Sankaran Esakki Muthu

Anion exchange membrane water electrolysis (AEMWE) is a promising route to low-cost, noble-metal-free green hydrogen production, but its performance remains limited by the sluggish kinetics of the anodic oxygen evolution reaction (OER) and by the poor intrinsic electrical conductivity of many candidate catalyst supports. Covalent organic frameworks (COFs) offer crystalline, highly porous, and chemically tunable platforms for anchoring transition-metal and single-atom active sites, but pristine COFs are electrically insulating. This review summarizes recent progress in conductive COF-based hybrid anodes for AEMWE, covering the fundamentals of AEMWE operation, COF chemistry and synthesis, strategies for engineering electrical conductivity (hybridization with MXene, graphene, carbon nanotubes, heteroatom doping, metal coordination, defect and interface engineering), the OER mechanism on COF-based active sites, electrochemical performance metrics, comparative benchmarking against commercial and other non-precious-metal catalysts, computational and machine-learning-assisted design approaches, and the remaining challenges in stability, scalability, and cost that must be addressed before commercialization.

This study reports the synthesis and comprehensive characterization of a novel 5% cadmium-doped cerium oxide/reduced graphene oxide (5% Cd-CeO₂/rGO) nanocomposite for the enhanced visible-light-driven photocatalytic degradation of methyl orange (MO). The nanocomposite was prepared using a simple co-precipitation method followed by thermal reduction, which integrates the excellent electron-transport properties of reduced graphene oxide (rGO) with the oxygen-vacancy-rich characteristics of Cd-doped CeO₂, resulting in improved photocatalytic performance. The successful synthesis of the nanocomposite and the direct interaction between the rGO sheets and ultrafine CeO₂ nanoparticles were verified through structural and morphological analyses using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM). XPS results indicated an increase in the Ce³⁺ concentration and oxygen vacancy density after Cd doping and rGO incorporation, both of which play a crucial role in enhancing photocatalytic activity. Under visible-light irradiation, the 5% Cd-CeO₂/rGO nanocomposite exhibited substantially higher photocatalytic activity and methyl orange (MO) degradation efficiency than pristine CeO₂ and reduced graphene oxide (rGO). The improved photocatalytic performance demonstrates the beneficial role of combining metal-ion doping with conductive carbon supports to facilitate charge separation and electron transport in semiconductor photocatalysts. The developed nanocomposite also shows promising potential for the design of next-generation semiconductor-based materials for photocatalytic, energy conversion, and optoelectronic applications.

The structural and magnetic properties of the Co2MnAl full Heusler alloy is investigated withemphasis on disorder-driven magnetic behavior. X-ray diffraction confirms the formation of a orderedL21 cubic structure. Magnetization measurements reveal soft ferromagnetic behavior with a Curietemperature of 𝑇𝑐 ≈ 696 K. The thermal demagnetization follows modified Bloch’s law at lowtemperatures, indicating dominant spin-wave contributions. A clear deviation from Curie–Weissbehavior above 𝑇𝑐 is observed, indicating the presence of short-range ferromagnetic correlations.The existence of a finite temperature range between 𝑇𝑐 and the Griffiths temperature (𝑇𝐺 ≈ 862 K)confirms the emergence of a Griffiths-like phase. The extracted Griffiths exponent 𝜆𝐺 ≈ 0.92764suggests magnetic inhomogeneity in Co2MnAl.

Next-generation energy storage systems demand advanced electrode materials that offer both high performance and long-term sustainability.