Unmasking the Role of an Amorphous/Amorphous Interface and a Crystalline/Amorphous Interface in the Transition of Charge Carriers on the CN/SiO2/WO3 Photocatalyst

Tourmaline/pyrite dual mineral photocatalysis with a powerful surface electric field for efficient antibiotic removal

Pyrite (FeS2) has garnered attention due to its narrow bandgap, high light absorption, and low cost. However, the rapid recombination of charge carriers hinders its practical application. Surface electric field is a unique characteristic of tourmaline, which can induce effective separation of photo generated electrons and holes. This study successfully combined two directly mined natural minerals, tourmaline and pyrite, to form TFS. Characterization and experiments show that the surface electric field of tourmaline can significantly enhance the photocatalytic activity of TFS. Tetracycline (TC, 50 ppm) was degraded by 95% with 60 min, and the TFS reaction rate constant reached 0.0439 min-1, which is 6.1 times and 17.3 times higher than that of tourmaline and FeS2. Additionally, it significantly improved light absorption and charge carrier separation capabilities. After simulating various natural environmental factors, TFS demonstrated practicality. Considered analysis of active substances and detection revealed that h+ and 1O2 radicals are significant contributors, and the photocatalytic mechanism was proposed. Furthermore, the transformation pathways and toxicity of metabolites were studied. This research offers further inspiration and insights for improving photocatalytic material performance and the green governance environment of natural resources.

Narrow Bandgap Schottky Heterojunction Sonosensitizer with High Electron-Hole Separation Boosted Sonodynamic Therapy in Bladder Cancer

Sonodynamic therapy (SDT) is applied to bladder cancer (BC) given its advantages of high depth of tissue penetration and nontoxicity due to the unique anatomical location of the bladder near the abdominal surface. However, low electron-hole separation efficiency and wide bandgap of sonosensitizers limit the effectiveness of SDT. This study aims to develop a TiO2-Ru-PEG Schottky heterojunction sonosensitizer with high electron-hole separation and narrow bandgap for SDT in BC. Density functional theory (DFT) calculations and experiments collectively demonstrate that the bandgap of TiO2-Ru-PEG is reduced due to the Schottky heterojunction with the characteristic of crystalline-amorphous interface formed by the deposition of ruthenium (Ru) within the shell layer of TiO2. Thanks to the enhancement of oxygen adsorption and the efficient separation of electron-hole pairs, TiO2-Ru-PEG promotes the generation of reactive oxygen species (ROS) under ultrasound (US) irradiation, resulting in cell cycle arrest and apoptosis of bladder tumor cells. The in vivo results prove that TiO2-Ru-PEG boosted the subcutaneous and orthotopic bladder tumor models while exhibiting good safety. This study adopts the ruthenium complex for optimizing sonosensitizers, contributing to the progress of SDT improvement strategies and presenting a paradigm for BC therapy.

In-situ grown carbon as charge transfer medium for enhanced photoinduced electrons extraction from polymer carbon nitride toward TiO2

Interfacial charge transfer resistance is one of the main limiting factors for realizing high photocatalytic efficiency of heterostructures system. Herein, an activated carbon layer is successfully introduced between the interface of polymer carbon nitride (CN) and TiO2 heterostructure (CNP-x) as charge transfer medium by in situ pyrolysis carbonization method. Because of the lower spatial resistance of the crystalline/amorphous interface and the fast carrier transportation character of activated carbon, the efficiency of TiO2 in extracting photoinduced electrons from CN was significantly improved. That is, the separation/transport of photocarriers in CNP-x heterostructure is accelerated, and the recombination time of photogenerated electrons and holes is prolonged. The CNP-1 exhibits a H2 evolution rate of 1298.5 μmol h-1 with apparent quantum yield (AQY) of 34.5 %, 20.3 % and 12.6 % at 365 nm, 380 nm and 400 nm, respectively. This work offers a novel and unique strategy to promote interface charge separation and transport of CN-based heterostructures by accurately introduction charge transfer medium.

