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Photothermal therapy (PTT) agents possess the capability to absorb light and transform it into heat, providing a promising approach for inhibiting and eradicating tumor cells. Therefore, there is a significant interest in developing novel PTT agents with superior biocompatibility and photothermal conversion efficiency. Herein, Ag2S/g-C3N4 nanoparticles (NPs) with exceptional near-infrared absorption performance were successfully synthesized using a hydrothermal method. The photothermal conversion efficiency of Ag2S/g-C3N4 NPs reached 31.28% under 808 nm laser irradiation, surpassing that of most reported PTT agents. The simultaneous application of an 808 nm laser resulted in a significant augmentation of reactive oxygen species (ROS) generation, including ·O2– and ·OH, which, in turn, triggered apoptosis and the death of tumor cells via photodynamic therapy (PDT). The efficacy of tumor elimination was confirmed through cellular and animal experiments, demonstrating the synergistic effectiveness of PTT and PDT. Importantly, no tumor regrowth was observed for 30 days after synergistic treatment. These results highlight the potential of combining photodynamic and photothermal therapies in nanomaterials for effective tumor therapy, offering a novel approach to tumor catalytic-photothermal therapy utilizing nanomaterials. [ABSTRACT FROM AUTHOR]

Metallic molybdenum sulfide (1T-MoS2) is considered as the most promising electrocatalyst for the acidic hydrogen evolution reaction (HER). Nevertheless, exploring a facile and effective approach for achieving high-purity 1T-MoS2 is still full of challenges. Herein, we demonstrate a two-dimensional material-assisted confined synthetic strategy, as an available method to construct and stabilize 1T-MoS2. During the hydrothermal process, the interaction between the N source and MoS2 is largely enhanced in a two-dimensional confined reactor, formed by reduced graphene oxides, successfully obtaining a high concentration of 90.1% of 1T-MoS2, named N-MoS2/rGO. The optimal N-MoS2/rGO nanosheets require a low overpotential (130 mV) to reach a current density of 10 mA·cm–2 and a low Tafel slope of 46.5 mV·dec–1. Additionally, they also exhibit high stability for at least 12 h in an acidic electrolyte maintaining 84.2% of the 1T-MoS2 phase. This work opens up an avenue to construct two-dimensional metastable materials for advanced catalysis. [ABSTRACT FROM AUTHOR]

Thisstudy investigated how a natural sphalerite (NS) photocatalyst,under visible light irradiation, supports photocatalytic bacterialinactivation. This was done by comparing parent E.coliBW25113, and its two isogenic single-gene knock-outmutants, E. coliJW0797-1 (dps–mutant) and JW1721-1 (katE–mutant), where both dpsand KatEgenes are likely related to H2O2production. NS could inactivate approximately 5-, 7- and 7-log of E. coliBW25113, JW0797-1, and JW1721-1 within 6h irradiation, respectively. The two isogenic mutants were more susceptibleto photocatalysis than the parental strain because of their lack ofa defense system against H2O2oxidative stress.The ability of in situresultant H2O2to serve as a defense against photocatalytic inactivationwas also confirmed using scavenging experiments and partition systemexperiments. Studying catalase activity further revealed that in situH2O2played an important rolein these inactivation processes. The destruction of bacterial cellsfrom the cell envelope to the intracellular components was also observedusing field emission-scanning electron microscopy. Moreover, FT-IRwas used to monitor bacterial cell decomposition, key functional groupevolution, and bacterial cell structures. This is the first studyto investigate the photocatalytic inactivation mechanism of E. coliusing single-gene deletion mutants undervisible light irradiation. [ABSTRACT FROM AUTHOR]

Compared to planar carbazole, the molecular conjugation of iminodibenzyl (Id) was destroyed by a C-C bond and a twisted structure was formed, which exhibited blue-shifted ultralong phosphorescence with a lifetime of 402 ms in a crystal under ambient conditions. For the presence of an oscillating C-C bond between the two benzene rings in Id, more than one molecular configuration in the crystal was discovered by X-ray single-crystal analysis. Moreover, its ultralong phosphorescence color changed from blue to green by varying the excitation wavelength in solution at 77 K. Theoretical calculations also confirmed that different molecular configurations had certain impact on the phosphorescent photophysical properties. This result will allow a major step forward in expanding the scope of ultralong organic phosphorescent (UOP) materials, building a bridge to realize the relationship between molecular structure and UOP property.

A systematic approach was developed to understand, in-depth, the mechanisms involved during the inactivation of bacterial cells using photoelectrocatalytic (PEC) processes with Escherichia coli K-12 as the model microorganism. The bacterial cells were found to be inactivated and decomposed primarily due to attack from photogenerated H2O2. Extracellular reactive oxygen species (ROSs), such as H2O2, may penetrate into the bacterial cell and cause dramatically elevated intracellular ROSs levels, which would overwhelm the antioxidative capacity of bacterial protective enzymes such as superoxide dismutase and catalase. The activities of these two enzymes were found to decrease due to the ROSs attacks during PEC inactivation. Bacterial cell wall damage was then observed, including loss of cell membrane integrity and increased permeability, followed by the decomposition of cell envelope (demonstrated by scanning electronic microscope images). One of the bacterial building blocks, protein, was found to be oxidatively damaged due to the ROSs attacks, as well. Leakage of cytoplasm and biomolecules (bacterial building blocks such as proteins and nucleic acids) were evident during prolonged PEC inactivation process. The leaked cytoplasmic substances and cell debris could be further degraded and, ultimately, mineralized with prolonged PEC treatment.

A series of novel well-defined Ag/AgX (X = Cl, Br, I) loaded carbon nanotubes (CNTs) composite photocatalysts (Ag/AgX-CNTs) were fabricated for the first time via a facile ultrasonic assistant deposition-precipitation method at the room temperature (25 ± 1 °C). X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption analysis, scanning electron microscopy, and ultraviolet-visible light absorption spectra analysis were used to characterize the structure, morphology, and optical properties of the as-prepared photocatalysts. Results confirmed the existence of the direct interfacial contact between Ag/AgX nanoparticles and CNTs, and Ag/AgX-CNTs nanocomposites exhibit superior absorbance in the visible light (VL) region owing to the surface plasmon resonance (SPR) of Ag nanoparticles. The fabricated composite photocatalysts were employed to remove 2,4,6-tribromophenol (TBP) in aqueous phase. A remarkably enhanced VL photocatalytic degradation efficiency of Ag/AgX-CNTs nanocomposites was observed when compared to that of pure AgX or CNTs. The photocatalytic activity enhancement of Ag/AgX-CNTs was due to the effective electron transfer from photoexcited AgX and plasmon-excited Ag(0) nanoparticles to CNTs. This can effectively decrease the recombination of electron-hole pairs, lead to a prolonged lifetime of the photoholes that promotes the degradation efficiency.