Panneerselvam Perumal

Designing cost-effective and highly efficient electrocatalysts for the oxygen evolution reaction (OER) under alkaline conditions remains a significant challenge for sustainable hydrogen production.

Electrochemical water splitting (EWS) has emerged as a promising and sustainable approach for high-purity hydrogen production, offering an effective pathway toward clean and renewable energy conversion. However, the sluggish reaction kinetics of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) demand the development of highly efficient and cost-effective bifunctional electrocatalysts based on earth-abundant materials. Herein, a manganese−cobalt Prussian blue analogue (MC-PBA) intercalated nickel hydroxide (NiOH) heterostructure was rationally engineered through a facile synthetic strategy to enhance alkaline water-splitting performance. The robust electronic interaction between MC-PBA and NiOH modulates the electronic structure of the active centers, accelerates interfacial charge transfer, and improves the adsorption/desorption energetics of catalytic intermediates. In addition, the intercalated heterostructure offers abundant exposed electroactive sites, improved electrolyte accessibility, and rapid ion diffusion pathways, thereby facilitating enhanced electrocatalytic kinetics. Consequently, the optimized MC-PBA@NiOH catalyst accomplishes low overpotentials of ∼740 mV for OER and ∼585 mV for HER at 100 mA cm−2, together with small Tafel slopes of 179 and 127 mV dec−1, respectively. Furthermore, the assembled alkaline electrolyzer involves a low cell voltage of 2.71 V to deliver 100 mA cm−2 with excellent long-term operational stability. The superior bifunctional catalytic activity originates from the synergistic coupling between the redox-active MC-PBA framework and conductive NiOH matrix, which collectively promotes electron-transfer kinetics and intrinsic catalytic activity. This work reveals an effective heterointerface engineering strategy for the development of progressive nonprecious electrocatalysts for efficient overall water splitting and sustainable hydrogen generation.

Hierarchical ZIF-67@CeVO ₄ integrates porous MOF architecture with redox-active CeVO ₄ , enabling rapid ion transport, enhanced charge storage, and outstanding cycling stability for advanced energy storage devices.

The establishment of highly efficient and stable bifunctional electrocatalysts is very important for the promotion of alkaline water electrolysis. In addition, a novel hybrid electrocatalyst, which consists of Cu–Mn–O (CMO) mixed metal oxides supported on CNTs, is presented. The CNTs allow for highly conductive pathways for effective charge transfer, which in turn improves structural integrity and better access to catalytically active sites. Structural and surface characterization techniques, including XRD, HR-SEM, HR-TEM, and XPS, confirm the successful synthesis of the CNT–CMO hybrid electrocatalyst with a strong interface between the mixed metal oxide and CNTs. The CNT–CMO hybrid electrocatalyst demonstrates excellent electrocatalytic activity in 1.0 M KOH with low overpotentials of 280 mV for the HER and 251 mV for the OER at 10 mA cm⁻², along with Tafel slopes of 93 mV dec⁻¹, respectively. Additionally, the CNT–CMO hybrid electrocatalyst exhibits a greatly increased surface area when compared to the pristine CMO electrocatalyst, thereby allowing for enhanced utilization of active sites. Above all else, the CNT–CMO hybrid electrocatalyst maintains a constant current density for more than 30 hours of nearly continuous electrolysis, suggesting that high stability of this catalyst exists. The enhanced performance of the electrocatalysts is the result of a synergistic relationship between the mixed valence Cu and Mn redox sites and the high conductivity of the CNT, which together create a compatible environment for the catalytic reaction kinetics. The results further support the use of CNT-supported CMO as an earth-abundant, bifunctional electrocatalyst material for overall water splitting in alkaline solutions.

Graphical representation of Cu-Zn-MOF/g-C ₃ N ₄ for ciprofloxacin detection.

As the global energy demand continues to rise, the need for sustainable materials becomes increasingly critical. Graphitic carbon nitride, which can be sourced from abundant resources, is an environmentally friendly option. When combined with transition and lanthanide elements, it forms a powerful hybrid material that provides structural integrity. A significant advancement in this area is the synthesis of a graphitic carbon nitride incorporated neodymium tungsten oxide (GCN@NW) nanocomposite through a hydrothermal method, intended for use in high-performance supercapacitors. Analytical techniques confirmed the crystallinity and morphology of the composite, while electrochemical assessments exemplify its pseudocapacitive behaviour. The composite exhibits an electrochemically active surface area of 0.13 × 10⁻³ cm² with a specific capacitance of 354.88 F g⁻¹ at 1 A g⁻¹. It retains 96.7% of its capacitance after 5000 cycles and has a low charge transfer resistance (R_ct) of 3.3 Ω. An asymmetric supercapacitor device GCN@NW-ASC was fabricated, which achieved a specific capacitance of 62.98 F g⁻¹ at 1 A g⁻¹. It established an impressive power density of 2605.74 kW kg⁻¹ and an energy density of 45.34 Wh kg⁻¹, while retaining 97.3% of its initial capacitance after 5000 cycles. These findings underscore the potential of advanced functional materials as eco-friendly candidates for future energy storage technologies.

Efficient and robust electrocatalysts are essential for advancing electrochemical water splitting (EWS) as a sustainable hydrogen production technology. Herein, we report a bimetallic iron-zirconium fumaric acid metal-organic framework (FZ-MOF) intercalated on boron nitride nanosheets (BNNs) as a high-performance catalyst for overall water splitting. The FZ-MOF offers a high density of molecularly dispersed active sites, while the fumaric acid linker ensures structural stability and optimal spatial exposure of these sites. Integration of BNNs significantly improves the conductivity and surface area, facilitating rapid charge transfer and efficient mass transport. Mechanistically, the Fe and Zr centers synergistically promote water molecule adsorption and activation, lowering the overpotentials for both the hydrogen and oxygen evolution reactions. The heterointerface between the MOF and BNNs further accelerates the reaction kinetics by providing abundant catalytic sites and efficient electron pathways. Electrochemical studies performed in 1 M KOH reveal excellent bifunctional performance: the hybrid catalyst exhibits overpotentials of 380 mV and 156 mV at 10 mA/cm² for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The system exhibits superior kinetics, which is evidenced by low Tafel slopes and minimum charge-transfer resistance accessed by electrochemical impedance spectroscopy (EIS). Additionally, a two-electrode electrolyzer built on symmetric FZ-MOF@BNNs electrodes displays overall water splitting at a 1.86 V (10 mA/cm²) cell voltage, including exceptional stability. This hybrid catalyst demonstrates low overpotentials, high current densities, and excellent durability, underscoring the potential of interface-engineered MOF composites for next-generation water-splitting applications.