Piezoelectric Field Research Articles

Coexistence of Large In-Plane and Out-of-Plane Piezoelectric Response in Group III–VI XMAY2 (X = I; M = Ti, Zr; A = Al, Ga; Y = S, Se) Monolayers

Flexible materials with both in-plane and out-of-plane piezoelectric coefficients are needed in the development of advanced nanoelectromechanical systems. However, the challenge is to find flexible materials with the coexistence of in-plane and -out-of-plane piezoelectric responses, which hinders the progress of high-performance piezoelectric sensor development. In this paper, we propose the flexible XMAY2 (X = I; M = Ti, Zr; A = Al, Ga; Y = S, Se) monolayers, which belong to the group III-VI XMAY2 family, which showcase notable in-plane and out-of-plane piezoelectric coefficients. The in-plane (d11) and out-of-plane (d31) piezoelectric coefficients of the XMAY2 monolayers vary from 5.20 to 7.04 pm/V and from −0.23 to 0.48 pm/V, respectively. The large in-plane and out-plane piezoelectric responses coexist (d11 = 7.04 pm/V; d31 = 0.48 pm/V) in the IZrGaS2 monolayer, which is larger than other materials in the XMAY2 family, such as SMoSiN2 (d11 = 2.51; d31 = 0.28 pm/V). In addition, the mechanical and transport properties of XMAY2 demonstrate its impressive flexibility characteristics as well as its efficient electrical conductivity. Due to inversion symmetry breaking in both atomic structure and charge distribution of XMAY2 monolayers, the group III-VI XMAY2 family exhibits a potentially rich scope of applications in the field of piezoelectricity.

Insight into interfacial engineering for enhancing the synergistic effect of piezo-photocatalytic hydrogen peroxide production

Constructing heterojunctions represents a prevalent approach for enhancing piezo-photocatalytic performance. However, it remains challenging due to contradictory charge polarity and a poor active site. In this study, we employed an in situ hydrothermal method to fabricate a ZnIn2S4-BiOCl compact heterojunction with interfacial chemical bonding. Experimental and theoretical calculations demonstrate that the interfacial chemical bond (Bi-S bond) creates a strong interfacial electronic effect between the heterojunctions, acting as strain centers and charge transfer channels to enhance coordinated piezoelectric and photoelectric fields, thereby facilitating charge transfer. Additionally, interfacial bonding induces dynamic surface reconstruction and redistribution of electron density, improving reactant activation and charge exchange while reducing reaction barriers. Consequently, ZB-4 catalyst exhibits exceptional piezoelectric photocatalytic performance for pure water to H2O2 conversion (1987.33 μmol g-1·h-1), which is 5.85 times than that of pure BiOCl. This study presents a valuable strategy for enhancing positive coordination between heterojunctions and the photocatalytic piezoelectric effect.

Ultrasonic-driven degradation of organic pollutants using piezoelectric catalysts WS2/Bi2WO6 heterojunction composites

Water pollution has been made worse by the widespread use of organic dyes and their discharge, which has coincided with the industry's rapid development. Piezoelectric catalysis, as an effective wastewater purification method with promising applications, can enhance the catalyst activity by collecting tiny vibrations in nature and is not limited by sunlight. In this work, we designed and synthesized intriguing WS2/Bi2WO6 heterojunction nanocomposites, investigated their shape, structure, and piezoelectric characteristics using a range of characterization techniques, and used ultrasound to accelerate the organic dye Rhodamine B (RhB) degradation in wastewater. In comparison to the pristine monomaterials, the results demonstrated that the heterojunction composites demonstrated excellent degradation and stability of RhB under ultrasonic circumstances. The existence of heterojunctions and the internal piezoelectric field created by ultrasonic driving work in concert to boost catalytic performance, and the organic dye's rate of degradation is further accelerated by the carriers that are mutually transferred between the composites.

Piezoelectric Analgesia Blocks Cancer-Induced Bone Pain.

