We have synthesized a novel ferromagnetic material by coating α-Fe 2 o 3 nanoparticles with N-doped carbon matrix using a simple combustion method. Expired paracetamol drugs are used as nitrogen and carbon source. This α-Fe 2 o 3 /NC shows ferromagnetic property due to the incorporation of oxygen defects. When used as the Li-ion battery anode, α-Fe 2 o 3 /NC shows higher capacity compared to commercial α-Fe 2 o 3 due to the occurrence of both intercalation and conversion reaction. Further, application of magnetic field at the anode of the freshly assembled cell at the first charge-discharge cycle, results in ~two-fold enhancement in specific capacity. For the cycled cell also, increase in the capacity from 80 mAh. g −1 to 150 mAh. g −1 at 5 A. g −1 is observed during the application of magnetic field at the 501 st charging cycle. This improved performance is attributed to the field-dependent enhancement of diffusion and convection due to the magnetohydrodynamic effect. Further, application of the magnetic field at 1001 st , 1501 st and 1751 st charging cycles shows improved LIB performance. We can show that not only the magnetic field, magnetic properties of the anode α-Fe 2 o 3 /NC also play a crucial role in influencing the battery performance. Moreover, utilization of expired drug helps in dramatically reducing pollution caused by its disposal. The depletion of fossil fuels and the concomitant increase of CO 2 effluence have stimulated the need for alternative energy technologies for the future society. One of the promising solutions is to shift from the existing fuel-powered vehicles to battery-powered ones. However, this demands high capacity lithium-ion batteries (LIBs), which has engendered the need for the research of alternative anode materials 1-4. Amongst the metal oxides, α-Fe 2 O 3 is widely studied due to its high theoretical capacity, excellent catalytic properties, electrochemical and thermal stability 3,5-8. During Li + ion insertion in bulk α-Fe 2 O 3 , iron atoms jump from tetrahedral sites to octahedral sites and result in face centred cubic Fe 3 O 4 structure and produces Fe and Li 2 O matrix 9. But this mechanism does not hold good for its nano counterpart 10. The reduced particle size of α-Fe 2 O 3 nanoparticles results in intercalation without the change in the crystal structure, thereby facilitates better Li + ion storage and durability in α-Fe 2 O 3 anode 10,11. But, the main drawback of α-Fe 2 O 3 is its large volume expansion which leads to the low durability and capacity fading over the cycles. Incorporation of high surface area porous carbon matrix helps to accommodate the volume expansion during lithiation/delithiation process 5,7,12. Compared to pure carbon matrix, N-doping on carbon helps in better interaction of Li and N doped carbon due to the higher electronegativity of nitrogen and change in the electron density near carbon atoms. This eventually lead to better stability of LIBs 1,12,13. Despite these, lithium deposition at anode and increasing concentration overpotential caus...

Developing a nonenzymatic sweat sensor for selective determination of glucose and lactate holds great significance in clinical diagnostics. Among various catalysts, transition metal-based metal-organic frameworks (MOF) have recently drawn more attention due to their tunable porosity and enhanced electrocatalytic activity. The presence of solvent molecule in the framework can influence both structural and electrochemical properties. In the present work, Copper-terephthalate (CuBDC) MOF was synthesized in a solvothermal method with different time durations. The effect of coordinated solvent molecules on the metal centre on structural and electrocatalytic properties was systematically investigated using various characterization techniques. As most of the copper-based composites reported so far showed performance in an alkaline medium, we demonstrate the detection of glucose and lactate in a neutral medium that enables direct analyte measurement from the body fluid. Electrochemical studies indicate that the solvated structure shows superior sensitivity to the desolvated MOF for glucose and lactate. The high sensitivity of solvated MOF is attributed to the favourable solvent exchange mechanism and ion diffusion through the channels of MOF. Furthermore, CuBDC12E and CuBDC48E show negligible interference toward competing analytes. The proposed sensor also exhibits good sensing performance in artificial sweat, making it suitable for a non-invasive, practical sweat sensor.

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