Search query: piezocatalysis

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abstract: Piezoelectric semiconductor based piezocatalysis has emerged as a promising approach for converting mechanical energy into chemical energy for renewable hydrogen generation and wastewater treatment under the action of mechanical vibration. Similar to photocatalysis, piezocatalysis is triggered by the separation, transfer, and consumption of piezo generated electrons and holes. Inspired by this, herein, we report that the cocatalyst, which is widely used in photocatalysis, can also improve the semiconductor based piezocatalytic properties. In the proof of concept design, well defined Pd as a model cocatalyst has been deposited on the surface of piezoelectric BiFeO3 nanosheets, which not only facilitates the separation of charge carriers by accepting the piezoelectrons from BiFeO3 but also lowers the activation energy/overpotential through supplying highly active sites for the proton reduction reaction. Consequently, the as obtained hybrid piezocatalyst delivers a high H2 evolution rate of 11.4 mmol h 1 (10 mg of catalyst) 19.0 times as high as that of bare BiFeO3. The band tilting induced by the piezoelectric potential is proposed to lower or eliminate the Schottky barrier and smooth the electron transfer from BiFeO3 to Pd, while the exposed facet, domain size, and loading amount of Pd cocatalyst are proved to be the key parameters determining the ultimate piezocatalytic activity. Our work provides some enlightenment on advancing the design and fabrication of more efficient piezocatalysts for H2 evolution based on rational engineering on the cocatalyst.
author_names: Guodong Yang

Weijun Wang

Shijie Wu

Binjia Gao

Yanbo Xu

Zheng Chen

Shuxian Zhong

Jianrong Chen

Song Bai
title: Cocatalyst Engineering in Piezocatalysis: A Promising Strategy for Boosting Hydrogen Evolution.
venue: ACS applied materials interfaces
year: 2021

abstract: Piezocatalysis, converting mechanical vibration into chemical energy, is an emerging technology to address environmental issues. In this work, we propose an efficient method to significantly improve the piezocatalytic activity by morphology engineering rather than composition design. The catalytic property in BaTiO3 nanocrystallites with diverse morphologies is investigated by dye degradation and hydrogen production under ultrasonic vibration. The BaTiO3 nanosheets exhibit an excellent piezocatalytic activity with a degradation rate of 0.1279 min 1 for Rhodamine B, far beyond those in previous piezocatalytic literature and even comparable to excellent photocatalysts, and also a high hydrogen production rate of 92 mmol g 1 h 1. Compared with nanowires and nanoparticles, the 2D morphology greatly enhances the piezocatalytic activity in nanosheets owing to much larger piezoelectric potential. This proves that the piezocatalytic property is dominated by the morphology dependent piezoelectricity, rather than specific surface area as other catalysis. Dominated by bending vibrating mode, the piezocatalytic activity reaches a maximum at the piezoelectric resonating frequency, and it increases with the ultrasonic power. Moreover, it has good reusability and wide versatility for catalytic degradation. This work gives an in depth understanding of piezocatalytic mechanism and provides a way to develop high performance and eco friendly piezocatalysts.
author_names: Chengye Yu

Meng Xi Tan

Chuanbao Liu

Ruowei Yin

Hui-min Meng

Yanjing Su

Lijie Qiao

Yang Bai
title: Ultrahigh piezocatalytic capability in eco friendly BaTiO3 nanosheets promoted by 2D morphology engineering.
venue: Journal of colloid and interface science
year: 2021

abstract: Abstract The polarization field with the function in carrier separation has aroused substantial interest. For heterojunction complexes, however, the static polarization field will be inevitably shielded by a large number of carriers. Herein, a novel hybrid consisted of single domain PbTiO3 coated by CdS particles was selected as a model material to prove that the alternating piezoelectric field induced by periodic stress can destroy shielding effect. After the introduction of alternating piezoelectric potential by using ultrasonication, PbTiO3/CdS 10 exhibited a much higher H2 production rate by piezo photocatalysis (849.0 mmol h 1 g 1) than by individual piezocatalysis (400.6 mmol h 1 g 1) or photocatalysis (98.9 mmol h 1 g 1) Furthermore, the finite element simulation shows that PbTiO3/CdS heterostructure has a superior piezoelectric potential difference compare to pure PbTiO3 or pure CdS. Based on data analysis, the mechanism about the piezo photo coupling effect was proposed, which will provide a reference for the design and development of high efficiency piezo photocatalyst.
author_names: Xueyan Huang

