One-Pot Synthesis of Bismuth Sulfide Nanostructures as an Active Electrode Material for Aqueous Hybrid Capacitors

The high theoretical capacity of Bi2S3 shows high promise as a negative electrode material for energy storage devices. Herein, we investigate a facile, one-step chemical precipitation method using common organic solvents, such as acetone, ethanol, and isopropanol, for the synthesis of Bi2S3 nanostructures. The nanospherical Bi2S3 from acetone (Bi2S3-A) presents the most balanced electrochemical properties, exhibiting a high specific capacity of 181 mAh g−1 at 1 A g−1 and decent rate capability. Additionally, Bi2S3-A is used as a negative electrode in an aqueous hybrid system with an activated carbon positive electrode, demonstrating a capacitance of 86 F g−1, a specific energy of 7.6 Wh kg−1, and an initial capacity retention of 74% after 1000 cycles

Synthesis of Polypyrrole/Reduced Graphene Oxide Hybrids via Hydrothermal Treatment for Energy Storage Applications

Herein, we propose hydrothermal treatment as a facile and environmentally friendly approach for the synthesis of polypyrrole/reduced graphene oxide hybrids. A series of self-assembled hybrid materials with different component mass ratios of conductive polymer to graphene oxide was prepared. The morphology, porous structure, chemical composition and electrochemical performance of the synthesized hybrids as electrode materials for supercapacitors were investigated. Nitrogen sorption analysis at 77 K revealed significant changes in the textural development of the synthesized materials, presenting specific surface areas ranging from 25 to 199 m2 g−1. The combination of the pseudocapacitive polypyrrole and robust graphene material resulted in hybrids with excellent electrochemical properties, which achieved specific capacitances as high as 198 F g−1 at a current density of 20 A g−1 and retained up to 92% of their initial capacitance after 3000 charge–discharge cycles. We found that a suitable morphology and chemical composition are key factors that determine the electrochemical properties of polypyrrole/reduced graphene oxide hybrid materials

