The magic of nano-based materials as catalysts has emerged as a valuable alternative in organic transformations. Recent innovations in nanocatalysis enable chemists to prepare various functionalized nanocatalysts containing metal–organic frameworks (MOFs), zeolites, graphene oxides, and different mixed metal oxides. These catalysts enhance or influence the outcome of chemical reactions compared to conventional catalytic systems. This review highlights recent advancements in nano-based catalysts and summarizes their catalytic potential in the synthesis of pharmaceutically active heterocyclic scaffolds. Furthermore, the role of supported ionic liquid nanocatalysts under environmentally benign reaction conditions is also emphasized. Lastly, the author’s perspectives are briefly discussed, including future developments in the field of nanocatalysis for eco-friendly organic transformations.
The promoting effect of bimetallic sites in metal–organic frameworks (MOFs) provides a promising yet underexplored approach for improving photo-Fenton catalytic efficiency. Herein, a series of cerium-doped NH2-MIL-101(Fe,Ce) catalysts were synthesized via a facile solvothermal method. By adjusting the cerium doping ratio, the optimal NH2-MIL-101(Fe,Ce10
In this study, copper oxide nanoparticles (CuO nanoparticles) were synthesized using an aqueous extract of Glycyrrhiza glabra (Licorice) as a natural reducing and stabilizing agent. The synthesized CuO/Gly nanoparticles were thoroughly characterized using UV–Vis spectroscopy, FT-IR, XRD, FE-SEM–EDS, BET, and TGA analyses. The CuO/Gly nanoparticles exhibited a mesoporous structure, spherical morphology, and good thermal stability. The CuO/Gly nanoparticles were applied as an efficient heterogeneous catalyst for the synthesis of substituted 1,2,3-triazoles under mild and environmentally benign conditions. The catalytic system demonstrated high efficiency, operational simplicity, low cost, and good recyclability. In addition, the antioxidant activity of the CuO/Gly nanoparticles was evaluated using the DPPH radical scavenging assay. The nanoparticles exhibited moderate free-radical- scavenging activity, indicating potential applications beyond catalysis. Overall, this study presents a sustainable and cost-effective strategy for the synthesis of biologically relevant triazole derivatives using a green nanocatalyst.
This study presents the design and fabrication of a molecularly imprinted polymer–semiconductor hybrid photocatalyst, utilizing self-cross-linked 4,4′-methylenedianiline (MDA) integrated with n-TiO2-P25 nanoparticles, for visible-light-driven oxidation of benzyl alcohol. Both molecularly imprinted (MIPPMDA/n-TiO2-P25) and non-imprinted (NIPPMDA/n-TiO2-P25) composites were synthesized and systematically characterized using FT-IR, XRD, FE-SEM, BET, diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) analyses. These analyses confirmed the formation of hybrid structures with favorable optical and surface properties. DRS and PL results suggest that incorporation of 4,4′-methylenedianiline (PMDA) into the n-TiO2-P25 system extends the visible-light response and may reduce charge-carrier recombination. Furthermore, molecular imprinting introduced preferential recognition sites, which may enhance the adsorption affinity and photocatalytic selectivity toward benzyl alcohol compared with the non-imprinted counterpart. Under blue LED irradiation and natural sunlight, the MIP composite demonstrated superior photocatalytic performance for benzyl alcohol oxidation, achieving up to 91
In this study, lignin, as a green and readily available phytochemical, was used to coat Fe3O4 nanoparticles, followed by the immobilization of a Brønsted acidic ionic liquid onto the resulting surface to form Fe3O4@Lignin-IL-SO3H. The synthesized magnetic nanocatalyst was identified and investigated by different analyses such as XRD, FT-IR, FE-SEM, VSM, TEM, EDX, and TGA techniques. Fe3O4@Lignin-IL-SO3H was employed as a highly efficient and recyclable heterogeneous catalyst for the synthesis of indeno-1,2,4-triazolo[1,5-a]pyrimidine derivatives, a valuable class of nitrogen-containing heterocyclic compounds, via a three-component reaction of aldehydes, indan-1,3-dione, and 3-amino-1H-1,2,4-triazole under mild reaction conditions. The optimal reaction conditions were achieved using 0.008 g of catalyst under solvent-free conditions at 50 °C, affording the desired products in 80–96
