Bandgap-engineered ferroelectric single-crystalline NBT-BT based nanocomposites with excellent visible light-ultrasound catalytic performance

Advancing piezoelectric 2D nanomaterials for applications in drug delivery systems and therapeutic approaches

Precision drug delivery and multimodal synergistic therapy are crucial in treating diverse ailments, such as cancer, tissue damage, and degenerative diseases. Electrodes that emit electric pulses have proven effective in enhancing molecule release and permeability in drug delivery systems. Moreover, the physiological electrical microenvironment plays a vital role in regulating biological functions and triggering action potentials in neural and muscular tissues. Due to their unique noncentrosymmetric structures, many 2D materials exhibit outstanding piezoelectric performance, generating positive and negative charges under mechanical forces. This ability facilitates precise drug targeting and ensures high stimulus responsiveness, thereby controlling cellular destinies. Additionally, the abundant active sites within piezoelectric 2D materials facilitate efficient catalysis through piezochemical coupling, offering multimodal synergistic therapeutic strategies. However, the full potential of piezoelectric 2D nanomaterials in drug delivery system design remains underexplored due to research gaps. In this context, the current applications of piezoelectric 2D materials in disease management are summarized in this review, and the development of drug delivery systems influenced by these materials is forecast.

Signally enhanced piezo-photocatalysis of Bi0.5Na0.5TiO3/MWCNTs composite for degradation of rhodamine B

Recently, the lead-free piezoelectric material Bi_0.5Na_0.5TiO₃ (BNT) has been adopted for piezo-catalysis and synergistic catalysis, such as piezo-photocatalysis. Nonetheless, the catalytic effect of single BNT is too weak to degrade multifarious contaminants. Here, BNT and multi-walled carbon nanotubes (MWCNTs) composite were prepared and the catalytic performance of BNT was prominently boosted by introducing MWCNTs as the electron capturer. Particularly, the degradation rate of Rhodamine B (RhB, a typical contaminant) could reach 90% within 30 min, with a high rate constant of 0.0805 min^-1. The specific degradation pathway of RhB was analyzed. The formation of oxygen vacancies was confirmed by XPS analysis, and the vital role of oxygen vacancies in the separation of photo-generated carriers was elucidated. Meanwhile, the BNT/MWCNTs composites manifested stronger transient current response compared to single BNT under the action of light irradiation and ultrasonic vibration, respectively. According to impedance analysis, the composites exhibited lower carrier transport resistance. Eventually, the mechanism of enhanced piezo-photocatalysis was explained in detail. This study provides an effective route to break the shackle of carrier recombination and speed up the carrier transport in piezo-photocatalytic materials.

Bi4TaO8Cl as a New Class of Layered Perovskite Oxyhalide Materials for Piezopotential Driven Efficient Seawater Splitting

Piezocatalytic water splitting is an emerging approach to generate "green hydrogen" that can address several drawbacks of photocatalytic and electrocatalytic approaches. However, existing piezocatalysts are few and with minimal structural flexibility for engineering properties. Moreover, the scope of utilizing unprocessed water is yet unknown and may widely differ from competing techniques due to the constantly varying nature of surface potential. Herein, we present Bi₄TaO₈Cl as a representative of a class of layered perovskite oxyhalide piezocatalysts with high hydrogen production efficiency and exciting tailorable features including the layer number, multiple cation-anion combination options, etc. In the absence of any cocatalyst and scavenger, an ultrahigh production rate is achievable (1.5 mmol g^-1 h^-1), along with simultaneous generation of value-added H₂O₂. The production rate using seawater is somewhat less yet appreciably superior to photocatalytic H₂ production by most oxides as well as piezocatalysts and has been illustrated using a double-layer model for further development.