Synergetic Photocatalytic Pure Water Splitting and Self-Supplied Oxygen Activation by 2-D WO₃/TiO₂ Heterostructures

Abstract

Oxygen generation from the endogenous reaction and accompanying activation is of vital importance in ubiquitous environmental and biological catalysis. In this paper, we demonstrated the construction of sheet-on-sheet heterostructures for photocatalytic pure water splitting, which could simultaneously supply oxygen for molecular oxygen activation. Benefitted from the efficient charge separation between interconnected TiO 2 networks and faceted WO 3 nanoplates, our 2-D heterostructured photocatalysts exhibited 30-and 6-fold increased activity for pure water splitting than pristine WO 3 and TiO 2 , respectively. Under visible light irradiation, the oxygen generation rate of 178 μmol g −1 h −1 was even comparable to the scavenger-facilitated oxygen evolution reactions reported in the literatures. The type II band alignment was favorable for the selective reduction of oxygen molecules, generating more reactive oxygen species for organic pollutant degradation. These findings represent a promising way of self-supplying oxygen from pure water splitting for environmental and biological application.

Nano multi-layered HfO2/α-Fe2O3 nanocomposite photoelectrodes for photoelectrochemical water splitting

“…The negative shift in α - Fe 2 O 3 implies an increase in electron density, indicative of electron transfer from HfO 2 /α - Fe 2 O 3 . These shifts in binding energies are consistent with effective charge separation and electron transfer at the HfO 2 /α - Fe 2 O 3 heterojunction, enhancing the photocatalytic activity of the composite material [ 58 , 64 ]. Hence, it is possible to validate the successful fabrication of the HfO 2 /α - Fe 2 O 3 heterostructures film.…”

“…In Fig. 6 (b,c), the O1s spectra of the bare α - Fe 2 O 3 and HfO 2 /α - Fe 2 O 3 photoanodes are divided into three types of surface oxygen species [ 57 , 58 ]. These peaks are located at 529.65 eV, 531.09 eV and 532.98 eV which correspond to oxygen atoms lattice (O L ), oxygen vacancies (O v ), and adsorbed oxygen species (O c ), respectively.…”

Controlled synthesis of tungsten trioxide with globular clusters constructed of nanoplates by rapid breakdown anodization

“…Specifically, anodic oxidation of tungsten (W) has attracted wide scientific interest since it can easily fabricate WO 3 thin films on W substrate with various types of nanostructures for application in many advanced fields, such as dye-sensitized solar cells, photocatalysis/photoelectrocatalysis, gas sensors, and electrochromic device [3][4][5][6]. Although, the conventional anodization process of W is simpler compared to other methods such as hydrothermal [7,8] and sol-gel [9] for producing WO 3 , it is mainly efficient to prepare WO 3 thin films on the surface of W substrate metal [10]. Preparation and application of such an architecture are limited due to the following reasons: (a) the use of fluorides (NaF or NH 4 F) or hazardous organic solvents are often unavoidable in the synthetic process of conventional anodization, and (b) the opaque tungsten metal underneath a nanostructured film may influence the energy conversion of lightto-electrical or cause an electrical short-circuit when utilized in devices [11][12][13].…”

Hierarchical Ultrathin Layered GO-ZnO@CeO2 Nanohybrids for Highly Efficient Methylene Blue Dye Degradation

“…Water treatment has widespread research opportunities to limit this. Finding a simple, cost-effective and highly efficient route to eliminate industrial contaminants from wastewater is an exciting environmental research topic [1,2].…”