Probing Carbocatalytic Activity of Carbon Nanodots for the Synthesis of Biologically Active Dihydro/Spiro/Glyco Quinazolinones and Aza-Michael Adducts

Herein, we report the fluorescent carbon dots as an effective and recyclable carbocatalyst for the generation of carbon–heteroatom bond leading to quinazolinone derivatives and aza-Michael adducts under mild reaction conditions. The results establish this nanoscale form of carbon as an alternative carbocatalyst for important acid catalyzed organic transformations. The mild surface acidity of carbon dots imparted by −COOH functionality could effectively catalyze the formation of synthetically challenging spiro/glycoquinazolinones under the present reaction conditions

Carbon Dots as Nanodispersants for Multiwalled Carbon Nanotubes: Reduced Cytotoxicity and Metal Nanoparticle Functionalization

The colloidal stabilization of multiwalled carbon nanotubes (MWCNTs) in an aqueous medium through noncovalent interactions has potential benefits toward the practical use of this one-dimensional carbonaceous material for biomedical applications. Here, we report that fluorescent carbon nanodots can efficiently function as dispersing agents in the preparation of stable aqueous suspensions of CNTs at significant concentrations (0.5 mg/mL). The amphiphilic nature of carbon dots with a hydrophobic graphitic core could effectively interact with the CNT surface, whereas hydrophilic oxygenated functionalization on the C-dot surface provided excellent water dispersibility. The resultant CNT-C-dot composite showed significantly reduced cytotoxicity compared to that of unmodified or protein-coated CNTs, as demonstrated by cell viability and proliferation assays. Furthermore, the reducing capability of C-dots could be envisaged toward the formation of a catalytically active metal nanoparticle-CNT-C-dot composite without the addition of any external reducing or stabilizing agents that showed excellent catalytic activity toward the reduction of <i>p</i>-nitrophenol in the presence of NaBH₄. Overall, the present work establishes C-dots as an efficient stabilizer for aqueous dispersions of CNTs, leading to an all-carbon nanocomposite that can be useful for different practical applications

Integrated halide perovskite photoelectrochemical cells with solar driven water splitting efficiency of 20.8

Achieving high solar to hydrogen STH efficiency concomitant with long term durability using low cost, scalable photo absorbers is a long standing challenge. Here we report the design and fabrication of a conductive adhesive barrier CAB that translates gt;99 of photoelectric power to chemical reactions. The CAB enables halide perovskite based photoelectrochemical cells with two different architectures that exhibit record STH efficiencies. The first, a co planar photocathode photoanode architecture, achieved an STH efficiency of 13.4 and 16.3 amp; 8201;h to t60, solely limited by the hygroscopic hole transport layer in the n i p device. The second was formed using a monolithic stacked silicon perovskite tandem, with a peak STH efficiency of 20.8 and 102 amp; 8201;h of continuous operation before t60 under AM 1.5G illumination. These advances will lead to efficient, durable, and low cost solar driven water splitting technology with multifunctional barrier

Sharing aquatic genetic resources across jurisdictions: playing ‘chicken’ in the sea

International regimes regulating access and benefit sharing were originally designed to promote conservation and fairness objectives concerning the use of the world’s biological resources for their genetic material value. These regimes determine from whom permission is required to take the resources and who obtains the benefits of their use. They have evolved separate frameworks in three distinct jurisdictional areas—within national jurisdiction, beyond national jurisdiction and in the Antarctic Treaty Area. This article argues that if these regimes continue to evolve separately, there is a strong temptation for countries to play ‘chicken’ with biological resource governance through forum shopping or opting out of agreements that do not suit their political ends. Using game theory and a transgenic tilapia fish example incorporating genetic material from the three jurisdictional areas, it illustrates the legal and ethical dilemmas that can arise from the territorial (jurisdictional) approach to access and benefit sharing—to the detriment of fairness and conservation in tilapia’s countries of origin. Tilapias are known as the ‘chicken of the sea’ because they dominate global farmed production and developing countries depend on them as their primary source of protein, livelihoods and trade. This means there will be serious consequences if the regimes do not achieve their fairness and conservation objectives for sharing their genetic material. This article concludes that a purpose-driven cooperative governance approach can sidestep the game of chicken and promote fairer and more conservation focused outcomes than the current jurisdictional approach for the developing country providers of migratory aquatic resources