The manipulation of cell surface receptors' activity will open a new frontier for drug development and disease treatment. However, limited by the desensitization of drugs, effective physical intervention strategy remains challenging. Here, the controllable internalization of transient receptor potential vanilloid 1 (TRPV1) on neural cells by local piezoelectric field is reported. Single-cell-level local electric field is construct by synthesizing piezoelectric BiOIO3 nanosheets (BIONSs). Upon a mild ultrasound of 0.08Wcm-2, an electric field of 15.29µV is generated on the surface of BIONSs, further inducing TRPV1 internalization in 5min. The as-downregulated TRPV1 expression results in the reduction of Ca2+ signal in a spinal neuron and the inhibition of the activity of wide range dynamic neurons, therefore effectively preventing the transmission of cancer-induced bone pain (CIBP). This strategy not only charts a new course for CIBP alleviation, but also introduces a promising nanotechnology for regulating cell surface receptors, showing significant potential in neuropathological and receptor-related diseases.

All-Organic Piezo-Photocatalytic Film with Highly Efficient Catalysis, Weak-Force Excitation, and Recyclability.

Polyaniline (PANI), a typical organic photocatalyst, has an adjustable structure and good stability, can be easily synthesized on a large scale, and is economical. PANI is doped with ions to regulate its internal structure and improve its photocatalytic performance. However, its photocatalytic performance is limited by the doping concentration and its intrinsic properties, hindering its further application. Herein, PANI films with a piezo-photocatalytic function are fabricated to improve photocatalytic performance and explore their self-powered environmental purification property. PANI/poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) sandwich films, with PVDF-HFP as the interlayer, are prepared by introducing a piezoelectric field into PANI photocatalysts, thereby achieving excellent piezo-photocatalytic performance. The as-fabricated piezo-photocatalyst degrades methyl orange at a rate of 91.2% after 60min under magnetic stirring. Owing to the low Young's modulus of the all-organic catalyst, self-powered purification is realized using the PANI/PVDF-HFP film. Leaf surfaces are functionalized by loading the film in them for removing pollutants under sunlight and water flow. Thus, this study proposes a common strategy, wherein a piezoelectric interlayer is introduced to load the organic photocatalyst for preparing an all-organic piezo-photocatalyst. This piezo-photocatalyst can be easily recycled and responds to weak forces, realizing its application for self-powered environmental purification.

Synthesis of strongly interactive FeWO4/BiOCl heterostructures for efficient photoreduction of CO2 and piezo-photodegradation of bisphenol A

Development of multi-functional photocatalysts for CO2 reduction and pollutant elimination is practically significant for solving the environmental problems and energy shortages. In this study, we have immobilized FeWO4 (FWO) nanoparticles on the surface of (001)-facet-exposed BiOCl (BOC) nanosheets through their strong electrostatic interaction to form FWO/BOC heterojunctions. Experimental and theoretical studies corroborate that the FWO/BOC heterojunctions exhibit high-efficiency Z-scheme transfer and separation of photocarriers, and possess excellent photocatalysis for CO2 reduction and bisphenol A (BPA) degradation. Under simulated-sunlight irradiation, the 9 %FWO/BOC heterojunction exhibits a photoreduction performance with CH4/CO yield rates of 4.25/9.41 μmol g−1 h−1 (5 h reaction), which are 3.86/5.26 times higher than those for bare BOC; whereas its photodegradation performance (η(60 min) = 66.8 %, kapp = 0.01755 min−1) is enhanced by 4.3 and 2.7 times compared with that of bare FWO and BOC, respectively. Furthermore, when ultrasonic vibration is simultaneously employed during the simulated-sunlight illumination, the ultrasonic-induced piezoelectric polarization field in BOC nanosheets accelerates the bulk photocarrier separation, resulting in a further improvement in the BPA degradation, and the calculated SF = 1.79 quantifies the degree of enhancement achieved by piezo-photocatalysis collaboration. The introduction of a moderate amount of H2O2 or peroxymonosulfate (PMS) in the reaction solution plays a significant role in promoting the BPA degradation due to the generation of additional •OH and •SO4− reactive species. The mechanisms for photocatalytic CO2 reduction and piezo-photodegradation of BPA catalysis were deeply studied by combining experiments and theory.

