Solar-activated and hydrothermally synthesized effective rGO/Ag2S composites for the destruction of naphthol green B dye and antibacterial applications.

Graphene-based nanocomposites are developing as a new class of materials with several uses. The varied weight percentages of rGO on Ag2S catalysts were synthesized using a simple hydrothermal process and employed for the decomposition of anionic dye naphthol green B (NGB) under solar light. The reduced graphene oxide-based silver sulfide (rGO/Ag2S) nanoparticles were then examined using XRD, SEM, EDS, HR-TEM, XPS, UV-DRS, and PL analysis. Using solar light, the photocatalytic activity of the produced catalyst was examined for the degradation of naphthol green B (NGB) in an aqueous solution. At pH 9, rGO/Ag2S is discovered to be more effective than the other catalysts for the NGB dye mineralization. Analyses have been conducted on the influence of operational parameters on the photo-mineralization of NGB, including the initial pH, initial dye concentration, and catalyst dosage. The dye concentration increased; the efficiency of photocatalytic degradation tended to decrease. Chemical oxygen demand (COD) studies have verified the NGB dye mineralization. Active species trapping revealed that holes, hydroxyl radicals, and superoxide radicals all played major roles in the photocatalytic deterioration of NGB processes. Additionally, a potential mechanism of NGB dye degradation by rGO/Ag2S catalyst is presented. The synthesized compound was further evaluated for antibacterial activity, and the results indicated that rGO/Ag2S were potentially effective antibacterial agents.

Rational construction of MOF derived α-Fe2O3/g-C3N4 composite for effective photocatalytic degradation of organic pollutants and electrocatalytic oxygen evolution reaction.

In recent years, researchers have been actively investigating metal oxide-based materials with narrow bandgaps due to their potential applications toward wastewater treatment and oxygen evolution reactions (OER). In this study, we successfully synthesized g-C3N4 (GCN), Fe2O3, and Fe2O3/g-C3N4 (FGCN) using thermal polymerization and hydrothermal methods. We characterized the physicochemical and structural properties of these materials through various analytical techniques including XRD, FT-IR, UV-DRS, XPS, FE-SEM, and HR-TEM analyses, confirming the effective construction of the FGCN composite catalyst. We evaluated the photocatalytic activity of Fe2O3, GCN, and FGCN composite catalysts by assessing their ability to degrade rhodamine B (RhB) and crystal violet (CV) by exposing them to sunlight for 150 min. Among these catalysts, the FGCN composite demonstrated excellent photocatalytic performance, achieving 93 % and 95 % degradation of RhB and CV, respectively, under 150 min of sunlight exposure. The developed Fe2O3/g-C3N4@Nickel foam (FGCN@NF) composite catalyst exhibits remarkable OER performance, with a reduced Tafel slope of 64 mV/dec and a low overpotential of 290 mV at a current density of 10 mA/cm2 and shows excellent durable performance over a long time (15 h). Total Organic Carbon (TOC) analysis confirmed the mineralization of both dyes. The photocatalytic performance remained largely unchanged after five consecutive experiments, demonstrating excellent reusability and photostability. Trapping experiments revealed that O2●- is the main species responsible for the photocatalytic decomposition of various dyes by the FGCN composite catalyst. Therefore, the development of a versatile photo/electrocatalytic system that can efficiently promote energy conversion in environmental applications has attracted great attention.

Fabrication of Bi2O3/Bismuth Titanates Modified with Metal-Organic Framework-In2S3/CdIn2S4 Materials for Electrocatalytic H2 Production and Its Photoactivity.

