Wet-chemical intercalation of Bi4TaO8Br with self-adaptive structural deformation for enhanced photocatalytic performance

A small specific surface area and severe charge carrier recombination greatly limit the photocatalytic efficiency of semiconductors. Herein, we developed a novel wet-chemical intercalation strategy by using the NaBH4 reagent for in situ intercalation-assisted expansion and surface/interface reconstruction of Bi4TaO8Br, which exhibits an enhanced specific surface area and charge carrier separation features. This work highlights intercalation of semiconductors for achieving enhanced photocatalytic performance and provides a new idea to synergistically regulate the morphology and surface/interface composition of semiconductors.

Hydrothermal Synthesis of β-Nb2ZnO6 Nanoparticles for Photocatalytic Degradation of Methyl Orange and Cytotoxicity Study

β-Nb₂ZnO₆ nanoparticles were synthesized by a hydrothermal process and calcined at two temperatures, 500 °C and 700 °C, and assigned as A and B, respectively. X-ray diffraction, together with transmission electron microscopy, revealed that the β-Nb₂ZnO₆ nanoparticles calcined at 700 °C (B) were more crystalline than the β-Nb₂ZnO₆ calcined at 500 °C (A) with both types of nanoparticles having an average size of approximately 100 nm. The physiochemical, photocatalytic, and cytotoxic activities of both types of β-Nb₂ZnO₆ nanoparticles (A and B) were examined. Interestingly, the photodegradation of methyl orange, used as a standard for environmental pollutants, was faster in the presence of the β-Nb₂ZnO₆ nanoparticles calcined at 500 °C (A) than in the presence of those calcined at 700 °C (B). Moreover, the cytotoxicity was evaluated against different types of cancer cells and the results indicated that both types of β-Nb₂ZnO₆ nanoparticles (A and B) exhibited high cytotoxicity against MCF-7 and HCT116 cells but low cytotoxicity against HeLa cells after 24 and 48 h of treatment. Overall, both products expressed similar EC₅₀ values on tested cell lines and high cytotoxicity after 72 h of treatment. As a photocatalyst, β-Nb₂ZnO₆ nanoparticles (A) could be utilized in different applications including the purification of the environment and water from specific pollutants. Further biological studies are required to determine the other potential impacts of utilizing β-Nb₂ZnO₆ nanoparticles in the biomedical application field.

Facet-dependent CdS/Bi4TaO8Cl Z-scheme heterojunction for enhanced photocatalytic tetracycline hydrochloride degradation and the carrier separation mechanism study via single-particle spectroscopy

An efficient lateral Z-scheme CdS/Bi4TaO8Cl photocatalyst based on the facet-dependent charge separation mechanism and the bandgap structure characteristic was designed.

Sonochemical synthesis of ZnCo2O4/Ag3PO4 heterojunction photocatalysts for the degradation of organic pollutants and pathogens: a combined experimental and computational study

ZnCo2O4/Ag3PO4 heterostructure nanoparticles were prepared by a facile ultrasonic method and characterized by various techniques. The photocatalytic activity of ZnCo2O4/Ag3PO4 nanoparticles was investigated for the degradation of organic pollutants (methyl...

Flower-like Fe7S8/Bi2S3 superstructures with improved near-infrared absorption for efficient chemo-photothermal therapy

Although various photothermal therapy (PTT) nanoagents have been developed in recent years, the rational design and easy synthesis of a PTT nanoplatform with improved near-infrared (NIR) absorption have remained challenging. Herein, via a facile one-pot solvothermal strategy, hydrophilic nanosheet-assembled flower-like Fe7S8/Bi2S3 superstructures were fabricated successfully. Such nanoflowers exhibit improved NIR absorption, which is 1.54 times higher than that of pure Bi2S3 nanosheets at a wavelength of 808 nm. Attractively, these nanoflowers could serve as a drug delivery carrier with controlled release under pH/NIR stimuli and display a fascinating chemo-photothermal synergetic therapeutic effect both in vitro and vivo. The resulting nanoflowers may open up a way for the design of other nanoagents with an improved NIR absorption and chemo-photothermal cancer therapy effect.