The Polish Military Cemetery at Monte Cassino-Why and How

The Polish Military Cemetery at Monte Cassino is sui generis. Although three other Second World War Polish military cemeteries exist in Italy (in Cassamassima, in Loreto and in Bologna), and although the latter two actually contain more burials, the Monte Cassino cemetery cemetery is, unquestionably, the most impressive. It was specifically built by a representative of an increasingly powerless nation to be impressive and monumental on a grand scale. The premise of the thesis is that it was built to mythologize an event of then-contemporary history in order that the event be transformed into a tangible and “touchable” source of national inspiration. The evidence uncovered in the course of the research makes clear that the individual whose brainchild the cemetery was- General Władysław Anders- believed that a physical structure, physically quite distant and even likely to never be visited by many of the fallen’s countrymen, could nevertheless become a national symbol. The symbol would embody, in a stone structure, a version of national epic that would resonate even with those who might never see it. The premise of this research is that a historical act can be mythologized, and, therefore, perpetuated by a tangible object- itself the work of human hands. The research is distilled into two written parts. First, a context is provided through an examination of the role of Poland’s Government-in-Exile and its armed forces from the beginnings of the Second World War through to the last Battle of Monte Cassino, fought in Italy from 11 to 18 May 1944. Poland, while a major protagonist in the Second World War, was not one of the „The Big Three” powers which determined the post-war order, hence the Polish context is itself examined within the overall context of the „Grand Alliance.” Also examined is the creation of the Polish Army’s 2nd Corps, which, from its roots in Soviet captivity in 1939-41, became the „army in exile” which fought at Monte Cassino. The preceding context is derived from secondary sources. Second, the decision to build a suitable monumental cemetery is traced to its origins. Hours after the conclusion of the Battle on 18 May 1944, General Anders publically committed to building such a monument. Examination of archival sources reveals, clearly, that Anders elevated the building of the Monte Cassino cemetery to a priority that none of the other Western Allies accorded to their own dead. In the midst of continuing combat operations, the Polish 2nd Corps found the means and time to build a final resting place for comrades who had fallen in a battle which was renowned throughout the Western world. The research has uncovered previously unknown details about the building of the cemetery and the ingenious means employed by a small team with little resources to properly commemorate Poland’s Monte Cassino dead. Finally, the thesis attempts to answer the rhetorical questions posed by the extraordinary fait accomplis of a completed memorial, consecrated on 1 September 1945. The most compelling question is, „Why?” Why was it adjudged important to build a permanent cemetery with such alacrity, an alacrity not remotely displayed by wealthier and more powerful Allied armies. This decision is all the more poignant because it was almost certainly evident to General Anders that the looming outline of the postwar order would not be favorable to the cause for which his men fought and died. The inescapable conclusion is that Anders deliberately set out to build a tangible Polish national symbol in a foreign land, a symbol which would remind future generations of Poles of a great deed which, for a moment, had placed them in the world’s spotlight. The creation of the Polish Military Cemetery at Monte Cassino is thus a case study, and a recent one, at that, of how historical events be mythologized, and, therefore, perpetuated, in this case, through the means of a tangible object- itself the work of human hands.The Polish Military Cemetery at Monte Cassino is sui generis. Although three other Second World War Polish military cemeteries exist in Italy (in Cassamassima, in Loreto and in Bologna), and although the latter two actually contain more burials, the Monte Cassino cemetery cemetery is, unquestionably, the most impressive. It was specifically built by a representative of an increasingly powerless nation to be impressive and monumental on a grand scale. The premise of the thesis is that it was built to mythologize an event of then-contemporary history in order that the event be transformed into a tangible and “touchable” source of national inspiration. The evidence uncovered in the course of the research makes clear that the individual whose brainchild the cemetery was- General Władysław Anders- believed that a physical structure, physically quite distant and even likely to never be visited by many of the fallen’s countrymen, could nevertheless become a national symbol. The symbol would embody, in a stone structure, a version of national epic that would resonate even with those who might never see it. The premise of this research is that a historical act can be mythologized, and, therefore, perpetuated by a tangible object- itself the work of human hands. The research is distilled into two written parts. First, a context is provided through an examination of the role of Poland’s Government-in-Exile and its armed forces from the beginnings of the Second World War through to the last Battle of Monte Cassino, fought in Italy from 11 to 18 May 1944. Poland, while a major protagonist in the Second World War, was not one of the „The Big Three” powers which determined the post-war order, hence the Polish context is itself examined within the overall context of the „Grand Alliance.” Also examined is the creation of the Polish Army’s 2nd Corps, which, from its roots in Soviet captivity in 1939-41, became the „army in exile” which fought at Monte Cassino. The preceding context is derived from secondary sources. Second, the decision to build a suitable monumental cemetery is traced to its origins. Hours after the conclusion of the Battle on 18 May 1944, General Anders publically committed to building such a monument. Examination of archival sources reveals, clearly, that Anders elevated the building of the Monte Cassino cemetery to a priority that none of the other Western Allies accorded to their own dead. In the midst of continuing combat operations, the Polish 2nd Corps found the means and time to build a final resting place for comrades who had fallen in a battle which was renowned throughout the Western world. The research has uncovered previously unknown details about the building of the cemetery and the ingenious means employed by a small team with little resources to properly commemorate Poland’s Monte Cassino dead. Finally, the thesis attempts to answer the rhetorical questions posed by the extraordinary fait accomplis of a completed memorial, consecrated on 1 September 1945. The most compelling question is, „Why?” Why was it adjudged important to build a permanent cemetery with such alacrity, an alacrity not remotely displayed by wealthier and more powerful Allied armies. This decision is all the more poignant because it was almost certainly evident to General Anders that the looming outline of the postwar order would not be favorable to the cause for which his men fought and died. The inescapable conclusion is that Anders deliberately set out to build a tangible Polish national symbol in a foreign land, a symbol which would remind future generations of Poles of a great deed which, for a moment, had placed them in the world’s spotlight. The creation of the Polish Military Cemetery at Monte Cassino is thus a case study, and a recent one, at that, of how historical events be mythologized, and, therefore, perpetuated, in this case, through the means of a tangible object- itself the work of human hands