Enhancing the piezocatalytic performance for H2 evolution by constructing BiOCl/UiO-66 heterostructure

Developing highly efficient piezocatalytic system for hydrogen production is crucial in addressing the current energy crisis. Herein, we synthesized BiOCl/UiO-66 heterostructure piezocatalyst using facile one-step solvothermal method and evaluated its performance for piezocatalytic H2 evolution under ultrasonic vibration. Our findings reveal that BiOCl/UiO-66 heterostructure demonstrates excellent catalytic activity, yielding high piezocatalytic H2 evolution rate of 650.9 μmol g−1 h−1, significantly surpassing that of pure BiOCl (176.5 μmol g−1 h−1) and UiO-66 (352.6 μmol g−1 h−1). Furthermore, the BiOCl/UiO-66 presents good stability throughout cyclic experiments. The improved catalytic performance of BiOCl/UiO-66 is mainly attributed to the formation of heterostructure, which can induce more active sites and the strong piezoelectric field that aids in charge carriers separation. A possible mechanism of BiOCl/UiO-66 heterostructure is proposed. This work offers practical approach to boost the hydrogen production efficiency of Bi-based piezocatalyst.

A first-principles prediction of novel Janus ZrGeZ3H (Z = N, P, and As) monolayers: Raman active modes, piezoelectric responses, electronic properties, and carrier mobility.

In this article, an attempt is made to explore new materials for applications in piezoelectric and electronic devices. Based on density functional theory calculation, we construct three Janus ZrGeZ3H (Z = N, P, and As) monolayers and study their stability, piezoelectricity, Raman response, and carrier mobility. The results from phonon dispersion spectra, ab initio molecular dynamics simulation, and elastic coefficients confirm the structural, thermal, and mechanical stability of these proposed structures. The ZrGeZ3H monolayers are indirect band gap semiconductors with favourable band gap energy of 1.15 and 1.00 eV for the ZrGeP3H and ZrGeAs3H, respectively, from Heyd-Scuseria-Ernzerhof functional method. It is found that the Janus ZrGeZ3H monolayers possess both in-plane and out-of-plane piezoelectric coefficients, revealing that they are potential piezoelectric candidates. In addition, the carrier mobilities of electrons and holes along transport directions are anisotropic. Notably, the ZrGeP3H and ZrGeAs3H monolayers have high electron mobility of 3639.20 and 3408.37 cm2 V-1 s-1, respectively. Our findings suggest the potential application of the Janus ZrGeZ3H monolayers in the piezoelectric and electronic fields.

Visualizing and Controlling of Photogenerated Electron-Hole Pair Separation in Monolayer WS2 Nanobubbles under Piezoelectric Field.

The piezoelectric properties of two-dimensional semiconductor nanobubbles present remarkable potential for application in flexible optoelectronic devices, and the piezoelectric field has emerged as an efficacious pathway for both the separation and migration of photogenerated electron-hole pairs, along with inhibition of recombination. However, the comprehension and control of photogenerated carrier dynamics within nanobubbles still remain inadequate. Hence, this study is dedicated to underscore the importance of in situ detection and detailed characterization of photogenerated electron-hole pairs in nanobubbles to enrich understanding and strategic manipulation in two-dimensional semiconductor materials. Utilizing frequency modulation kelvin probe force microscopy (FM-KPFM) and strain gradient distribution techniques, the existence of a piezoelectric field in monolayer WS2 nanobubbles was confirmed. Combining w/o and with illumination FM-KPFM, second-order capacitance gradient technique and in situ nanoscale tip-enhanced photoluminescence characterization techniques, the interrelationships among the piezoelectric effect, interlayer carrier transfer, and the funneling effect for photocarrier dynamics process across various nanobubble sizes were revealed. Notably, for a WS2/graphene bubble height of 15.45 nm, a 0 mV surface potential difference was recorded in the bubble region w/o and with illumination, indicating a mutual offset of piezoelectric effect, interlayer carrier transfer, and the funneling effect. This phenomenon is prevalent in transition metal dichalcogenides materials exhibiting inversion symmetry breaking. The implication of our study is profound for advancing the understanding of the dynamics of photogenerated electron-hole pair in nonuniform strain piezoelectric systems, and offers a reliable framework for the separation and modulation of photogenerated electron-hole pair in flexible optoelectronic devices and photocatalytic applications.