Heterojunctions have garnered significant interest in photocatalysis due to their capacity to facilitate efficient charge separation and improved interfacial interaction. In this area, designing interfaces composed of nanostructured two-dimensional/one-dimensional (2D/1D) materials remains an excellent way to boost light absorption and tune band structure. The photocatalytic performance of traditional semiconductor systems is constrained by rapid charge carrier recombination, insufficient surface-active sites, and limited utilization of incident light. In this context, nano-architectonics, which integrates nanoscale structural design with controlled interfacial engineering, has emerged as an effective strategy for constructing advanced mixed-dimensional photocatalysts with improved charge transport pathways and enlarged reactive surfaces. Herein, a hetero-structured 2D/1D g-C3N4/MnO2 nanocomposite was successfully fabricated by embedding nanorods within nanosheets. The synthesized mixed nanocomposite was systematically characterized to evaluate its morphology, structural properties, optical behaviour, and chemical composition. Owing to the synergistic effects arising from the designed nano-architectonics, this heterostructure demonstrated significant results in terms of hydrogen generation (up to 4310 μmol g−1 h−1) through water splitting as well as the degradation of methylene blue (MB) dye (97.69
In this study, the effects of iron/activated carbon (Fe/AC) catalysts modified with iridium (Ir), cobalt (Co), and cerium (Ce) on the NO removal performance through the coupled CO + NH3 process at medium and low temperatures were investigated. Then, 1.0Ir, Co, and Ce-12.5Fe/AC catalysts were prepared, and the reaction pathway for the coupled NO removal process was proposed based on ex situ characterization results and previously reported catalytic mechanisms. The results showed that, when compared at the same reaction temperature, the 1.0Co-12.5Fe/AC catalyst exhibited the highest NO removal activity in the coupled CO + NH3 process. The 1.0Ir-12.5Fe/AC and the 1.0Ce-12.5Fe/AC catalysts exhibited the highest NO removal activity at the medium-temperature stage and the high-temperature stage, respectively. The subsequent loading of the second metal partially blocked the catalyst pores, thus reducing the specific surface area to varying degrees. The bimetallic loading intensified the catalyst γ-Fe2O3 diffraction peaks, increased the crystallinity, and deteriorated the dispersion. Additionally, it significantly increased the proportion of Fe2+, and the redox reactions occurred between Ir and Fe, Co and Fe, and Ce and Fe. The Oβ content after the second metal loading was significantly higher than that of the single-metal loading, thereby improving the NO removal activity of the catalysts.
This work presents the synthesis and application of uracil-modified hyper-cross-linked polymers (UHCP-Fe and UHCP-Al) as high-performance adsorbents for phenol removal from aqueous solutions. The materials were fabricated via a two-step procedure involving initial grafting of uracil onto chloromethylated polystyrene, followed by a Friedel–Crafts reaction to form the hyper-cross-linked network. Structural analyses confirmed the successful incorporation of uracil and the formation of hierarchical porous architectures, with SBET values reaching 352.2 m2/g for UHCP-Fe and 122.9 m2/g for UHCP-Al. The adsorbents demonstrated exceptional phenol adsorption capacities of 146.8 and 133.1 mg/g at 298 K, respectively, attributed to synergistic interactions such as hydrogen bonding, micropore filling, acid-base interactions, and π–π stacking. Adsorption kinetics were best described by a pseudo-second-order model, while equilibrium data were well-fitted to both Langmuir and Freundlich isotherms, with the Langmuir model showing higher correlation coefficients for UHCP-Fe and UHCP-Al. Thermodynamic studies indicated the process was exothermic, with optimal removal ( 91.4
A sustainable, one-pot, multicomponent protocol has been developed for the synthesis of 2,3-diphenyl-1,3-thiazolidin-4-one using p-aminobenzoic acid (PABA) as an inexpensive, eco-friendly, and recyclable organocatalyst. A straightforward and environmentally friendly route to biologically significant heterocyclic scaffolds was provided by the solvent-free reaction of aromatic aldehydes, substituted anilines, and thioglycolic acid. The developed methodology demonstrated a broad substrate range and impressive tolerance to electron-donating, electron-withdrawing, halogenated, nitro-substituted, and heteroaromatic aldehydes, as well as to substituted aniline derivatives, yielding good yields of desired products. The structures of the synthesized compounds were confirmed by 1H and 13C NMR spectroscopy, demonstrating the successful synthesis of the target heterocycles. The PABA catalyst was readily recyclable and reusable in five consecutive cycles, with only a slight decrease in catalytic activity, demonstrating the protocol’s viability and sustainability.
