Coupling Piezocatalysis and Photocatalysis in Bi₄NbO₈X (X = Cl, Br) Polar Single Crystals

Abstract

Reactive oxygen species (ROS) as green oxidants are of great importance for environmental and biological applications. Photocatalysis is one of the major routes for ROS evolution, which is seriously restricted by rapid charge recombination. Herein, piezocatalysis and photocatalysis (i.e., piezo–photocatalysis) are coupled to efficiently produce superoxide radicals (•O2−), hydrogen peroxide (H2O2), and hydroxyl radicals (•OH) via oxygen reduction reaction (ORR), by using Bi4NbO8X (X = Cl, Br) single crystalline nanoplates. Significantly, the piezo‐photocatalytic process leads to the highest ORR performance of the Bi4NbO8Br nanoplates, exhibiting •O2−, H2O2, and •OH evolution rates of 98.7, 792, and 33.2 µmol g−1 h−1, respectively. The formation of a polarized electric field and band bending allows directional separation of charge carriers, promoting the catalytic activity. Furthermore, the reductive active sites are found enriched on all the facets in the piezo–photocatalytic process, also contributing to the ORR. By piezo–photodeposition of Pt to artificially plant reductive reactive sites, the Bi4NbO8Br plates demonstrate largely enhanced photocatalytic H2 production activity with a rate of 203.7 µmol g−1 h−1. The present work advances piezo–photocatalysis as a new route for ROS generation, but also discloses the potential of piezo–photocatalytic active sites enriching for H2 evolution.

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

“…For example, the generation rate of ROS on Bi 4 NbO 8 Br nanoplates under simultaneous irradiation of visible light and ultrasound has been shown to far exceed that under individual irradiation. [ 31 ] In that study, the enhancement was attributed to band bending that was enabled by the polarization field, which in turn accelerated the photoexcited charge separation. Band bending has historically been used to explain phenomena occurring on metal‐semiconductor interfaces [ 32 ] but also increasingly to explain how changes in electronic structures of heterogeneous materials may change the thermal sorption of reactants and products and the involved reaction and mass transport processes.…”

Modulating electron density of vacancy site by single Au atom for effective CO2 photoreduction

“…Photocatalytic CO 2 conversion technology has attracted extensive interest, since the conversion of CO 2 into high value-added chemicals could potentially be achieved under relatively mild conditions, which facilitates its resource utilization 3,4 . Generally, photocatalytic CO 2 conversion is a typical photoreduction reaction, which needs electrons to participate in [5][6][7] . Different from other photoreduction reactions, such as hydrogen evolution reaction (two electrons), photocatalytic CO 2 conversion is an inherently multi-electron reduction process [8][9][10] .…”

A Sonosensitizer-based Polymeric Nanoplatform for Realizing Chemo-sonodynamic Combination Therapy of Lung Cancer 

“…While both NC-NPs and C-NPs exhibited good stability with zeta potential of -28.9 mV and − 30.9 mV, respectively ( Table 1). In addition, the 1 H-NMR, 13 C-NMR and FT-IR results of CS-ADH-Rh-LA were shown in Fig. S2.…”

“…Previously, SSs like protoporphyrin IX (PpIX) [10], hematoporphyrin monomethyl ether (HMME) [11], chlorin e6 (Ce6) [12], titanium dioxide (TiO 2 ) [13] and Silicon-based [14] nanoparticles have all been investigated to produce ROS for tumor inhibition [15,16], while these commonly used SSs were expensive and possessed SDT property only under ultrasonic condition. To overcome those di culties, Rhein (Rh) was initially discovered to possess the SDT property in this work.…”