Rui Lei

Jie Yuan

Fan Gao

Cankun Jiang

Wenhui Feng

Jiandong Zhuang

Ping Liu
title: Insight into the piezo photo coupling effect of PbTiO3/CdS composites for piezo photocatalytic hydrogen production
year: 2021

abstract: Piezocatalysis is a promising approach for environmental pollutant removal. Monoclinic dibismuth tetraoxide (m Bi2O4) was first applied to piezocatalyze organics under ultrasonic vibration. The built in electric field with ultrasonic stress drives the separation of holes and electrons in m Bi2O4. Its excellent piezocatalytic activity, reusability and chemical stability make m Bi2O4 a new candidate of piezocatalysis.
author_names: Fengling Liu

Haoxuan Chen

Chenmin Xu

Linlin Wang

Pengxiang Qiu

Shuo Gao

Jiawei Zhu

Shuai Zhang

Zhaobing Guo
title: Monoclinic dibismuth tetraoxide (m Bi2O4) for piezocatalysis: new use for neglected materials.
venue: Chemical communications
year: 2021

abstract: Piezocatalysis provides a promising strategy for directly converting weak mechanical energy into chemical energy. In this work, we report a simple one step hydrogen reduction route for the simultaneous generation of surface defects and heterojunctions in Sr0.5Ba0.5Nb2O6 nanorods fabricated by a molten salt synthesis method. The as fabricated Sr0.5Ba0.5Nb2O6/Sr2Nb2O7 nanocomposites with controllable oxygen vacancies exhibited excellent piezocatalytic activity under ultrasonic vibration, with an about 7 times enhancement of the rate constant (k 0.0395 min 1) for rhodamine B degradation and an about 10 times enhancement of the water splitting efficiency for hydrogen generation (109.4 mmol g 1 h 1) for the optimized sample (H2 annealed at 500 degC) compared to pristine Sr0.5Ba0.5Nb2O6 nanorods. This work demonstrates the essential role of a well modulated oxygen vacancy concentration in the piezocatalytic activity and provides an inspiring guide for designing self generated heterojunction piezocatalysts.
author_names: Jianqing Dai

Ningning Shao

Suwei Zhang

Zhicheng Zhao

Yangke Long

Shiyin Zhao

Shun Li

Cui-hua Zhao

Zuotai Zhang

Weishu Liu
title: Enhanced Piezocatalytic Activity of Sr0.5Ba0.5Nb2O6 Nanostructures by Engineering Surface Oxygen Vacancies and Self Generated Heterojunctions.
venue: ACS applied materials interfaces
year: 2021

abstract: Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZTO) ferroelectric ceramic loaded with Ag nanoparticles (NPs) was explored for its photo/piezocatalytic performance. The presence of Ag loading on BCZTO ceramic was confirmed using electron microscopes. X ray photoelectron spectroscopy revealed the metallic chemical state of Ag NPs loaded on the surface of BCZTO ceramic. The absorbance spectrum of the Ag loaded BCZTO sample showed a visible light absorption hump due to the phenomenon of surface plasmonic resonance. During the photocatalysis process, the [Formula: see text]99% of rhodamine B (RB) dye was degraded in aqueous solution using the Ag loaded BCZTO sample, showing its promising photocatalysis activity. During the piezocatalysis process, the [Formula: see text]95% of RB dye was degraded using the Ag loaded BCZTO sample, showing its promising piezocatalytic activity. The *OH radical species were found responsible for the photocatalytic and piezocatalytic performance. The photo/piezocatalytic performance was found to be consistent over five cycles, indicating promising reusability of the Ag loaded BCZTO sample.
author_names: Moolchand Sharma

Gurpreet J Singh

Rahul Vaish
title: Ag nanoparticles loaded Ba0.85Ca0.15Ti0.9Zr0.1O3 for multicatalytic dye degradation.
venue: Nanotechnology
year: 2021

abstract: Abstract The cascading of methane valorization and methanol upgrade, both of which are important in C1 chemistry, becomes a promising strategy to fabricate value added chemicals from methane directly. Reconciling the contradiction between the C H bond activation of methane and the over oxidation susceptibility of methanol is critical but challenging. Herein, we report the piezocatalytic methane conversion over hydroxyapatite (HAp) under ultrasonic vibration at ambient conditions, obtaining alcohols as liquid products without any sign of CO or CO2. Mechanistic studies reveal that the piezocatalytic effect of HAp drives H2O and methane activation and supplies hydroxyl radical *OH) to attack the methane C H bond, while the ultrasonic induced negative surface charge (SC) promotes methanol dehydration into methyl carbene as a fascinating C1 building block to facilitate product upgrade into C2 and C3 alcohols. Attributing to the enriched SC which tunes the surface acid base property, piezocatalysis presents a new approach for C C coupling.
author_names: Yuanyi Zhou

