Hierarchical PtCuMnP Nanoalloy for Efficient Hydrogen Evolution and Methanol Oxidation.

The higher amount of Pt usage and its poisoning in methanol oxidation reaction in acidic media is a major setback for methanol fuel cells. Herein, a promising dual application high-performance electrocatalyst has been developed for hydrogen evolution and methanol oxidation. A low Pt-content nanoalloy co-doped with Cu, Mn, and P is synthesized using a modified solvothermal process. Initially, ultrasmall ≈2.9 nm PtCuMnP nanoalloy is prepared on N-doped graphene-oxide support and subsequently, it is characterized using several analytical techniques and examined through electrochemical tests. Electrochemical results show that PtCuMnP/N-rGO has a low overpotential of 6.5 mV at 10 mA cm-2 in 0.3 m H2 SO4 and high mass activity for the hydrogen evolution reaction. For the methanol oxidation reaction, the PtCuMnP/N-rGO electrocatalyst exhibits robust performance. The mass activity of PtCuMnP/N-rGO is 6.790 mA mg-1 Pt , which is 7.43 times higher than that of commercial Pt/C (20% Pt). Moreover, in the chronoamperometry test, PtCuMnP/N-rGO shows exceptionally good stability and retains 72% of the initial current density even after 20,000 cycles. Furthermore, the PtCuMnP/N-rGO electrocatalyst exhibits outstanding performance for hydrogen evolution and methanol oxidation along with excellent anti-poisoning ability. Hence, the developed bifunctional electrocatalyst can be used efficiently for hydrogen evolution and methanol oxidation.

High Entropy Pr-Doped Hollow NiFeP Nanoflowers Inlaid on N-rGO for Efficient and Durable Electrodes for Lithium-Ion Batteries and Direct Borohydride Fuel Cells.

The selection and design of new electrode materials for energy conversion and storage are critical for improved performance, cost reduction, and mass manufacturing. A bifunctional anode with high catalytic activity and extended cycle stability is crucial for rechargeable lithium-ion batteries and direct borohydride fuel cells. Herein, a high entropy novel three-dimensional structured electrode with Pr-doped hollow NiFeP nanoflowers inlaid on N-rGO was prepared via a simple hydrothermal and self-assembly process. For optimization of Pr content, three (0.1, 0.5, and 0.8) different doping ratios were investigated. A lithium-ion battery assembled with NiPr0.5 FeP/N-rGO electrode achieved an outstanding specific capacity of 1.61 Ah g-1 at 0.2 A g-1 after 100 cycles with 99.3 % Coulombic efficiencies. A prolonged cycling stability of 1.02 Ah g-1 was maintained even after 1000 cycles at 0.5 A g-1 . In addition, a full cell battery with NiPr0.5 FeP/N-rGO∥LCO (Lithium cobalt oxide) delivered a promising cycling performance of 0.52 Ah g-1 after 200 cycles at 0.15 A g-1 . Subsequently, the NiPr0.5 FeP/N-rGO electrode in a direct borohydride fuel cell showed the highest peak power density of 93.70 mW cm-2 at 60 °C. Therefore, this work can be extended to develop advanced electrode for next-generation energy storage and conversion systems.