Compositional and structural elucidation of the materials is important to know their properties, chemical stability, and electro-photoactivity. The heterojunction electrocatalyst and photocatalyst activity could open a new window for solving the most urgent environmental and energy problems. Here, for the first time, we have designed and fabricated Bi2O3/bismuth titanates modified with MOF-In2S3/CdIn2S4 materials by a stepwise process. The detailed structural elucidation and formation of mixed composite phases were studied in detail. It has been found that the formed composite was efficiently utilized for the electrocatalytic H2 production reaction and the photocatalytic degradation of tetracycline. XRD patterns for the metal-organic framework-In2S3 showed a main compound of MOF, and it was assigned to a MIL-53 MOF phase, with a monoclinic structure. The addition of CdCl2 onto the MOF-In2S3 phase effectively produced a CdIn2S4 flower platform on the MOF rods. The uniform dispersion of the bismuth titanates in MOF-In2S3/CdIn2S4 materials is detected by mapping of elements obtained by dark-field HAADF-STEM. Finally, the predictions of how to integrate experiments and obtain structural results more effectively and their common development in new heterojunctions for electro-/photocatalytic applications are presented.

Highly Efficient Solar-Light-Active Ag-Decorated g-C3N4 Composite Photocatalysts for the Degradation of Methyl Orange Dye.

In this study, we utilized calcination and simple impregnation methods to successfully fabricate bare g-C3N4 (GCN) and x% Ag/g-C3N4 (x% AgGCN) composite photocatalysts with various weight percentages (x = 1, 3, 5, and 7 wt.%). The synthesized bare and composite photocatalysts were analyzed to illustrate their phase formation, functional group, morphology, and optical properties utilizing XRD, FT-IR, UV-Vis DRS, PL, FE-SEM, and the EDS. The photodegradation rate of MO under solar light irradiation was measured, and the 5% AgGCN composite photocatalyst showed higher photocatalytic activity (99%), which is very high compared to other bare and composite photocatalysts. The MO dye degradation rate constant with the 5% AgGCN photocatalyst exhibits 14.83 times better photocatalytic activity compared to the bare GCN catalyst. This photocatalyst showed good efficiency in the degradation of MO dye and demonstrated cycling stability even in the 5th successive photocatalytic reaction cycle. The higher photocatalytic activity of the 5% AgGCN composite catalyst for the degradation of MO dye is due to the interaction of Ag with GCN and the localized surface plasmon resonance (SPR) effect of Ag. The scavenger study results indicate that O2●- radicals play a major role in MO dye degradation. A possible charge-transfer mechanism is proposed to explain the solar-light-driven photocatalyst of GCN.

Layered KTO/BiOCl nanostructures for the efficient visible light photocatalytic degradation of harmful dyes.

Novel KTO/BiOCl nanostructured photocatalysts with various weight proportions were synthesized using a simple hydrothermal process. The as-prepared nanostructured composite catalysts were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, UV-vis diffused reflectance spectroscopy, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy with high resolution, X-ray photoelectron spectroscopy, and photoluminescence (PL). The photocatalytic activity of prepared catalysts was examined using Rhodamine B (RhB) and Congo Red (CR) as the aimed pollutants. BiOCl nanoparticles were distributed uniformly on the surface of the K2Ti4O9 nanobelts. The optical properties showed that the layered titanate with BiOCl nanostructured photocatalyst displayed improved photoresponsivity due to the narrowed bandgap. The PL results showed that the greater inhibition of the electron-hole recombination process and KTO/BiOCl with a mass proportion of 20% revealed the most favorable photocatalytic behavior. The rate constant of RhB and CR degradation was five times as high as that of the bare BiOCl and titanate. The superior photocatalytic performance was attributed to the advancement of heterojunction between the KTO nanobelt and BiOCl. The KTO/BiOCl nanostructure is a promising visible, active photocatalyst, and the photocatalytic mechanism is discussed using the possible band structures of BiOCl and KTO.

Facile hydrothermal synthesis of manganese sulfide nanoelectrocatalyst for high sensitive detection of Bisphenol A in food and eco-samples.