The development of multifunctional heterocyclic hybrid frameworks has emerged as a promising strategy for discovering new therapeutic agents with enhanced biological profiles. Here, we report the synthesis of novel coumarin-benzimidazole hybrid molecules 6a-o using an efficient Sonogashira cross-coupling approach catalyzed by a Pd(0)/CuI catalytic system. The bimetallic system efficiently facilitated C(sp2)–C(sp) bond formation under mild reaction conditions, affording desired derivatives in higher yields up to 88
Palladium-based membranes are widely recognised for their excellent hydrogen selectivity and permeability at elevated temperatures, making them promising candidates for hydrogen purification and membrane reactor applications. In this study, Pd composite membranes were fabricated on porous α-Al2O3 tubular supports using Pd-doped SBA-15 as an intermediate layer to enhance membrane quality and reduce the Pd selective layer thickness. SBA-15 was synthesised via three different routes: sol–gel, precipitation, and hydrothermal methods, followed by Pd doping to create nucleation sites for Pd film growth. The intermediate layers were deposited on the ceramic supports using vacuum-assisted dip coating, and the Pd selective layer was formed by the electroless pore-plating method. The structural and morphological properties of SBA-15 and Pd-SBA-15 were characterised using XRD, BET surface area analysis, TEM, and SEM. The results confirmed the preservation of the ordered mesoporous SBA-15 structure after Pd incorporation and the formation of a continuous and defect-free Pd selective layer. Hydrogen permeation experiments were conducted between 300 and 400 °C under different pressure conditions. Hydrogen flux showed a linear dependence on the square root pressure difference, confirming Sieverts’ law and the solution–diffusion mechanism. Among the membranes studied, the hydrothermally synthesised Pd-SBA-15 support exhibited the highest hydrogen flux and the lowest activation energy (13.60 kJ mol−1), indicating improved hydrogen transport and reduced mass transfer resistance.
The valorization of petroleum waste into high-performance catalytic materials is a major frontier of sustainable chemistry. This paper reports the preparation of a robust, highly active asphaltene oxide (AO) solid-acid catalyst via controlled oxidation with nitric acid. In contrast to the destructive Hummers approach, which results in a disastrous loss of carbon (16.58
Sensitive and rapid determination of ascorbic acid (AA) is essential for clinical diagnostics, oxidative stress assessment, and food quality monitoring. Herein, a novel synergistic SrO/MnO2 nanozyme with oxygen vacancies and mixed valences of manganese for fast and colorimetric detection of AA is reported without using any chemical agents and without using chromogenic substrate or oxidant in the assay procedure. In contrast with the current nanozyme-based assays, which depend on the use of chromogenic substrates and oxidants for AA sensing, this proposed sensing strategy is based on the natural redox reaction of AA with the nanozyme SrO/MnO2, allowing direct detection of AA without using 3,3ʹ,5,5ʹ-tetramethylbenzidine (TMB) or hydrogen peroxide (H2O2). Under optimum conditions, the developed nanozyme offered an extensive linear dynamic range from 1 to 100 µM, a low limit of detection of 0.77 µM, a low limit of quantitation of 2.5 µM, and the whole test took just 2 min. Besides, the developed sensor proved to be highly selective toward AA, exhibiting good discrimination between AA and other potentially interfering biomolecules and inorganic ions. Moreover, the SrO/MnO2 nanozyme possessed high catalytic stability under various pHs and temperatures and could be used multiple times, pointing to its high stability and cost-effectiveness as opposed to enzymatic sensors. Practical applicability of the designed sensing system was confirmed through successful detection of AA in human serum, commercial vitamin C tablets, and beverages with no negative matrix effects. These results clearly indicate that the heterostructure SrO/MnO2 nanozyme can form a fast, sensitive, and eco-friendly TMB- and H2O2-free colorimetric sensor, having great potential in clinical, food safety, and point-of-care testing of antioxidants. Graphical representation of ascorbic acid detection without the use of enzymes or any other material.