Exploration of catalytic and cytotoxicity activities of CaxMgxNi1-2xFe2O4 nanoparticles

The Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) nanoparticles (NPs) have been synthesized hydrothermally. The XRD analyses confirmed the purity of all products and their spherical morphology and compositions were explained by SEM, TEM, EDX and Elemental mapping analyses. Results confirmed the composition of Ca_xMg_xNi_1-2xFe₂O₄. The surface area of them was determined by BET analysis. Results indicated that when x is increased surface area of Ca_xMg_xNi_1-2xFe₂O₄ is decreased as compare with x = 0.0, however, at high composition (x = 0.05), surface area is increased. Catalytic activity of Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) NPs was studied for the reduction of 4-nitrophenol as a model compound. Reaction was monitored by UV-spectrophotometer at room temperature and at different times. Among different compositions of Ca_xMg_xNi_1-2xFe₂O₄, it was noticed that x = 0.04 exhibited more activity for the reduction of 4-nitrophenol and x = 0.03 was observed least active. Results suggested that Ca_xMg_xNi_1-2xFe₂O₄ could be useful material for catalytic applications. Cytotoxicity activity of Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) NPs against HCT116 (Human colon cancer cell line) cell line and MCF-7 (breast cancer cell line) was evaluated by using MTT assay. It was observed that Ca_xMg_xNi_1-2xFe₂O₄ (x ≤ 0.05) NPs exhibited less cytotoxicity. Due to less cytotoxicity, Ca_xMg_xNi_1-2xFe₂O₄ may also be useful in the field of biomedical applications.

Preparation, formation mechanism, photocatalytic, cytotoxicity and antioxidant activity of sodium niobate nanocubes

A hydrothermal method was employed to prepare the sodium niobate (NaNbO₃) nanocubes. We executed time dependent experiments to illustrate the formation mechanism of sodium niobate nanocubes. It was observed that the morphology of NaNbO₃ nanocubes was dependent on the reaction time and 12hr reaction time was found to be suitable. Morphology, composition, structure and optical properties of sodium niobate nanocubes were evaluated by scanning electron microscope, X-ray energy-dispersive spectrometer, X-ray diffraction and UV-visible diffuse reflectance spectrometer. The photocatalytic activity of sodium niobate was studied for photocatalytic hydrogen production. It was anticipated that the sodium niobate (NaNbO₃) cubes exhibited good photocatalytic activity under UV light irradiation using lactic acid as sacrificial agent. The cytotoxicity activity of sodium niobate nanocubes was studied as well at different concentrations (5 mg/mL, 3 mg/mL, 1 mg/mL, and 0.25 mg/mL) against human colon colorectal carcinoma cell line (HCT116) by MTT assay and EC₅₀ was found to be 1.9 mg/mL. Sodium niobate proved to be a good DPPH free radical scavenging material, tested at different concentrations. It was noticed that peak intensity at 517 nm was decreased after 30 minute incubation, further supporting the antioxidant activity. This study will be useful for design and engineering of materials that can be used in biomedical applications and in photocatalysis.

Flux synthesis of regular Bi4TaO8Cl square nanoplates exhibiting dominant exposure surfaces of {001} crystal facets for photocatalytic reduction of CO2 to methane

Herein, orthorhombic regular Bi₄TaO₈Cl square nanoplates with an edge length of about 500 nm and a thickness of about 100 nm were successfully synthesized using a facile molten salt route. The as-prepared square nanoplates have been proven to be of {001} crystal facets as two dominantly exposed surfaces. The density functional theory calculation and photo-deposition of noble metal experiment demonstrate the electron and hole separation on different crystal facets and reveal that {001} crystal facets are in favor of the reduction reaction. Since the square nanoplate structure exhibits dominant exposure surfaces of the {001} facets, the molten salt route-based samples basically possess an obviously higher photocatalytic activity than those prepared by the solid state reaction (SSR) method. This study may provide inspiration for fabricating efficient photocatalysts.

Controllable synthesis of perovskite-like PbBiO2Cl hollow microspheres with enhanced photocatalytic activity for antibiotic removal

Novel perovskite-like PbBiO₂Cl materials with hollow and porous sphere-like structures were successfully synthesized using a polyvinyl pyrrolidone (PVP) and 1-hexadecyl-3-methylimidazolium chlorine ([C₁₆mim]Cl) complex system.