Internal electric fields drive dual S-scheme heterojunctions: Insights into the role of the triple interlaced lattice

The internal electric field induced by the lattice interfaces in a heterojunction can facilitate charge transfer, thereby improving the photocatalytic performance. However, the details of the relationship between the lattice interfaces and the charge transfer mechanism in heterojunctions remain unclear. In this study, a Bi2WO6/Bi2O2CO3/C3N4 heterojunction (BBC) with an interlaced lattice was prepared, and the role of the interlaced lattice in charge transfer was revealed. Compared to pristine Bi2O2CO3, Bi2WO6, and C3N4, BBC exhibited an increased ciprofloxacin degradation rate constant (0.0573 min-1). A series of experiments were performed to reveal the role of the interlaced lattice interface in the enhanced photocatalytic performance. The results show that the driving force provided by the interlaced lattice interface changes the charge transfer mechanism from a dual Ⅱ-scheme to a dual S-scheme. This work provides profound insights into the effects of lattice interfaces in heterojunctions and the design of efficient photocatalysts.

Advanced Functional Carbon Nitride by Implanting Semi-Isolated VO2 Active Sites for Photocatalytic H2 Production and Organic Pollutant Degradation

It is critical to facilitate surface interaction for liquid-solid two-phase photocatalytic reactions. This study demonstrates more advanced, efficient, and rich molecular-level active sites to extend the performance of carbon nitride (CN). To achieve this, semi-isolated vanadium dioxide is obtained by controlling the growth of non-crystalline VO₂ anchored into sixfold cavities of the CN lattice. As a proof-of-concept, the experimental and computational results solidly corroborate that this atomic-level design has potentially taken full advantage of two worlds. The photocatalyst comprises the highest dispersion of catalytic sites with the lowest aggregation, like single-atom catalysts. It also demonstrates accelerated charge transfer with the boosted electron-hole pairs, mimicking heterojunction photocatalysts. Density functional theory calculations show that single-site VO₂ anchored into the sixfold cavities significantly elevates the Fermi level, compared with the typical heterojunction. The unique features of semi-isolated sites result in a high visible-light photocatalytic H₂ production of 645 µmol h^-1 g^-1 with only 1 wt% Pt. They also represent an excellent photocatalytic degradation for rhodamine B as well as tetracycline, surpassing the activities obtained from many conventional heterojunctions. This study presents exciting opportunities for the design of new heterogeneous metal oxide for a variety of reactions.

Mapping short-range order at the nanoscale in metal-organic framework and inorganic glass composites

Characterization of nanoscale changes in the atomic structure of amorphous materials is a profound challenge. Established X-ray and neutron total scattering methods typically provide sufficient signal quality only over macroscopic volumes. Pair distribution function analysis using electron scattering (ePDF) in the scanning transmission electron microscope (STEM) has emerged as a method of probing nanovolumes of these materials, but inorganic glasses as well as metal-organic frameworks (MOFs) and many other materials containing organic components are characteristically prone to irreversible changes after limited electron beam exposures. This beam sensitivity requires 'low-dose' data acquisition to probe inorganic glasses, amorphous and glassy MOFs, and MOF composites. Here, we use STEM-ePDF applied at low electron fluences (10 e^- Å^-2) combined with unsupervised machine learning methods to map changes in the short-range order with ca. 5 nm spatial resolution in a composite material consisting of a zeolitic imidazolate framework glass a_gZIF-62 and a 0.67([Na₂O]_0.9[P₂O₅])-0.33([AlO_3/2][AlF₃]_1.5) inorganic glass. STEM-ePDF enables separation of MOF and inorganic glass domains from atomic structure differences alone, showing abrupt changes in atomic structure at interfaces with interatomic correlation distances seen in X-ray PDF preserved at the nanoscale. These findings underline that the average bulk amorphous structure is retained at the nanoscale in the growing family of MOF glasses and composites, a previously untested assumption in PDF analyses crucial for future non-crystalline nanostructure engineering.

Fabrication of an amorphous metal oxide/p-BiVO4 photocathode: understanding the role of entropy for reducing nitrate to ammonia

Entropy regulation makes an amorphous metal oxide/p-BiVO4 heterostructure a desirable catalyst for the NO3− reduction reaction in a photoelectrochemical system.