Promoting Piezocatalytic H O Production in Pure Water by Loading Metal-Organic Cage-Modified Gold Nanoparticles on Graphitic Carbon Nitride.

Piezocatalytic hydrogen peroxide (H O ) production is a green synthesis method, but the rapid complexation of charge carriers in piezocatalysts and the difficulty of adsorbing substrates limit its performance. Here, metal-organic cage-coated gold nanoparticles are anchored on graphitic carbon nitride (MOC-AuNP/g-C N ) via hydrogen bond to serve as the multifunctional sites for efficient H O production. Experiments and theoretical calculations prove that MOC-AuNP/g-C N simultaneously optimize three key parts of piezocatalytic H O production: i) the MOC component enhances substrate (O ) and product (H O ) adsorption via host-guest interaction and hinders the rapid decomposition of H O on MOC-AuNP/g-C N , ii) the AuNP component affords a strong interfacial electric field that significantly promotes the migration of electrons from g-C N for O reduction reaction (ORR), iii) holes are used for H O oxidation reaction (WOR) to produce O and H to further promote ORR.

Water flow promoted charge separation in piezoelectric BiTiO for the enhanced photocatalytic degradation of antibiotic.

Addressing the issue of antibiotic residues in the environment is key to improving the quality of aquatic environments and reducing human health risks. In this study, piezoelectric bismuth titanate (BiTiO) nanosheets are synthesized and employed to conduct antibiotic degradation. The piezoelectric potential induced by the water flow shear force is utilized to facilitate charge separation and migration in the photocatalytic process and enhance the catalytic degradation of antibiotic wastewater.

Efficient piezo-photocatalysis of 0D/2D α-FeO/BiWO: Synergy of weak force-driven piezoelectric polarization and Z-scheme junction.

Photocatalysis shows huge potential in environmental purification, but suffers from fast photocharge recombination and finite photoabsorption. Piezoelectric polarization is perceived as a promising approach to drive charge separation, but it always relies on the energy-guzzling ultrasonic vibration. Herein, a piezo-photocatalytic system integrating dual electric fields constructed by weak force-driven piezoelectric polarization and Z-scheme junction is developed in 0D/2D α-FeO/BiWO.

Mineral phase transition characteristics and its effects on the stabilization of heavy metals in industrial hazardous wastes incineration (IHWI) fly ash via microwave-assisted hydrothermal treatment.

Toxic heavy metals in industrial hazardous waste incineration (IHWI) fly ash can be effectively stabilized by using microwave-assisted hydrothermal technology. However, few works have focused on the relationship between mineralogical conversion and stability of heavy metals of fly ash during hydrothermal process. This study investigated the effect of mineral phase transition process on the stabilization and migration behavior of heavy metals in IHWI fly ash using coal fly ash as silicon‑aluminum additive.

Photocatalysis Enhanced by External Fields.

The efficient conversion of solar energy by means of photocatalysis shows huge potential to relieve the ongoing energy crisis and increasing environmental pollution. However, unsatisfactory conversion efficiency still hinders its practical application. The introduction of external fields can remarkably enhance the photocatalytic performance of semiconductors from the inside out.

Ferroelectric spontaneous polarization steering charge carriers migration for promoting photocatalysis and molecular oxygen activation.

Introducing a polarization electric field in photocatalyst system is regarded asa new concept for photocatalytic activity enhancement. In this work, we first unearth that the spontaneous polarization of ferroelectric BaTiO promotes the photocatalytic and molecular oxygen activation performance of the narrow-band-gap semiconductor BiOI. Ferroelectric tetragonal-phase BaTiO (T-BaTiO) were prepared via calcination of nonferroelectric cubic-phase BaTiO (C-BaTiO), and their polarization ability was verified via ultrasonication-assisted piezoelectric catalytic degradation.

Macroscopic Polarization Enhancement Promoting Photo- and Piezoelectric-Induced Charge Separation and Molecular Oxygen Activation.

Efficient photo- and piezoelectric-induced molecular oxygen activation are both achieved by macroscopic polarization enhancement on a noncentrosymmetric piezoelectric semiconductor BiOIO . The replacement of V ions for I in IO polyhedra gives rise to strengthened macroscopic polarization of BiOIO , which facilitates the charge separation in the photocatalytic and piezoelectric catalytic process, and renders largely promoted photo- and piezoelectric induced reactive oxygen species (ROS) evolution, such as superoxide radicals ( O ) and hydroxyl radicals ( OH). This work advances piezoelectricity as a new route to efficient ROS generation, and also discloses macroscopic polarization engineering on improvement of multi-responsive catalysis.