Room-temperature synthesis of 2D-Ti3C2Tx nano-sheets by organic base treatment

The growing demand for improved electrochemical performance in energy storage systems has stimulated research into advanced two-dimensional (2D) materials for electrodes. In this work, we obtain a layered MXene compound by exfoliating a titanium aluminum carbide precursor using tetramethylammonium hydroxide (TMAOH) ions in a full room temperature process followed by manual shaking. The hexagonal crystal structure and composition of the layered materials are characterized using different techniques. X-Ray diffraction shows the formation of 2D nano-sheets before and after the TMAOH treatment via its characteristic (002) diffraction peak, bringing to light an increase in the interlayer spacing after treatment. Scanning electron microscopy images confirm the layered morphology, whose composition is determined by energy dispersive x-ray analysis for the bulk material and by x-ray photoelectron spectroscopy for the surface of the obtained compounds. This study demonstrates a promising route to enhance delamination of this MXene 2D material in a low-cost room-temperature approach

Upcycling Real Waste Mixed Lithium-Ion Batteries by Simultaneous Production of rGO and Lithium-Manganese-Rich Cathode Material

The direct synthesis of high-value products from end-of-life Li-ion batteries (LIBs), avoiding the complex and costly separation of the different elements, can be reached through a competitive recycling strategy. Here, we propose the simultaneous synthesis of reduced graphene oxide (rGO) and lithium-manganese-rich (Li1.2Mn0.55Ni0.15Co0.1O2 - LMR) cathode material from end-of-life LIBs. The electrode powder recovered after LIBs mechanical pretreatment was directly subjected to the Hummers’ method. This way, quantitative extraction of the target metals (Co, Ni, Mn) and oxidation of graphite to graphene oxide (GO) were simultaneously achieved, and a Mn-rich metal solution resulted after GO filtration, owing to the use of KMnO4 as an oxidizing agent. This solution, which would routinely constitute a heavy-metal liquid waste, was directly employed for the synthesis of Li1.2Mn0.55Ni0.15Co0.1O2 cathode material. XPS measurements demonstrate the presence in the synthesized LMR of Cu2+, SO42–, and SiO44– impurities, which were previously proposed as effective doping species and can thus explain the improved electrochemical performance of recovered LMR. The GO recovered by filtration was reduced to rGO by using ascorbic acid. To evaluate the role of graphite lithiation/delithiation during battery cycling on rGO production, the implemented synthesis procedure was replicated starting from commercial graphite and from the graphite recovered by a consolidated acidic–reductive leaching procedure for metals extraction. Raman and XPS analysis disclosed that cyclic lithiation/delithiation of graphite during battery life cycle facilitates the graphite exfoliation and thus significantly increases conversion to rGO

A case of myocardial infarction effectively treated by emergency coronary stenting soon after a Bentall-De Bono aortic surgery

Postoperative ischemia may complicate cardiac surgery, despite myocardial protection and recent technical developments. Its medical management in the intensive cardiac care unit is usually efficient, although sometimes it requires the revision of the surgical site. In other cases, urgent coronary angiography and subsequent coronary stenting may resolve the situation. Ostial stenosis of coronary anastomoses is a well-known uncommon but dramatic complication after aortic surgery causing myocardial ischemia. Cases of effort angina have been described several months after surgery, but in some cases, acute myocardial infarction may occur days or weeks after intervention. We here describe an anteroseptal ST-elevation myocardial infarction soon after a Bentall aortic root replacement due to compression of the left main ostium by surgical glue, which has been effectively treated by emergency coronary stenting. This case highlights the importance of a joint management of acute myocardial ischemia after cardiac surgery by the cardiac surgeon and the interventional cardiologist

Life threatening hemorrhage after cardiopulmonary bypass with bilivarudin

This is a case report on cardiopulmonary bypass performed with bivalirudin and characterized by a life threatening hemorrhag