In this study, chlorogenic acid was isolated from ethanolic extract of Hymenocrater bituminosus using a preparative high-performance chromatography. Then, a bio-inspired Ni(II)-CGA complex was synthesized using a simple and environmentally friendly process, and its structural and morphological properties were extensively characterized. The Ni(II)-CGA was analyzed using FTIR, confirming the formation of coordination between Ni(II) and the phenolic groups of CGA because the stretching vibration of CGA carbonyl groups were shifted to the lower wavenumbers following the metal–phenol interactions. XRD pattern confirms the formation of coordinated bonds between Ni(II) and oxygen atoms of CGA. SEM and TEM images confirm the formation of grain-like aggregated nanoparticles with sizes ranging from 15 to 40 nm, in which Ni(II) cores with sizes less than 5 nm are distributed in a non-crystalline and amorphous organic matrix of CGA. The catalytic activity of the Ni(II)-CGA nanoparticles was investigated in the Heck coupling reaction under mild conditions. Systematic optimization revealed that 4 mol
Developing low-cost and high-performance catalysts is essential for practical hydrogen generation from chemical hydrides. In this study, a magnesium–aluminum layered double hydroxide catalyst was successfully prepared through a urea-assisted hydrothermal co-precipitation route and applied for hydrogen production via sodium borohydride methanolysis. Structural analyses confirmed the formation of a crystalline layered framework with homogeneously dispersed nano-sized particles and a porous surface architecture. Under the selected reaction conditions (0.125 g NaBH4, 10 mL methanol, 0.01 g Mg–Al LDH catalyst, and 30 °C), the catalyst achieved a hydrogen generation rate (HGR) of 18,674 mL min⁻1 g⁻1 and the catalyst generated 330 mL of hydrogen within 4.5 min, indicating rapid catalytic kinetics. The enhanced activity was associated with the cooperative interaction between magnesium and aluminum active centers, which promoted surface basicity and accelerated borohydride activation. Furthermore, the catalyst preserved its structural integrity and catalytic efficiency during five consecutive reuse cycles with only minor performance loss. These findings demonstrate that magnesium–aluminum layered double hydroxide is a promising catalyst for efficient and sustainable on-demand hydrogen production in future portable clean energy conversion and storage systems.
In the present study, Zn-doped Co3O4 nanoparticles were synthesized through an environmentally friendly green route using Catharanthus roseus leaves extract. The leaf extract served as both a bio-reducing and stabilizing agent, eliminating the need for toxic chemicals and harsh reaction conditions. The phytochemical constituents facilitated the controlled formation of nanoscale particles. The synthesized nanoparticles were thoroughly characterized using XRD, SEM, EDS, IR spectroscopy and BET surface area analysis to evaluate their structural, morphological, compositional, surface and textural properties. Their catalytic performance was investigated in the synthesis of benzimidazole derivatives through the condensation of o-phenylenediamine with various aldehydes under mild reaction conditions. The catalyst exhibited excellent activity, affording high yields (90–97
Semiconductor photocatalysis offers an environmentally sustainable approach for the elimination of organic contaminants from wastewater. However, the photocatalytic performance of Zn2In2S5 (ZIS) is often limited by nanosheet aggregation, insufficient exposure of active sites, and the incomplete understanding of reactive oxygen species (ROS) evolution. In this study, marigold-like ZIS microspheres with a 2D-3D hierarchical porous structure were fabricated, and their performance in the photocatalytic degradation of rhodamine B (RhB) was investigated. The structural and physicochemical properties of the obtained ZIS were systematically investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectroscopy (DRS), and Mott–Schottky analysis. The results demonstrated that this unique structure integrates the advantages of the short charge migration distance of 2D materials and multiple light scattering/adsorption sites of 3D structures. Under AM 1.5 simulated sunlight irradiation, the as-prepared ZIS photocatalyst exhibited excellent photocatalytic activity, with a RhB degradation efficiency of up to 99.7
The preparation of biologically active compounds, such as enaminones, has been continuously scrutinized in the search for the best catalyst to make the process greener, more efficient, and more sustainable. The present article discloses the fabrication of a bimetallic Pd-Cu-anchored cellulose-supported metal–organic framework i.e. RH-CNC@NH2-BDC-Fe@Pd-Cu, where RH-CNC was derived from agrowaste rice husk. The formation of the catalyst was confirmed by various physicochemical characterizations using FTIR, Raman, FESEM, EDX, XRD, XPS, BET, and TGA, which indicate successful immobilization, structural integrity, and magnetic recoverability. The fabricated catalyst was used to synthesize enaminone derivatives from dimedone via a sequential one-pot Heck coupling reaction. The enaminone product 5a was further explored for the synthesis of a bioactive azepinone framework. To assess the catalyst efficacy, the reaction was studied with a series of substrates, yielding excellent yields and remarkable catalytic cycles.
The bio-inspired nitrogen-doped carbon quantum dots (N-CQDs) were synthesized through one-step hydrothermal conversion of Moringa oleifera seed husk. In this process, the seed husk serves as a carbon and nitrogen precursor. The EDX analysis of N-CQDs displaying a broad (002) diffraction band and weak (100) reflection confirms its quasi-graphitic nanostructure. The TEM analysis reveals the uniform dispersion of particles with an average diameter of 4.9 nm. The FT-IR and XPS analyses confirm the presence of abundant oxygen- and nitrogen-rich surface functional groups. Systematic optimization reveals that neutral pH (7), an adsorbent dose of 0.5 g/L, agitation at 150 rpm, and an initial analyte concentration of 100 μg/mL display the most efficient adsorption performance. In these optimized conditions, N-CQDs achieve high pollutant removal (> 90
