Recent advances in single-atom catalysts(SACs)for photocatalytic applications

Artificial photocatalysis represents a hopeful avenue for tackling the global crisis of environmental and energy sustainability.The crux of industrial application in photocatalysis lies in efficient photocatalysts that can inhibit the recombination of photogenerated charge carriers,thereby boost the efficiency of chemical reactions.In the past decade,single-atom catalysts(SACs)have been growing extremely rapidly and have become the forefront of photocatalysis owing to their superior utilization of metal atoms and outstanding catalytic activity.In this work,we provide an overview of the latest advancements and challenges in SACs for photocatalysis,focusing on the photocatalytic mechanisms,encompassing the generation,separation,migration,and surface extraction of photogenerated carriers.We also explore the design,synthesis,and characterization of SACs and introduce the progress of SACs for photocatalytic applications,such as water splitting and CO_(2)reduction.Lastly,we offer our personal perspectives on the opportunities and challenges of SACs in photocatalysis,aiming to provide insights into the future studies of SACs for photocatalytic applications.

Inhibition effects of a negative electret 5-FU patch on the growth of a hypertrophic scar

In this study,the hypertrophic scar（HS） model in rats was established.5-fluorouracil（5-FU）patch,-1000 V and-2000 V polypropylene（PP） electret 5-FU patches were prepared and applied onto the wound.The in vitro permeation experiment was performed using the Franz diffusion cell system to determine the permeation cumulative amount and retention amount of5-FU through/in scar skin.The inhibition effect of negative electret on growth of HS was studied by hematoxylin-eosin（HE） staining,Masson staining and the immunohistologicall methods.The permeation study indicated that a negative electret could enhance the permeation and retention of 5-FU through and in scar skin respectively.HE staining and Masson staining indicated a better effect for-1000 V and-2000 V electret 5-FU patches on HS inhibition after28 d post-wounding compared with 5-FU patch.The immunohistological study showed much more reduced expressions of collegan type I,collegan type III,TGF-β1 and HSP47 in scar tissue after application of negative electret 5-FU patches than those of 5-FU patch.A negative electret5-FU patch may be advantageous for HS treatment.

Defect-enhanced photocatalytic removal of dimethylarsinic acid over mixed-phase mesoporous TiO2

Much attention has been paid to the pollutant dimethylarsenic acid(DMA),because of its high toxicity even at very low doses.Although TiO2 photocatalytic oxidation(PCO)is one of the few effective methods for treating DMA-containing water,the efficient decomposition of DMA and simultaneous removal of toxic arsenic species remains a significant but challenging task.Here,defective mesoporous TiO2 with mixed-phase structure was synthesized and used as both photocatalyst and adsorbent for DMA removal.Due to the reduced band-gap and enhanced separation of photogenerated charge carriers,the oxygen-deficient TiO2 nanostructures exhibited 4.2 times higher PCO efficiency than commercial TiO2(P25).More importantly,the high surface area of the mesoporous TiO2 provided sufficient active sites for in-situ adsorption and reaction,resulting in the efficient removal of as-formed As(V).Combining the experimental and characterization results,the different roles of reactive species during PCO reactions were clarified.In the presence of hole(h+)as the dominant oxidation species,DMA was demethylated and transformed into MMA.Thereafter,MMA was subsequently reduced to As(Ⅲ)by photo-generated electrons.Superoxide radicals(O2·-)played a significant role in oxidizing As(Ⅲ)into As(Ⅴ),which was finally adsorptively removed by the mesoporous TiO2.