Atomically thin Bi/Bi4Ti3O12 heterojunction mediated increasing active photogenerated carriers for boosting photocatalytic activity

Construction of novel Ag/AgI/Bi4Ti3O12 plasmonic heterojunction: A study focusing on the performance and mechanism of photocatalytic removal of tetracycline

As a result of the insufficient absorption of visible light, the application of Bi4Ti3O12 in the field of photocatalysis is limited. Ag/AgI was uniformly modified on the surface of the nanoflower bulb of Bi4Ti3O12 by simple precipitation method and photodeposition. The fabricated Ag/AgI/Bi4Ti3O12 obtained an ultra-high tetracycline (TC) removal rate under visible light irradiation. And the synergetic effects caused by the surface plasmon resonance (SPR) effect of Ag, the photosensitivity of AgI and the p-n heterojunction are the key to improving the photocatalytic performance of materials. Besides, four plausible photodegradation pathways of TC were proposed and its intermediates were evaluated for toxicity, showing a significant decrease in toxicity after photoreaction.

Study of bismuth metal organic skeleton composites with photocatalytic antibacterial activity

A composite based on Ag and carbon quantum dot (CQDs) doped bismuth metal organic framework (CAU-17) was synthesized by a one-step thermal solvent in situ growth. The microstructure, chemical composition, morphology, photogenerated electron-hole pairs, and photocatalytic activity of the composite were characterized. The produced composite with its unique energy band structure, enhances the visible light absorption and effectively delays the recombination of the photogenerated carriers. On the other hand, the modification with CQDs increases the concentration and transport rate of photogenerated carriers mainly attributed to their superior electron transport capacity and light trapping ability. The photocatalytic antibacterial effect of CAU-17/Ag/CQDs against common Gram-positive, Gram-negative bacteria (Staphylococcus aureus, Escherichia coli) and drug-resistant bacteria (methicillin-resistant Staphylococcus aureus), as well as its inhibition against HepG2 tumor cell were investigated. The results showed that CAU-17/Ag/CQDs exhibited a photocatalytic antibacterial effect with an inactivation rate as high as 99.9 %. At the low dose (0.2 mg/mL), CAU-17/Ag/CQDs indicated a significant inhibition against bacterial growth 20 min after visible light exposure, whereas at the concentration of 0.5 mg/mL, CAU-17/Ag/CQDs completely killed all the tested bacteria. At the concentration of 0.8 mg/mL, the inhibition rate against HepG2 tumor cells reached 75 %. The excellent photocatalytic property of the as prepared composite contributed to the doping of Ag and CQDs, which fundamentally altered the morphology and energy band distribution. Such a composite can be developed into an effective photocatalytic disinfection system and applied to water purification systems, biofilm rejection, combating different antibiotic resistances, and tumor therapy.

Research progress of photocatalysis for algae killing and inhibition: a review

The healthy development of biodiversity has been threatened frequent water eutrophication. In recent years, photocatalytic technology, which has attracted researchers' attention, not only showed increasing potential in the field of organic pollutant degradation, but also many kinds of photocatalysts were used in the field of red tide pollution control at present, which showed superior ability to inactivate harmful algae and degrade algal toxins. Researches have also explored the mechanisms of photocatalytic algae inhibition. In this study, the current research progress in the field of photocatalytic algae inhibition was systematically discussed from several aspects, such as common types of photocatalysts, modification methods of photocatalysts, types of tested algae for photocatalytic algae inhibition, and action mechanism of inactivated algae cells, so as to provide a certain theoretical basis for further application research of photocatalysts in the field of algae removal in the later period.

Accelerating the Fe(III)/Fe(II) cycle via enhanced electronic effect in NH2-MIL-88B(Fe)/TPB-DMTP-COF composite for boosting photo-Fenton degradation of sulfamerazine

In the photo-Fenton reactions, fast recombination of photoinduced electrons and holes in Fe-based metal-organic frameworks (Fe-MOFs) slows Fe(III)/Fe(II) cycle, which remains big challenge that significantly retards the overall process. Herein, NH₂-MIL-88B(Fe) (NM88) was modified with 3,5-diaminobenzoic acid (DB) and TPB-DMTP-COF (COF-OMe) to in situ construct NM88(DB)_0.85/COF-OMe composite that could strongly harvest the visible light for photo-Fenton degradation of sulfamerazine (SMR). With the addition of DB, electron-donating effect of NM88 was strengthened, which then promoted amino groups to react with aldehyde groups (Schiff-base), and thus highly facilitated the interfacial contact between NM88 and COF-OMe. Such modifications increased the degradation rate constants for NM88(DB)_0.85/COF-OMe to 15.1 and 17.3 times that of NM88 and COF-OMe respectively with good reusability. Moreover, the catalyst exhibited 32-170 times higher degradation kinetics in comparison to other reported catalysts. Results showed that due to the Schiff-base reaction between NM88(DB) and COF-OMe, electron density on Fe(III) was decreased; and the photogenerated electrons of COF-OMe moved to NM88(DB) to reduce Fe(III), thus resulting in the generation of highly active Fe(II) and ·OH species. Furthermore, the main reactive species were determined to be ·OH and ·O₂^- by trapping experiments, and a possible mechanism of the degradation system followed Z-scheme charge transfer.

Improved photoredox activity of the 2D Bi4Ti3O12–BiVO4–Bi4V2O10 heterostructure via the piezoelectricity-enhanced charge transfer effect

The formation of the 2D Bi4Ti3O12–BiVO4–Bi4V2O10 heterostructure and the piezoelectric effect on photoredox activity improvements.