Enhanced Performance of Self-Powered Ga2O3/ZnO:V Heterojunction Solar-Blind Ultraviolet Photodetectors by Coupling Ferroelectricity and Piezoelectricity.

Ferroelectric materials have aroused increasing interest in the field of self-powered ultraviolet (UV) photodetectors (PDs) for their switchable spontaneous polarization. However, the utilization of ferroelectric materials to modulate the built-in electric field and energy band at the junction interface has rarely been investigated. Herein, we design and fabricate self-powered solar-blind UV PDs based on a Ga2O3/ZnO:V heterojunction. The performance of the Ga2O3/ZnO:V PD is significantly enhanced through the reasonable coupling of ferroelectricity and piezoelectricity within the ZnO:V film. The device at 260 nm exhibits excellent photoelectric properties with high peak responsivity of 64.5 mA/W, a specific detectivity of 3.8 × 1010 Jones, and a rise/decay time of 1.9/45.2 μs, together with reproducibility and stability. Systematical energy band diagram analysis reveals that the excellent performance of Ga2O3/ZnO:V PD can be attributed to the driving forces arising from the addition of the depolarization field and piezoelectric field, which increases the intensity of built-in electric field and promotes the separation and transport of photogenerated carriers at the heterojunction interface. The findings of our research provide a novel avenue and valuable guidance for the design of high-performance self-powered photodetectors.

Highly efficient Bi2Fe4O9-ZnIn2S4 Z-scheme heterojunction for piezo-photocatalytic overall water splitting under near-infrared light up to 1200 nm

Photocatalytic overall water splitting is considered as a sustainable and appealing strategy to solve the issues of energy supply and conversion. However, a critical hurdle to applying photocatalytic overall water splitting is the restricted light absorption and sluggish mobility of light-induced charge carriers in catalysts. Herein, a near-infrared light-responsive Bi2Fe4O9-ZnIn2S4 Z-scheme piezoelectric photocatalyst with a Fe-S bonded interface is constructed. This ingenious design synergistically utilizes the advantages of the Z-scheme, strong coupling interfaces, and piezoelectric field. The Bi2Fe4O9-ZnIn2S4 Z-scheme heterojunction significantly suppresses photogenerated carriers' recombine and extends photocatalytic response to the infrared light region, achieving highly efficient piezo-photocatalytic activity. Consequently, the optimized Bi2Fe4O9-ZnIn2S4 heterojunction displays an unprecedented piezo-photocatalytic H2 and O2 generation rate of 1862 and 927 μmol h−1 g−1 under sunlight illumination. This rate is approximately 4.9 and 10.0 times greater than that of photocatalysis and piezocatalysis alone. This study lays novel groundwork for developing future heterojunctions for photocatalytic water splitting.

Piezocatalysts and Piezo‐Photocatalysts: From Material Design to Diverse Applications

AbstractPiezocatalysis and piezo‐photocatalysis technology is a continuously developing catalytic technology based on the piezoelectric effect of catalysts, which breaks the barrier between mechanical and chemical energy. The piezoelectric polarization field formed by the mechanical deformation of piezoelectric materials is proven to effectively manipulate band structures, improve the separation of electron‐hole pairs and enhance the catalytic activity, thus alleviating energy crises and environmental issues. Herein, this review first introduces the technology of piezocatalysis and piezo‐photocatalysis, comprehensively summarizes the synthesis methods of piezo(photo)catalysis materials, and analyzes and discusses the measures to optimize the performance of piezo(photo)catalysts. The following systematically summarizes the characteristics and development of the current main piezo(photo)catalytic systems, and discusses the application of first principles calculations in piezo(photo)catalysis in combination with practical researches. Subsequently, the main application progress of piezo(photo)catalysis in environmental remediation, energy conversion, and biomedical therapy fields is presented. In the end, the current challenges, development direction, and future prospects are prospected.

