Prakash Chandra Mondal

We investigate the charge transport in Re( i ) carbonyl organometallic compounds forming single-molecule junctions between gold contacts. Using the Landauer formalism and the Marcus theory, the charge transport phenomena are systematically analyzed.

Gold nanoparticles (Au NPs) supported on ordered mesoporous silica have attracted significant attention as robust nanocatalysts. In this study, high‐gold‐content three‐dimensional (3D) mesoporous silica (KIT‐6‐Au NPs) was synthesized, which exhibited a 3D cubic Ia3d mesostructure with uniformly dispersed Au NPs (∼8 nm) predominantly exposing the (111) facets. Structural analyses were conducted by Brunauer–Emmett–Teller surface area measurement, Raman spectroscopy, solid‐state Si ²⁹ NMR spectroscopy, Transmission electron microscopy, x‐ray diffraction, x‐ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectroscopy, confirming high gold loading 15.5 wt% and strong metal–support interaction. Catalytic performance was evaluated through the reduction of 4‐nitrophenol (4‐NP) with NaBH ₄ as a model reaction, exhibiting a maximum apparent rate constant of 0.0086 ± 0.0002 s ^{− 1} at 25°C. It surpasses comparable Au–mesoporous silica systems and is competitive with other silica‐supported metallic nanocatalysts. The findings further confirm that the reduction of 4‐NP by NaBH ₄ in the presence of the KIT‐6‐Au NP catalyst proceeds via a heterogeneous catalytic pathway and that the catalyst is structurally robust under the reaction conditions. This work highlights the potential of facet‐engineered, high‐loading Au NPs integrated within a 3D mesoporous silica framework as an efficient catalyst capable of promoting diverse reactions under mild conditions.

Tuning the electronic structure modulates resistive switching behavior, and high-performance molecular memory in ferrocene-based devices.

Precise control over covalent functionalization at organic-inorganic interfaces remains a critical challenge for highperformance energy applications. Here, we report a series of covalently integrated hybrid electrodes in which electroactive organic...

Memory is the backbone of modern computing systems, enabling efficient data storage and functionality. Among emerging nonvolatile memories, resistive random‐access memory (RRAM) has garnered significant attention due to its fast switching speed, high scalability, low power consumption, and CMOS compatibility, which makes it suitable for neuromorphic architectures. RRAM operation relies on the history‐dependent modulation of resistance in a dielectric layer in response to external stimuli. Recent developments have focused on the wide array of memory‐active materials, particularly inorganic and organic compounds, each offering distinct operational modes, tunable switching characteristics, and pathways toward multilevel, low‐power, and neuromorphic memory devices. This review summarizes the latest advances in oxide‐based RRAM devices, a foundational platform that has driven critical breakthroughs from the initial memristor concept to modern filamentary switching mechanisms. It compares these developments with conventional memory technologies and discusses current challenges and future prospects. Furthermore, we highlight its emerging role in neuromorphic computing, underscoring its potential to revolutionize brain‐inspired hardware.

Electrochromic devices employing benzyl viologen demonstrate clear counterion-dependent behavior, allowing a systematic assessment of performance parameters such as cycling stability and coloration efficiency.

Molecular functionalization of magnetic oxide nanoparticles presents a powerful strategy for interfacial engineering, enabling the emergence of exotic magnetic phenomena. While non‐covalent approaches have been widely explored, they often fail to provide robust interfaces for real applications. We report here covalent surface modification of cobalt ferrite (CoFe ₂ O ₄ ) nanoparticles (NPs) using a series of judiciously selected aryl diazonium salts to achieve a higher degree of surface functionalization and strong interfacial electronic coupling. This modification establishes robust carbon–metal (C–M) covalent bonds at the nanoparticle–molecule interface, conferring chemical stability and tunable magnetic properties. Notably, π‐electron‐rich aryl compounds transform pristine superparamagnetic CoFe ₂ O ₄ NPs into room‐temperature ferromagnets, with a significant increase in coercivity, remanent magnetization, and saturation magnetization, attributed to enhanced surface spin ordering on different sublattices and elevated effective anisotropy. Zero‐field‐cooled and field‐cooled magnetization measurements reveal elevated blocking (T _b ) and irreversibility (T _irr ) temperatures, further confirmed by thermoremanent magnetization, with T _b rising from 245.9 K in pristine NPs to 336.8 K in aryl‐functionalized‐CoFe ₂ O ₄ NPs. Molecular‐level modeling further supports the origin of ferromagnetism in aryl‐functionalized‐CoFe ₂ O ₄ NPs. Chemical functionalization of magnetic nanoparticles offers a versatile strategy to tune the magnetic properties of pristine nanoparticles for applications in spintronics, spin‐based memory, and spin logic.

