Reactive Oxygenated Species Generated on Iodide‐Doped BiVO₄/BaTiO₃ Heterostructures with Ag/Cu Nanoparticles by Coupled Piezophototronic Effect and Plasmonic Excitation

Abstract

An effective generation of reactive oxygen species (ROS) is of interest from the perspective of environmental technology and industrial chemistry, and here piezocatalysis and photocatalysis using heterostructures based on iodide‐doped BiVO4/BaTiO3 with photodeposited Ag or Cu nanoparticles (BiVO4:I/BTO‐Ag or BiVO4:I/BTO‐Cu) is studied. The generation rates of •OH and •O2− radicals over BiVO4:I/BTO‐Ag during piezophotocatalysis are 371 and 292 µmol g−1 h−1, respectively, and significantly higher than those of sole piezocatalysis and photocatalysis. These rates are among the highest reported for the production of free radicals with the piezophototronic effect. Among the catalysts, BiVO4:I/BTO shows the highest reactivity for the production of H2O2 in piezocatalysis (with a concentration of 468 µm after 100 min of irradiation, and still constantly increasing). On BiVO4:I/BTO‐Ag and BiVO4:I/BTO‐Cu, it seems that redundant electrons and holes had reacted effectively with the generated H2O2 and in turn had reduced their activities; however, the amounts of H2O2 that are formed on BiVO4:I/BTO‐Ag or BiVO4:I/BTO‐Cu under piezophotocatalysis are superior to those of individual piezocatalysis and photocatalysis. A piezophototronic coupling via an ultrasound‐mediated and piezoelectric‐based polarization field and photoexcitation accounting for the enhanced photocatalytic activity of the iodine‐doped heterostructures with plasmonically sized Ag or Cu nanoparticles is suggested.

High Performance Generation of H2O2 under Piezophototronic Effect with Multi‐Layer In2S3 Nanosheets Modified by Spherical ZnS and BaTiO3 Nanopiezoelectrics

“…It is clear that the redox reactions of Mn 2+ cations are occur preferentially at the ZnS, BTO, and In 2 S 3 interfaces under visible light and/or ultrasound irradiation (see Figure S19a,c,e, Supporting Information), this is because the contact interfaces behave as active sites are prone to accumulate electrons and holes, which are also observed at the interfaces of anatase/rutile TiO 2 [ 32 ] and iodine‐doped BiVO 4 /BaTiO 3 . [ 33 ] The surfaces of In 2 S 3 are almost unchanged during piezo‐, photo‐, and piezophotocatalytic reactions, which further illustrates the Mn 2+ cations deposited at the interfaces of ZnS, BTO, and In 2 S 3 . In addition, the binding energies of Mn 2p in XPS spectra in piezo‐ and photocatalytic processes show the manganese species are mainly composed of MnO x and metallic Mn (Figure S19b,d, Supporting Information), while the manganese species consist of metallic Mn in piezophotocatalytic processes (Figure S19f, Supporting Information), where x is between 1.5 and 2.0 because the observed binding energies of manganese oxides are between those of Mn 2 O 3 and MnO 2 .…”

Flexoelectric Domain Walls Originated from Structural Phase Transition in Epitaxial BiVO4 Films

“…[ 33 ] Beside, tuning oxidation/reduction of V OV 5+ / V OV 4+ states in BVO [ 34 ] or modulation of oxygen vacancy by hybrid structure [ 35 ] provides insights to modify carrier trapping/extracting procedure. In addition, ferroelectric‐semiconductor hybrid (Iodide‐doped BiVO 4 /BaTiO 3 ) [ 36 ] could also be applied to piezophototronic field, which is an coupling effect between photoexcitation and piezopotential. Aside from recent studies, this work systematically investigates polar domain walls unforeseen from its symmetry, revealing that the flexoelectricity originated from domain walls could possibly endow a flexopotential for charge transport.…”

Structure/Property Control in Photocatalytic Organic Semiconductor Nanocrystals

“…Besides the role of electron trapping, the surface plasmon resonance (SPR) effect of Au or Ag NPs makes them excellent light‐trapping enhancers with resonantly adjusted plasmon coupling for enhancing the photocatalytic efficiency. [ 112 ] For example, layered nanostructures of several organic dyes, including ruthenium tetra(15‐crown‐5)‐phthalocyaninate derivative RuL(EIN) 2 , 5‐carboxytetramethylrhodamine (TAMRA), cerium bis[tetra‐(15‐crown‐5)‐phthalocyaninate] (CeL 2 ) and N,N 0 ‐bis(3‐pentyl)perylene‐3,4,9,10‐bis(dicarboximide) (EP‐PDI), which were coated by gold aggregates with a tunable structure. Different from the previous strategies that adopted chemistry, size or shape control to modify the optical properties of plasmonic metals, here a real‐time control of the spatial arrangement and interaction between Au NPs and organic films during Au NP deposition ( Figure a–d) yielded a more than 500% enhancement of their absorption in a wide range of wavelengths (520–660 nm, Figure 18e–j).…”