可再生Fe3O4/CuFeS2/生物质复合降解柱对有机染料的处理性能

采用具有单分散性、 平均粒径分别为(200±0.5) nm和(6.5±0.5) nm的Fe₃O₄纳米微球和CuFeS₂纳米晶与生物质废弃物复合制备出Fe₃O₄/CuFeS₂/生物质复合降解柱. 该降解柱能高效处理有机染料亚甲基蓝(MB)和罗丹明B(RhB), 降解率超过90%. CuFeS₂中的Cu⁺能显著促进芬顿反应, 而Fe₃O₄较强的磁性有利于催化剂的回收. 更重要的是, 再生后的复合柱对有机染料的降解率没有明显降低, 仍可达90%以上. 此外, 该降解柱可充分利用生物质废弃物, 解决其回收利用的难题.     

A Telomerase-Assisted Strategy for Regeneration of DNA Nanomachines in Living Cells

DNA nanomachines have been engineered into diverse personalized devices for diagnostic imaging of biomarkers; however, the regeneration of DNA nanomachines in living cells remains challenging. Here, we report an ingenious DNA nanomachine that can implement telomerase (TE)-activated regeneration in living cells. Upon apurinic/apyrimidinic endonuclease 1 (APE1)-responsive initiation of the nanomachine, the walker of the nanomachine moves along tracks regenerated by TE, generating multiply amplified signals through which APE1 can be imaged in situ. Additionally, augmentation of the signal due to the regeneration of the nanomachines could reveal differential expression of TE in different cell lines. To the best of our knowledge, this is the first proof-of-concept demonstration of the use of biomarkers to assist in the regeneration of nanomachines in living cells. This study offers a new paradigm for the development of more applicable and efficient DNA nanomachines.     

Highly Efficient Decomposition of Perfluorocarbons for over 1000 Hours via Active Site Regeneration

Tetrafluoromethane (CF₄), the simplest perfluorocarbon (PFC), has the potential to exacerbate global warming. Catalytic hydrolysis is a viable method to degrade CF₄, but fluorine poisoning severely restricts both the catalytic performance and catalyst lifetime. In this study, Ga is introduced to effectively assists the defluorination of poisoned Al active sites, leading to highly efficient CF₄ decomposition at 600 °C with a catalytic lifetime exceeding 1,000 hours. ²⁷Al and ⁷¹Ga magic-angle spinning nuclear magnetic resonance spectroscopy (MAS NMR) showed that the introduced Ga exists as tetracoordinated Ga sites (Ga_IV), which readily dissociate water to form Ga−OH. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density function theory (DFT) calculations confirmed that Ga−OH assists the defluorination of poisoned Al active sites via a dehydration-like process. As a result, the Ga/Al₂O₃ catalyst achieved 100 % CF₄ decomposition keeping an ultra-long catalytic lifetime and outperforming reported results. This work proposes a new approach for efficient and long-term CF₄ decomposition by promoting the regeneration of active sites.