DataSheet1_Synthesis strategies of iron nitrides at carbon cloth as battery-like electrode for hybrid supercapacitors.PDF

In recent years, hybrid supercapacitors (HSCs) or supercapatteries which combine a capacitor-type electrode with an electrode based on materials exhibiting a Faradaic (battery-like) response have been intensively investigated for next-generation energy storage applications. HSCs attracted great attention due to a significant increase of maximum energy density stored while providing stable long-term performance and good rate capability. However, the electrochemical performance of the device is closely related to the inherent properties of the electrode material, including morphology and structure. In this paper, we present synthesis protocols for iron oxide/hydrophilic carbon cloth (Fe2O3@hCC) composite electrodes and their electrochemical performance as a negative electrode operating in an alkaline electrolyte. Two environmentally friendly, scalable and facile synthesis approaches were applied, including hydrothermal treatment and direct electrodeposition. Next, the Fe2O3@hCC electrodes were treated to convert iron oxide to iron nitride (Fe2N). The results showed that the synthesis of the precursor for iron nitride has a direct impact on morphology, crystalline structure and electrochemical performance. Furthermore, the amorphous Fe2N obtained from electrodeposition exhibited significantly better Faradaic behavior, achieving a specific capacity up to 186 mAh g-1, 66% higher than the composite electrode with Fe2N from the hydrothermal approach.</p

A Promising Electrochemical Platform for Dopamine and Uric Acid Detection Based on a Polyaniline/Iron Oxide-Tin Oxide/Reduced Graphene Oxide Ternary Composite

A ternary polyaniline/Fe2O3-SnO2/reduced graphene oxide (PFSG) nanocomposite was prepared using a simple two-step hydrothermal treatment. The composite was applied as a glassy carbon electrode modifier (GCE) to enhance dopamine (DA) and uric acid (UA) detection. The ternary PFSG composite was compared with its binary precursor Fe2O3-SnO2/reduced graphene oxide (FSG). The influence of the modified GCE electrodes on their performance as a sensing platform was determined. GCE/PFSG showed better sensing parameters than GCE/FSG due to the introduction of polyaniline (PANI), increasing the electrocatalytic properties of the electrode towards the detected analytes. GCE/PFSG enabled the detection of low concentrations of DA (0.076 &micro;M) and UA (1.6 &micro;M). The peak potential separation between DA and UA was very good (180 mV). Moreover, the DA oxidation peak was unaffected even if the concentration of UA was ten times higher. The fabricated sensor showed excellent performance in the simultaneous detection with DA and UA limits of detection: LODDA = 0.15 &micro;M and LODUA = 6.4 &micro;M, and outstanding long-term stability towards DA and UA, holding 100% and 90% of their initial signals respectively, after one month of use

Hydrothermal nitrogen doping of anthracene oil-derived activated carbons for wide voltage asymmetric capacitors

This work focused on the development of doping procedures to introduce nitrogen functionalities on an activated carbon derived from anthracene oil to be subsequently used on wide voltage asymmetric capacitors. For that, ammonia solution was used and different hydrothermal conditions applied. Tailoring the temperature treatment (120 and 180 °C), nitrogen-doped activated carbons (N-ACs) with different nitrogen content (5.6 and 4.1 at. %) and diverse speciation were obtained. N-ACs exhibited excellent capacitive behaviour and long-life cycle in a three-electrode cell using KOH aqueous solution as electrolyte. The significant capacitance value of 291 F g-1 at 0.2 A g-1 was achieved by the N-AC obtained at 180 °C. Furthermore, full carbon asymmetric supercapacitors incorporating N-ACs as negative electrodes were assembled, and an operating voltage window of 1.3 V in 6 M KOH solution established. As a result, high energy densities were achieved in the devices, particularly in that including N-AC-180. Electrochemical tests revealed that pyridinic and quaternary nitrogen species of N-ACs play a critical role in the excellent asymmetric supercapacitor electrochemical performance, including improvement of conductivity and specific capacitance