Bisphenol A (BPA) is a renowned plasticizer, and a key component of various plastics, resins, and food packaging materials. However, BPA have been identified as an endocrine disruption compound and cause severe consequences such as infertility, diabetic, obesity, carcinoma, and possess high risk of exposure in aquatic ecosystem. To this, we crafted an ultrasensitive electrochemical sensor based on the manganese sulfide nanoparticles (MnS NPs) catalyzed electrochemical oxidation of BPA, and its eventual application in rapid screening of BPA contamination. The physiochemical characteristics and electrocatalytic performance of the MnS nanocatalyst have been well studied and utilized in the fabrication of MnS/GCE based BPA sensor. The fabricated BPA sensor has shown a broad dynamic range (20 nM-2.15 mM), lower detection limits (6.52 nM) and promising towards rapid screening of BPA contaminations in food and environmental samples under mimicked real-world conditions with excellent accuracy and precision.

Development of a novel latent electrochemical molecular substrate for the real-time monitoring of the tumor marker aminopeptidase N in live cells, whole blood and urine.

Aminopeptidase N (APN/CD13) plays an important role in the growth and metastasis, of tumor, and is a potential biomarker for the post-treatment surveillance of cancer reoccurrence and progression of various malignancies. Thus, we have designed and prepared a convenient and ultrasensitive APN-targeting activity-based ratiometric electrochemical molecular substrate (Ala-AFC) for direct real-time monitoring of APN activity in biosamples. The APN in our experiment was used to hydrolyze the alanine moiety of the Ala-AFC probe and, as a result of this hydrolysis, realize concomitantly a cascade reaction to unmask the electrochemical reporter N-alkylated amino ferrocene (AAF). The Ala-AFC probe exhibited high sensitivity with a wide detection range of 0.05-110 ng mL-1 and a low limit of detection of 23.18 pg mL-1. The electrochemical signals were found to be distinctly specific for APN and free of interference from other electroactive biological species. Furthermore, the Ala-AFC probe was employed to monitor and quantify, in real-time, the activity of APN in tumor cells, whole blood, and urine. In addition, the results of our direct electrochemical quantifications of the amount of APN in whole blood and urine were found to be consistent with the results of the use of commercially available fluorometric assay kits to sense APN in serum and urine. Thus our approach shows promise as a point-of-care tool for cancer diagnostics and post-treatment surveillance of cancer reoccurrence.

Convenient and ultrasensitive detection of live Salmonella using ratiometric electrochemical molecular substrates.

Salmonella contamination is a major concern in food and public health safety, and carrying out episodic monitoring of Salmonella contamination in food and water bodies is essential for safeguarding public health and the economy. Therefore, there is an urgent need to develop an easy-to-operate Salmonella-targeting point-of-care detection platform. To this end, we designed two activity-based latent ratiometric electrochemical molecular substrates, denoted as Sal-CAF and Sal-NBAF, specifically for achieving easy, rapid, and selective profiling of Salmonella esterase (a Salmonella biomarker) under physiological conditions. The octyl esters of the substrates were cleaved by the esterase and triggered the trimethyl lock to eject the electron-rich aminoferrocene derivatives (CAF and NBAF), and the corresponding electrochemical signals were tracked at the negative region (-0.08 V vs Ag/AgCl) of the voltammetric spectrum. The Sal-CAF substrate was used to determine the concentration of Salmonella in a wide dynamic range (1.03 × 105-1.1 × 1010 CFU mL-1) with a low detection limit of 39.27 × 103 CFU mL-1. The developed probes were tested against various bacteria but were only activated by live Salmonella. Furthermore, the Sal-CAF probe was used directly in quantifying spiked live Salmonella spiked in milk samples and also used to effectively monitor and quantify Salmonella production in real-time. These achievements indicated the Sal-CAF probe to be a promising platform for point-of-care Salmonella analysis.

Ru/TiO2 Nanostructured Catalysts: Synthesis, Characterization and Catalytic Activity Towards Hydrogenation of Ethyl Levulinate.

