Construction and performance of CdS/MoO2@Mo2C-MXene photocatalyst for H2 production

Abstract

Nowadays, photocatalytic technologies are regarded as promising strategies to solve energy problems, and various photocatalysts have been synthesized and explored. In this paper, a novel CdS/MoO2@Mo2C-MXene photocatalyst for H2 production was constructed by a two-step hydrothermal method, where MoO2@Mo2C-MXene acted as a binary co-catalyst. In the first hydrothermal step, MoO2 crystals with an egged shape grew on the surface of two-dimensional (2D) Mo2C MXene via an oxidation process in HCl aqueous solution. In the second hydrothermal step, CdS nanorods were uniformly assembled on the surface of MoO2@Mo2C-MXene in ethylenediamine with an inorganic cadmium source and organic sulfur source. The CdS/MoO2@Mo2C-MXene composite with MoO2@Mo2C-MXene of 5 wt% exhibits an ultrahigh visible-light photocatalytic H2 production activity of 22,672 µmol/(g·h), which is ∼21% higher than that of CdS/Mo2C-MXene. In the CdS/MoO2@Mo2C-MXene composite, the MoO2 with metallic nature separates CdS and Mo2C MXene, which acts as an electron-transport bridge between CdS and Mo2C MXene to accelerate the photoinduced electron transferring. Moreover, the energy band structure of CdS was changed by MoO2@Mo2C-MXene to suppress the recombination of photogenerated carriers. This novel compound delivers upgraded photocatalytic H2 evolution performance and a new pathway of preparing the low-cost photocatalyst to solve energy problems in the future.

Deintercalation of Al from MoAlB by molten salt etching to achieve a Mo 2AlB 2 compound and 2D MoB nanosheets

“…Guo and coworkers reported that MoB MBene exhibits great catalytic activity for hydrogen evolution reactions, indicating its promising application as electrocatalysts for hydrogen evolution [28]. In addition, the MoB MBene has a potential application in H2 production, similar to the Mo2C MXene which acts as a visible-light photocatalyst for H2 production partially due to the more activity of Mo element [29,30]. Mo2AlB2 is a MAB phase and has an orthorhombic crystal structure containing stacked M-B blocks interleaved with a monolayer of Al.…”

Self-Supported MoO2/MoSi2 Ceramic Electrode for High Current Density Hydrogen Evolution Reaction

“…The spectrum of Mo 3d was deconvoluted into six peaks (Figure b), corresponding to the Mo 4+ 3d 5/2 and 3d 3/2 , Mo 5+ 3d 5/2 and 3d 3/2 , and Mo 6+ 3d 5/2 and 3d 3/2 (229.9 and 232.5, 231.3 and 234.7, and 233.2 and 236 eV, respectively). ,− The Mo 4+ is originated from MoO 2 . The appearance of Mo 5+ and Mo 6+ is attributed to inevitable oxidation that occurred at the surface of MoO 2 , but the main component is still MoO 2 . , …”

“…The appearance of Mo 5+ and Mo 6+ is attributed to inevitable oxidation that occurred at the surface of MoO 2 , but the main component is still MoO 2 . 37,38 The deconvolution of the O 1s spectrum (Figure 3c) revealed the bonds of O−Mo (530.6 eV) in MoO 2 , and O−H and O−Si (531.4 and 532.3 eV, respectively) from SiO 2 in MoSi 2 . 20,39 The Mo 3d and O 1s XPS spectra of the other MoSi 2 -based electrodes are illustrated in Figure S5, Supporting Information.…”

Mo2C MXene Nanosheets Made in Different Etching Solutions as Co-catalysts for Hydrogen Production

“…This indicates the successful transformation from Mo 2 Ga 2 C to Mo 2 C MXene. 19,20,24,32,33 All the Mo The XPS spectra of pure CdS, CM-Li, and Mo 2 C−Li are shown in Figure 2. From the full-scale XPS spectrum in Figure 2a, the elements of Cd, S, O, and Mo were detected in the typical CM-Li.…”