 3624 G (g = 1.95) that arises from V Mo s. 22 The EPR results indicate that V Mo s and V Se s both exist in the MoSe 2 thin films, consistent with the STEM results. The EPR signal around 3516 G is higher than that around 3624 G, indicating that the V Se concentration is higher than the V Mo concentration, which is because the formation energy of V Se is lower than that of V Mo even under Se-rich conditions.…”

“…2c all display two peaks located at 54.88 eV and 55.78 eV, corresponding to Se 2− 3d 5/2 and 3d 3/2 of 2H-MoSe 2 , respectively. 22,23 The detailed compositional analysis of the XPS data indicates that the atomic ratios of Se/Mo in Z1, Z2, Z3 and Z4 are 2.07, 2.05, 2.03 and 2.02, respectively, indicating that all the samples are Se-rich and the Se/Mo ratio decreases with the increase in growth temperature.…”

Scalable Fabrication of High-Performance Self-Powered a-MoSe2 Thin-Film-Based Photodetectors on a-SiO2/Si Substrates

“…The binding energy peaks at 229.18 and 232.38 eV are attributed to Mo 4+ 3d5/2 and Mo 4+ 3d3/2, respectively. The minor peaks located at 230.58 eV are attributed to Se 3s . The peaks located at 54.88 and 55.78 eV correspond to Se 2– 3d5/2 and 3d3/2, respectively.…”

“…3,19 The stoichio-metric ratios (1:2.07 and 1:2.05) are estimated using the spectral areas of Mo 3d and Se 3d, indicating that the a-MoSe 2 thin films is Se-rich. The EPR results in Figure 2d show that M1 and M3 both exhibit a sharply paramagnetic signal around 3516 G (g = 2.003) arising from V Se s 25 and a shorter and broader signal around 3624 G (g = 1.954) due to the charge state of V Mo s, 26 indicating the presence of both V Se s and V Mo s in the a-MoSe 2 thin film even in the Se-rich condition, which is similar to MoS 2 prepared by CVD. 27 Additionally, the signals of M1 are stronger than those of M3 due to its larger thickness.…”

“…The minor peaks located at 230.58 eV are attributed to Se 3s. 25 The peaks located at 54.88 and 55.78 eV correspond to Se 2− 3d5/2 and 3d3/2, respectively. All of the peak positions are consistent with those of 2H-phase MoSe 2 .…”