Piezodeposition of Metal Cocatalysts for Promoted Piezocatalytic Generation of Reactive Oxygen Species and Hydrogen in Water

Abstract

Piezocatalysis in aqueous medium has shown great potential for various applications, however the efficiency of piezocatalytic nanoparticles is harmed by the limited utilization of piezoelectric charge and the lack of active catalytic interface. In this study, BaTiO3@Metal (BTO@M, M=Pt, Pd and Au) hetero‐nanostructures were synthesized by using a piezodeposition method. The deposited metal cocatalysts significantly promote the separation and migration of piezogenerated charge, consequently enhancing the piezocatalytic reactions on different metal cocatalyst interfaces. Specifically, BTO@Au under ultrasonic vibrations exhibited most efficient generation of reactive oxidative species via a two‐electron reduction pathway in the presence of dissolved oxygen, while BTO@Pt showed promoted hydrogen evolution in the absence of oxygen. The metal‐piezoelectric hetero‐nanostructures proposed in this work highlight the key role of noble metal as cocatalysts for piezoelectricity‐driven oxygen reduction and hydrogen evolution reactions, which could further advance piezocatalysis in the field of clean energy, water disinfection and biomedicine.

Surface-Confined Piezocatalysis Inspired by ROS Generation of Mitochondria Respiratory Chain for Ultrasound-Driven Noninvasive Elimination of Implant Infection

“…28−30 In our previous study, BTO@Au exhibited the most efficient generation of reactive oxidative species under ultrasonic vibrations when compared to BTO@Pt and BTO@Pd. 31 Therefore, BTO NPs with a diameter of about 200 nm were embedded into the PCL surface by a simple polymer casting method, and then the BTO NPs were decorated with Au cocatalysts by an in situ piezo-deposition process to finally obtain the piezoPCL film (Figure 1a). The pristine crystalline BTO NPs possess typical perovskite phase structure (Figure S1).…”

“…Under mechanical stimulation, piezoelectric electrons generated from the stressed BTO NPs can be transferred to the deposited Au cocatalysts with a high work function, leading to efficient charge separation. With the aid of Au cocatalysts, the discharged electrons will then react with H 2 O and dissolved O 2 in surrounding medium to produce superoxide anions (•O 2 − ), hydroxyl radicals (•OH), and other ROS species 31 (Figure 2a). Total ROS production of PCL and piezoPCL(x) samples were detected, as shown in Figure 2b, and with the increase of the BTO NP loading, the ROS generation capacity was gradually enhanced with the increase of the ultrasonic irradiation time.…”

“…To construct the piezoelectric surface, we chose polycaprolactone (PCL) as the polymer substrate and typical perovskite barium titanate nanoparticles (BTO NPs) as piezocatalysts. Loading high-work function noble metal NPs on piezoelectric substrates is believed to be an effective way to promote charge separation and enhance the piezocatalytic performance. − In our previous study, BTO@Au exhibited the most efficient generation of reactive oxidative species under ultrasonic vibrations when compared to BTO@Pt and BTO@Pd . Therefore, BTO NPs with a diameter of about 200 nm were embedded into the PCL surface by a simple polymer casting method, and then the BTO NPs were decorated with Au cocatalysts by an in situ piezo-deposition process to finally obtain the piezoPCL film (Figure a).…”

Piezoelectric Nanostructured Surface for Ultrasound‐Driven Immunoregulation to Rescue Titanium Implant Infection

“…The results suggested that •OH, •O 2− , and 1 O 2 were the main oxidative species produced by piezocatalysis from piezoTi, which was similar to other BTO-based piezocatalysis. [16,27,28] The oxidative radicals were also identified by the electron spin resonance (ESR) spectra (Figure S9, Supporting Information). The promoted ROS generation ability of piezoTi was ascribed to the efficient charge separation on the piezotronic surface and Au cocatalyst-assisted oxygen reduction reactions [28] (Figure 2i), which suggested potential piezodynamic therapy capability.…”

Reactive oxygen species for therapeutic application: Role of piezoelectric materials

“…This media is generally considered to be water which is abundant in all cell tissues. 97 In the presence of ultrasound, there develops a large number of vapour-filled bubbles which experience a quasiadiabatic collapse and create an elevated pressurized atmosphere. 98,99 Elimination of system pressure results in molecular deformation or structural distortion, which can be a reason for the implementation of a local dipole moment.…”