Balaram Sahoo

Rationally designed, multifunctional, highly efficient, robust, and cost-effective non-precious-metal-based bifunctional oxygen electrocatalysts have attracted substantial interest in the field of clean energy over the last few decades. A catalyst designed with surface charge-storage-like properties is of great significance for sustainable Zn–air batteries. However, preparing such an interface requires complex synthesis and purification. Here, we used binary CoNi alloy nanoparticles as nuclei in a single-step pyrolytic synthesis to create a novel hybrid of nickel-anchored nitrogen-doped carbon nanotubes (CNTs). The improved sample showcases a bifunctional interface capable of both oxygen evolution and reduction, along with efficient EDLC-type surface charge storage. As a result, the hybrid structure exhibits capacitive characteristics, making it a potential candidate for supercapacitor-assisted zinc–air battery configurations. This superstructure (CoNi/CNTs) enabled ZAB to reach an open-circuit voltage of 1.447 V and a power density of 141.29 mW/cm2. This promising performance is attributed to the active surfaces of the N-doped compartmentalized CNTs. Furthermore, the synergistic interactions between the catalytically active carbon centers, anchoring ultrasmall Ni clusters, and CoNi alloy nanoparticles further improve the catalytic activity. Our findings emphasize the potential for clean-energy applications by demonstrating the practical benefits of integrating charge-storage-like properties in the catalyst architecture for sustainable Zn–air batteries.

Controlling nitrogen functionalities in graphene are crucial for high-performance supercapacitors. In this study, we report the scalable synthesis of nitrogen-doped reduced graphene oxide (N-rGO) via a hydrothermal process using readily available inorganic precursors in an aqueous phase, enabling controlled manipulation of nitrogen functionalities. The optimized N-rGO (GO:aqueous NH ₃ = 1:6) exhibits a areal capacitance of 0.4 F cm ⁻² at a scan rate of 5 mV s ⁻¹ . In a symmetric two-electrode system, N-rGO delivers a high specific capacitance of 532 F g ⁻¹ , along with an energy density of 41 Wh kg ⁻¹ and a power density of 375 W kg ⁻¹ at 0.5 A g ⁻¹ , with a capacitance retention of ∼78% after 10,000 cycles at 1.96 V. These performance metrics are attributed to an optimal defect concentration combined with a high proportion of amino and pyrrolic nitrogen functionalities. Quantum capacitance calculations reveal an enhanced electronic density of states near the Fermi level, thereby improving charge storage performance.

Magnetostriction behavior of Zn ²⁺ - and Mg ²⁺ -substituted NiFe ₂ O ₄ samples are impacted differently although isovalent cations are substituted for the same element (Ni ²⁺ ).

A dual heteroatom (N,P)-doped carbon nanostructure grafted on nickel nanoparticles synergistically enhances the catalytic effect for H ₂ O adsorption during the hydrogen evolution reaction (HER).