Ab initio calculations of nonlinear susceptibility and multiphonon mixing processes in a 2DEG-piezoelectric heterostructure

Solid-state elastic-wave phonons are a promising platform for a wide range of quantum information applications including facilitating quantum transduction from microwave to optical electromagnetic fields, long-lived quantum memories, in addition to potentially acting as qubits themselves. An outstanding challenge and enabling capability in harnessing phonons for quantum information processing is achieving sufficiently strong nonlinear interactions between them. To this end, we propose a general architecture for generating strong quantum phononic nonlinearity using piezoelectric-semiconductor heterostructures consisting of a piezoelectric acoustic material hosting phononic modes that is in direct proximity to a two-dimensional electron gas (2DEG). Each phonon in the piezoelectric material carries an electric field, which extends into the 2DEG. The fields induce polarization of 2DEG electrons, which in turn interact with other piezoelectric phononic electric fields. The net result is coupling between the electric fields associated with the various phonon modes. We derive, from first principles, the nonlinear phononic susceptibility of a piezo-2DEG system and provide a prescription to calculate all orders of the susceptibility in a perturbative expansion. We show that many nonlinear processes are strongly favored at high electron mobility, motivating the use of the 2DEG to mediate the nonlinearities. We derive the first, second, and third-order susceptibilities and calculate them for the case of a lithium niobate surface acoustic wave interacting with a GaAs-AlGaAs heterostructure 2DEG. We show that, for this system, the strong third-order phononic nonlinearities generated could enable single-phonon Kerr shift in an acoustic cavity that exceeds realistic cavity linewidths, potentially leading to a new class of acoustic qubit. We further show that the strong second-order nonlinearity could be used to produce a high-gain, traveling-wave parametric amplifier to amplify—and ultimately detect—the outputs of the acoustic cavity qubits. Assuming favorable losses in such a system, the combination of these capabilities, combined with the ability to efficiently transduce phonons from microwave electromagnetic fields in transmission lines, thus hold promise for creating all-acoustic quantum information processors. Published by the American Physical Society 2024

Piezo-photocatalytic synergetic for H2O2 generation via dual-pathway over Z-scheme ZIF-L/g-C3N4 heterojunction

The constructed ZIF-L/g-C3N4 piezo-photocatalytic system showed exceptional H2O2 production yield. It was primarily attributable to the matched Z-scheme band alignments and the forceful piezoelectric field formed between g-C3N4 and ZIF-L, which was favor of reducing the energy barrier of electron excitation and directional transferring of photo-generated charge carriers. Meanwhile, the composition between ZIF-L and g-C3N4 can alter the H2O2 generation mechanism from single-pathway to dual-pathway. Thus, this mutual promotion significantly elevated the catalytic H2O2 production rate to 1.45 mmol g−1 h−1 without any contaminative scavenger. The catalytically produced H2O2 solution can be used to achieve ultrafast degradation of organic pollutants with 100% efficiency through homogeneous Fenton reaction within tens of seconds. The mediating multi-roles of natural organic matter (NOM) in regulating the H2O2 production were systematically investigated. Finite-element-method (FEM) simulations and density functional theory (DFT) calculations conjointly revealed the constructed piezo-photocatalytic system not only markedly accelerated separation of charge carriers, but also facilitated the activation of vital intermediates (O2*, OOH* and *OH) for H2O2 synthesis, which were the rate-determining steps for oxygen reduction reaction (ORR) and water oxidation reaction (WOR). This study will provoke the rational design of MOFs-based dual-pathway materials for piezo-photocatalytic H2O2 generation and follow-up applications.