Molecular functionalization of magnetic oxide nanoparticles presents a powerful strategy for interfacial engineering, enabling the emergence of exotic magnetic phenomena. While non‐covalent approaches have been widely explored, they often fail to provide robust interfaces for real applications. We report here covalent surface modification of cobalt ferrite (CoFe ₂ O ₄ ) nanoparticles (NPs) using a series of judiciously selected aryl diazonium salts to achieve a higher degree of surface functionalization and strong interfacial electronic coupling. This modification establishes robust carbon–metal (C–M) covalent bonds at the nanoparticle–molecule interface, conferring chemical stability and tunable magnetic properties. Notably, π‐electron‐rich aryl compounds transform pristine superparamagnetic CoFe ₂ O ₄ NPs into room‐temperature ferromagnets, with a significant increase in coercivity, remanent magnetization, and saturation magnetization, attributed to enhanced surface spin ordering on different sublattices and elevated effective anisotropy. Zero‐field‐cooled and field‐cooled magnetization measurements reveal elevated blocking (T _b ) and irreversibility (T _irr ) temperatures, further confirmed by thermoremanent magnetization, with T _b rising from 245.9 K in pristine NPs to 336.8 K in aryl‐functionalized‐CoFe ₂ O ₄ NPs. Molecular‐level modeling further supports the origin of ferromagnetism in aryl‐functionalized‐CoFe ₂ O ₄ NPs. Chemical functionalization of magnetic nanoparticles offers a versatile strategy to tune the magnetic properties of pristine nanoparticles for applications in spintronics, spin‐based memory, and spin logic.

Chiral nanomaterials exhibit unique optical properties and are used for electronics and sensing applications. Chiral molecules can induce chirality in achiral semiconducting nanomaterials, which can be exploited for the discrimination of chirality. There are different approaches by which achiral metal oxides can be converted into chiral ones; however, a chemical approach to creating a chiral heterostructure is considered more promising for sensing applications. In this work, chiral inducers is utilized such as L‐ and D‐penicillamine (Pen) for preparing chiral L‐Pen‐MoO ₃ ₋ _x and D‐Pen‐MoO ₃ ₋ _x . The induced‐chiral oxide materials display reasonably good anisotropic factors ( g ‐factor, 3 × 10 ^{− 3} ), ensuring chirality is transferred into achiral MoO ₃ . Spectroscopic characterization, morphological, and elemental analyses ensure the formation of L‐Pen‐MoO ₃ ₋ _x or D‐Pen‐MoO ₃ ₋ _x . Induced‐chiral nanomaterials are exploited in two‐terminal electronic devices, exhibiting asymmetric electrical (current‐voltage) response. The chiral heterostructures are further employed for enantioselective sensing of L‐tryptophan and D‐tryptophan probed via differential pulse voltammetry. Quantum mechanical calculations reveal that chiral‐modified electrodes exhibit binding energy values 1–1.3 eV for similar enantiomers, and the values drop to ≈0.5–0.7 eV for dissimilar isomers. This chemical surface‐modification strategy not only introduces chirality transferred in achiral objects but also broadens the functional scope of the heterostructures, enabling enantioselective sensing and chiral electronic applications.