Biomimetic Catalysts Based on Au@TiO2-MoS2-CeO2 Composites for the Production of Hydrogen by Water Splitting

Abstract

The photocatalytic hydrogen evolution reaction (HER) by water splitting has been studied, using catalysts based on crystalline TiO2 nanowires (TiO2NWs), which were synthesized by a hydrothermal procedure. This nanomaterial was subsequently modified by incorporating different loadings (1%, 3% and 5%) of gold nanoparticles (AuNPs) on the surface, previously exfoliated MoS2 nanosheets, and CeO2 nanoparticles (CeO2NPs). These nanomaterials, as well as the different synthesized catalysts, were characterized by electron microscopy (HR-SEM and HR-TEM), XPS, XRD, Raman, Reflectance and BET surface area. HER studies were performed in aqueous solution, under irradiation at different wavelengths (UV-visible), which were selected through the appropriate use of optical filters. The results obtained show that there is a synergistic effect between the different nanomaterials of the catalysts. The specific area of the catalyst, and especially the increased loading of MoS2 and CeO2NPs in the catalyst substantially improved the H2 production, with values of ca. 1114 μm/hg for the catalyst that had the best efficiency. Recyclability studies showed only a decrease in activity of approx. 7% after 15 cycles of use, possibly due to partial leaching of gold nanoparticles during catalyst use cycles. The results obtained in this research are certainly relevant and open many possibilities regarding the potential use and scaling of these heterostructures in the photocatalytic production of H2 from water.

Sensitive and Reversible Ammonia Gas Sensor Based on Single-Walled Carbon Nanotubes

“…The exfoliation process reveals the fine details of the atomic monolayer, as evident in the image. As previously reported in publications by our research group [35], MoS2 exhibits a high degree of crystallinity, which is corroborated by the inset of Figure 4c. Additionally, the material also contains structural defects, which may potentially influence its properties and behavior.…”

MXene‐CeO2@PDA Synergistically Enhanced Anticorrosion of Waterborne Epoxy Coating

“…The CeO 2 shows a sharp and typical characteristic peak at about 457 cm −1 . [ 30 ] The PDA exhibits two characteristic peaks at about 1354 and 1573 cm −1 , which are respectively assigned to the stretching vibration and deformation of catechol groups. [ 31 ] The MXene displays a characteristic peak at 202 cm −1 and two obvious characteristic peaks at 1352 and 1580 cm −1 , which are well‐known for the D band and G band, respectively.…”

Synergistic Effects of Co3O4-gC3N4-Coated ZnO Nanoparticles: A Novel Approach for Enhanced Photocatalytic Degradation of Ciprofloxacin and Hydrogen Evolution via Water Splitting

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