Self-consuming expansion stress construct piezoelectric field to accelerate anion for SiO/PbZr0.52Ti0.48O3 with persistent lithium storage performance

The high theoretical specific capacity and suitable working potential of silicon oxides (SiOx) making it one of the most promising candidates for the next generation of lithium-ion battery anode materials. However, the large-scale application of SiOx in lithium-ion battery anodes is hampered by the huge volume change (>200 %) during cycling process. This experiment adopts a method which is completely contrary to the traditional modification method——composite with piezoelectric materials to take advantage of this expansion. During the lithiation process, the significant volume expansion stress of SiO is transformed into a driving force by PbZr0.52Ti0.48O3 (PZT) particles that enhances the transport of Li+. The polarization of PZT particles occurs as a result of the consumption of mechanical stress caused by the expansion of SiO, leading to the generation of a piezoelectric potential. Since then, the volume expansion stress of SiO when deintercalating lithium is converted into a potential difference, which can promote the migration of Li+. This process not only reduces the volume expansion of SiO, but also promotes the mobility of Li+. The SiO/PZT anode shows an admirable cycle performance: The discharge capacity is 825.4 mA h g−1, and the capacity retention ratio is reach up to 92.5 % (200 mA g−1, 200 cycles). These findings illuminate the surface coupling approach employed to regulate the behavior of interfacial Li+ kinetics, while simultaneously enhancing the structural stability of alloy-based anodes. This research will undoubtedly capture the attention of researchers engaged in the study of multifunctional interface design for electrochemical systems.

Piezo-enhanced photocatalysis of MoS2/Bi4O5Br2/PVDF-HFP film for wastewater purification

To date, the piezoelectric field has been demonstrated as a promising approach to inhibit the recombination of photogenerated carrier in photocatalyst applications. Herein we propose a MoS2/Bi4O5Br2/PVDF-HFP piezo-photocatalytic film in the organic pollutants remediation. MoS2/Bi4O5Br2 as the photocatalytic material is incorporated to poly (vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP) as the supporting layer via a simple phase transition method. The polarised electric field generated on PVDF-HFP and MoS2/Bi4O5Br2 under aeration synergised with the built-in electric field formed between MoS2/Bi4O5Br2 Z-scheme heterojunction to promote the interfacial charge transfer. The degradation rates of rhodamine B (RhB) and tetracycline hydrochloride (TC) under aeration and visible light irradiation in 60 min reached 98.9% and 92.2%, respectively. Meanwhile, density functional theory calculations (DFT) further demonstrated the effective charge separation and transfer induced by the Z-scheme charge transfer mechanism constructed by MoS2 composite with Bi4O5Br2, as well as the synergistic effect of the double electric field in favour of suppressing carrier recombination. This work provides an interesting solution for effectively combining piezoelectric catalysis with photocatalysis.

Ultrasound-Triggered Piezoelectric Catalysis of Zinc Oxide@Glucose Derived Carbon Spheres for the Treatment of MRSA Infected Osteomyelitis.

Currently, methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis is a clinically life-threatening disease, however, long-term antibiotic treatment can lead to bacterial resistance, posing a huge challenge to treatment and public health. In this study, glucose-derived carbon spheres loaded with zinc oxide (ZnO@HTCS) are successfully constructed. This composite demonstrates the robust ability to generate reactive oxygen species (ROS) under ultrasound (US) irradiation, eradicating 99.788% ± 0.087% of MRSA within 15min and effectively treating MRSA-induced osteomyelitis infection. Piezoelectric force microscopy tests and finite element method simulations reveal that the ZnO@HTCS composite exhibits superior piezoelectric catalytic performance compared to pure ZnO, making it a unique piezoelectric sonosensitizer. Density functional theory calculations reveal that the formation of a Mott-Schottky heterojunction and an internal piezoelectric field within the interface accelerates the electron transfer and the separation of electron-hole pairs. Concurrently, surface vacancies of the composite enable the adsorption of a greater amount of oxygen, enhancing the piezoelectric catalytic effect and generating a substantial quantity of ROS. This work not only presents a promising approach for augmenting piezoelectric catalysis through construction of a Schottky heterojunction interface but also provides a novel, efficient therapeutic strategy for treating osteomyelitis.

