A tetragonal tungsten bronze-type photocatalyst: Ferro-paraelectric phase transition and photocatalysis

Recent Advances of Ferro-, Piezo-, and Pyroelectric Nanomaterials for Catalytic Applications

“…69 Inspired by these works, photocatalytic organic dye degradation and water splitting for H 2 production using ferroelectric nanomaterial powders (e.g., BaTiO 3 , K x Na 1 − x NbO 3 , and Sr 0.7 Ba 0.3 Nb 2 O 6 ) were investigated. [65][66][67]70,71 In addition, the relationship between the ferroelectricity and photocatalytic activity at the nanoscale was revealed. The accumulation of electrons on the positively charged surface gives rise to downward band bending and holes on the negatively charged surface results in upward band bending.…”

“…Similarly, investigation of Sr 0.7 Ba 0.3 Nb 2 O 6 possessing a low transition temperature (65 °C) from the ferro-to paraelectric phase also confirmed that H 2 can only be generated from water by the ferroelectric phase. 71 Despite these achievements, enhancement of the photocatalytic efficiency by modulating the ferroelectric potential of powder samples remains a great challenge. Because of the difficulty of depositing an electrode on the nanopowders, it is hard to pole ferroelectric nanomaterials using a conventional method.…”

The Role of Polarization in Photocatalysis

“…In ah eterostructured piezo-photocatalyst, the piezopotential-induced polarization electric field can be generated from the piezoelectric component under either stress or strain. Given the intimate interfacial interaction and Fermi 1.65 10 À2 ppm J À1 degradation of SMX [34] Angewandte Chemie Kurzaufsätze energy equilibration, band bending drives the surviving photoexcited charge carriers on the surface of the photocatalytic component in opposite directions,achieving efficient interfacial charge separation between different components. [35] As at ypical piezoelectric material, ZnO is employed to capture mechanical energy and provides ap iezoelectric polarization field in heterojunctions.In2016, Wang et al revealed the potential of piezotronics in photocatalysis on account of the research of polarization-induced interface band bending by assembling TiO 2 nanoparticles onto ZnO nanoplatelets.…”

Enhanced Piezocatalytic Activity of Sr0.5Ba0.5Nb2O6 Nanostructures by Engineering Surface Oxygen Vacancies and Self-Generated Heterojunctions

“…In recent years, lead-free oxides with tungsten–bronze (TB) structures have attracted widespread attention because of their outstanding pyroelectric, piezoelectric, electro-optic, and photorefractive properties, − demonstrating promising potential applications in the fields of optics and electronics. Among them, Sr 0.5 Ba 0.5 Nb 2 O 6 (SBN), which belongs to the P 4 bm space group, possesses superior piezoelectric and pyroelectric properties. ,− In SBN, only 180° ferroelectric polarization domains can be formed, making it highly suitable for separating and transporting electrons and holes in opposite directions .…”