Haipeng Wang

Xuechen Liu

Simeng Qiao

Dengkui Shao

Jing Zhou

Longyan Zhang

Wenzhong Wang
title: Direct piezocatalytic conversion of methane into alcohols over hydroxyapatite
year: 2021

abstract: Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZTO) ferroelectric ceramic loaded with Ag nanoparticles (NPs) was explored for its photo/piezocatalytic performance. The presence of Ag loading on BCZTO ceramic was confirmed using electron microscopes. X ray photoelectron spectroscopy revealed the metallic chemical state of Ag NPs loaded on the surface of BCZTO ceramic. The absorbance spectrum of the Ag loaded BCZTO sample showed a visible light absorption hump due to the phenomenon of surface plasmonic resonance. During the photocatalysis process, the 99% of rhodamine B (RB) dye was degraded in aqueous solution using the Ag loaded BCZTO sample, showing its promising photocatalysis activity. During the piezocatalysis process, the 95% of RB dye was degraded using the Ag loaded BCZTO sample, showing its promising piezocatalytic activity. The *OH radical species were found responsible for the photocatalytic and piezocatalytic performance. The photo/piezocatalytic performance was found to be consistent over five cycles, indicating promising reusability of the Ag loaded BCZTO sample.
author_names: Moolchand Sharma

Gurpreet J Singh

Rahul Vaish
title: Ag nanoparticles loaded Ba0.85Ca0.15Ti0.9Zr0.1O3 for multicatalytic dye degradation
venue: Nanotechnology
year: 2020

abstract: Abatract Photocatalysis technology has been proved to be a potential strategy for removal of organic dyes, however high power light sources are generally necessary to initiate photocatalytic reaction. In this work, we employed an excellent photocatalyst of Bi2WO6 with visible light harvest and meanwhile an intrinsic ferroelectricity, which realized the efficient degradation of organic dye via the synergetic photopiezocatalysis. Through coupling the illumination by a low power (9 W) LED and the ultrasonic vibration (120 W) by an ultrasonic cleaner, the nanoflower like Bi2WO6 composed of ultrathin nanosheets showed a much more enhanced photopiezocatalysis performance for purification of organic dye than the individual photocatalysis and piezocatalysis. Furthermore, the high mineralization efficiency and the good durability of the Bi2WO6 catalyst were demonstrated. The possible mechanism of photopiezocatalysis was finally proposed, where the ultrasound induced piezoelectric field in Bi2WO6 drove photo generated electrons and holes to diffuse along opposite directions, consequently promoting the separation efficiency of charge carriers. This work indicates that the synergetic photopiezocatalysis by coupling irradiation and ultrasonic vibration is a promising strategy to purify organic pollutants in wastewater.
author_names: Hua Lei

Meixuan Wu

Y Liu

Fan Mo

Jiayao Chen

Shilong Ji

Yan Zou

Xiaoping Dong
title: Built in piezoelectric field improved photocatalytic performance of nanoflower like Bi2WO6 using low power white LEDs
venue: Chinese Chemical Letters
year: 2021

abstract: Abstract Excellent vibration electricity conversion in various piezoelectric materials is frequently restricted, thus hardly generates high mechanochemical potential eliciting by ferroelectric polarization for advanced catalysis processes. Herein, we propose a phase boundary in Li modified Na0.5K0.5NbO3 (NKN) materials to improve the piezocatalytic activity, and the relationships among the composition, phase structure, electrochemical and catalytic performances were systematically investigated. An outstanding piezocatalytic performance was exhibited in the LNKN6 (6 mol Li doped NKN) with coexistence of orthorhombic and tetragonal phases, and the piezocatalytic activity showed a superior repeatability and universal applicability for the degradation of organic pollutants. The reaction rate constant of the LNKN6 was up to 25.16 x 10 3 min 1, which was 3.20 times than that of pristine NKN. The enhancement of piezocatalytic activity was confirmed by Landau Ginsburg Devonshire phenomenological theory and the transfer efficiency of force generated electrons and holes, and then an appropriate mechanism of the ultrasonic vibration driven piezocatalysis was speculated. This work provides an alternative strategy to enhance the catalytic efficiency of piezocatalyst and the high activity of the NKN based piezoelectrics has an important application for environmental remediation.
author_names: An Shan Zhang

Zhiyong Liu

Bing Xie

Jinshan Lu

Kun Guo

Shanming Ke

Longlong Shu

Huiqing Fan
title: Vibration catalysis of eco friendly Na0.5K0.5NbO3 based piezoelectric: An efficient phase boundary catalyst
year: 2020