A self-standing dual-electric field synergistic Janus nanofibre piezoelectric photocatalyst with degradation of antibiotics: Performances, DFT calculation and mechanism unveiling

A self-standing dual-electric field synergistic [TiO2/polyvinylidene fluoride (PVDF)]//[g-C3N4 tube/PVDF] Janus nanofibres (named as [TP]//[CTP]JNs) S-scheme heterostructure piezoelectric photocatalyst is designed and constructed via conjugative electrospinning. Dual-fields of built-in electric fields supplied by S-scheme heterostructure and piezoelectric field formed by PVDF jointly boost separation and transfer of photo-induced charges. As a case study, piezoelectric photocatalytic efficiency of [TP]//[CTP]JNs for tetracycline hydrochloride (TCH) under ultrasonic united with simulated sunlight illumination is 93.35% (40 min), which is 1.39 times of the photocatalytic efficiency (light illumination only) and 5.32 times of piezoelectric catalytic efficiency (applying ultrasonic only), proving the advantages of the synergistic effect of piezoelectric catalysis and photocatalysis on contaminant degradation. The dynamic behaviors of photocatalysis and photo-generated charges are deeply revealed through fs-TA and TRPL decay spectra, and the degradation pathways of antibiotics are reasonably speculated by combining LCMS spectra with Fukui index. By the degradation ability, COMSOL simulation and DFT calculation, the structural advantage of Janus nanofibers is fully verified, and S-scheme charge transfer mechanism is confirmed by combining a series of sound ample experiments with theoretical calculations. Additionally, the construction mechanism of Janus nanofibers is proposed, and corresponding construction technique is established.

Piezoelectric field-modulated peroxymonosulfate nonradical oxidation of bisphenol A via Bio-MOF-1: The dominant contribution of singlet oxygen

Bisphenol A (BPA) has raised worldwide concern owing to its ecological risks, highlighting the urgent need to develop efficient removal strategies in wastewater treatment. Ametal–organic framework (Bio-MOF-1) piezoelectrically activating peroxymonosulfate (PMS) process (Bio-MOF-1/PMS/US) was developed to remove BPA at 98.5%, which was 3.5 times higher than the Bio-MOF-1/US process. Further analysis confirmed that the piezoelectric field initiated by Bio-MOF-1 could reduce the activation energy of PMS and then promote the reaction of PMS with holes and electrons to convert into 1O2 and OH. The steady-state concentration of 1O2 was 4 orders of magnitude higher than OH, indicating the dominant contribution of 1O2 for BPA removal, which resulted in the efficient BPA removal from a variety of anions, organics, and municipal wastewater through a low-risk manner. This work provides new perspectives for the application of MOF-based materials in the field of piezoelectric catalysis and promising applications in wastewater remediation.

Piezoelectric Polarization and Sulfur Vacancy Enhanced Photocatalytic Hydrogen Evolution Performance of Bi2S3/ZnSn(OH)6 Piezo-photocatalyst.

The combination of piezoelectric catalysis and photocatalysis could effectively enhance the carrier separation efficiency and further improve the hydrogen production activity. However, piezoelectric polarization always suffers from a low polarization strength, which severely restricts its actual applications. In this study, we successfully synthesized a novel sulfur vacancy-rich Bi2S3/ZnSn (OH)6 (BS-12/ZSH) piezo-photocatalyst for hydrogen evolution through water splitting. Notably, the piezo-photocatalytic hydrogen generation rate of the 8% BS-12/ZSH catalyst (336.21 μmol/g/h) was superior to that of pristine ZSH (29.71 μmol/g/h) and BS-12 (21.66 μmol/g/h). In addition, the hydrogen generation for 8% BS-12/ZSH (336.21 μmol/g/h) under ultrasonic coupling illumination was significantly higher than that under single illumination (52.09 μmol/g/h) and ultrasound (121.90 μmol/g/h), owing to the cooperative interaction of the sulfur vacancy and piezoelectric field. Various characterization analyses confirmed that (1) the introduction of sulfur vacancies in BS-12 provided more active sites, (2) BS-12 with sulfur vacancies acted as a co-catalyst to accelerate the hydrogen production rate, and (3) the piezoelectric field eliminated the electrostatic shielding and offered an additional driving force, which effectively promoted the separation of electron-hole pairs. This research clearly reveals the synergistic effect between piezocatalysis and photocatalysis as well as offers a promising sight for the rational design of high-efficiency piezo-photocatalysts.