Surface Structure and Photocatalytic Properties of Bi₂WO₆ Nanoplatelets Modified by Molybdena Islands from Chemical Vapor Deposition

Abstract

We report on a novel route of preparing molybdena-modified bismuth tungstates and their successful application in the photocatalytic oxygen evolution reaction and the oxidation of glycerol. Hierarchically assembled monocrystalline Bi 2 WO 6 nanoplatelets with a specific surface area of 10 m 2 /g were obtained applying a hydrothermal synthesis method using Na 2 WO 4 and Bi(NO 3 ) 3 as precursors, followed by a solvent-free chemical vapor deposition method using Mo(CO) 6 , resulting in highly dispersed molybdena species. Extensive characterization using X-ray photoelectron spectroscopy, low-energy ion scattering, and Raman spectroscopy showed that microcrystalline MoO 3 islands were formed on the bismuth tungstate surface that grew in height and lateral dimension with increasing loading. Correspondingly, the molybdena-modified materials were found to have favorable photocatalytic and photoelectrochemical properties in the oxygen evolution reaction and the selective oxidation of glycerol.

Recent Advances in Thermo-, Photo-, and Electrocatalytic Glycerol Oxidation

“…265 Muhler and co-workers modified Bi 2 WO 6 nanoplatelets with MoO x , deposited via chemical vapor deposition (CVD), and investigated the photocatalytic activity of these materials for oxygen evolution and selective glycerol oxidation. 271 The authors could show that under UV−vis irradiation the unmodified Bi 2 WO 6 exhibited no photocatalytic activity for glycerol oxidation. This is in contrast to the results reported by Xu et al 263 and might be due to the different preparation methods of the materials.…”

“…Among those, solar water splitting for hydrogen generation, , CO 2 reduction, − and pollutant degradation , have been intensively studied. On the other hand, reports for the selective oxidation of glycerol over semiconductor photocatalysts are scarcely available and have only emerged during the past decade, − although selective transformations of organic compounds via photocatalysis have gained great interest for a vast amount of other substrates. ,− Generally, in heterogeneous photocatalysis, the photon energy of the impinging (solar) light is absorbed by a semiconductor and transformed into charge carriers (positively charged holes and negatively charged electrons). The migration of the charge carries to the photocatalyst surface allows their subsequent transfer to adsorbed species in order to drive the chemical reaction.…”

Strategies for Semiconductor/Electrocatalyst Coupling toward Solar‐Driven Water Splitting

“…Given the ease of CVD growth of Mo‐based catalysts and their decent catalytic performance for HER or OER, Mo‐based catalysts including MoS 2 , MoO 3 , MoS x Cl y , have been explored to couple with semiconductor photoelectrodes for PEC water splitting. Using CVD, Zhang et al deposited MoS 2 NSs on Ag@Si nanosphere array photocathodes, using MoO 3 and sulfur (S) powders as the reaction precursors .…”

Highly Efficient Visible Light Photocatalytic Activities in Self‐Assembled Metastable TiO2/Bi4MoO9 Heterojunctions

“…[29] As shown in Figure 2 reduced Mo 5+ . [30] Similar to the Bi 2+ case, the significant decrease in intensity of the Mo 5+ peaks in of photo-generated electron-hole pairs in the process of photocatalysis. [13,16] In contrast, the the critical concentration of heterogeneous nucleation is lower than that of homogeneous nucleation under a given condition.…”