Pristine TiO2 and x% Ru/TiO2 catalysts with different wt.% of Ru (x%= 1.5%, 2%, 2.5% and 3%) were synthesized using sol-gel and simple impregnation methods. Different characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), High-resolution transmission electron microscope (HR-TEM), Inductively coupled plasma-optical emission spectrometry (ICP-OES) and Thermogravimetry/Differential thermal analysis (TG/DTA) were used to study the physicochemical and morphological properties. The XRD patterns of the as-prepared pristine TiO2 catalyst showed high crystalline nature. The HR-TEM images revealed that the Ru nanoparticles (NPs) were evenly dispersed on the TiO2 surface. The prepared catalysts were evaluated for their catalytic activity towards the liquid phase hydrogenation of ethyl levulinate under mild reaction conditions (ambient H2 pressure). Among the various catalysts, 2.5% Ru/TiO2 catalyst showed the maximum catalytic activity of 79% ethyl levulinate (EL) conversion with 82% selectivity of γ-valerolactone (GVL). The recyclability test revealed that the most active 2.5% Ru/TiO2 also showed the highest stability of the catalyst under optimized experimental conditions.

Degradation of Harmful Organics Using Visible Light Driven N-TiO2/rGO Nanocomposite.

Nitrogen doped titania over reduced form of graphene oxide (N-TiO2/rGO) catalysts were synthesized by adopting single step hydrothermal route. All the prepared photocatalysts were thoroughly characterized by using different analytical tools such as XRD, Raman, UV-DRS, FE-SEM and HRTEM. The photocatalytic activities of bare and composite catalysts were evaluated towards the photocatalytic decolourisation/degradation of Methylene blue dye (MB) and Metronidazole antibiotic (MTZ) under visible electromagnetic radiation. Among all the synthesized catalysts, N-TiO2/rGO composite catalyst showed the highest decolourisation/degradation activity towards both the dye and the antibiotic. The most active catalyst was also tested under UV and solar light irradiations which showed promising results. The stability of the most active catalyst (N-TiO2/rGO) was examined by recyclability test. The possible photocatalytic mechanism was proposed for the composite catalyst.

3D Flower-like NiCo Layered Double Hydroxides: An Efficient Electrocatalyst for Non-Enzymatic Electrochemical Biosensing of Hydrogen Peroxide in Live Cells and Glucose in Biofluids.

Herein, a hierarchical structure of flower-like NiCo layered double hydroxides (NiCo LDH) microspheres composed of three-dimensional (3D) ultrathin nanosheets was successfully synthesized via a facile hydrothermal approach. The formation of NiCo LDH was confirmed by various physicochemical studies, and the NiCo LDH-modified glassy carbon electrode was used as an efficient dual-functional electrocatalyst for non-enzymatic glucose and hydrogen peroxide (H2O2) biosensor. The host matrix of hydrotalcite NiCo LDH exhibits the enhanced electrocatalytic sensing performances with a quick response time (<3 s), wide linear range (50 nM-18.95 mM and 20 nM-11.5 mM) and lowest detection limits (S/N = 3) (10.6 and 4.4 nM) toward glucose and H2O2, and also it exhibits good stability, selectivity, and reproducibility. In addition, this biosensor was successfully utilized to the real-time detection of endogenous H2O2 produced from live cells and glucose in various biological fluids, and demonstrates that the as synthesized NiCo LDH may provide a successful pathway for physiological and clinical pathological diagnosis.

Development of ratiometric electrochemical molecular switches to assay endogenous formaldehyde in live cells, whole blood and creatinine in saliva.

Formaldehyde is a reactive carbonyl species (RCS) that is produced naturally in the human body via metabolic and epigenetic biochemical processes, yet in high concentrations is highly toxic to the environment as well as to living organisms. Therefore, we designed two ratiometric electrochemical molecular redox probes, Formaldehyde oxidative latent probe (FOLP) and dihydroxy-formaldehyde oxidative latent probe (HFOLP), for the selective profiling of endogenous formaldehyde. FOLP and HFOLP each underwent the aza-Cope reaction with formaldehyde followed by hydrolysis to eliminate unmask redox reporter N-alkylated aminoferrocene (AAF) to monitor their response current. The FOLP and HFOLP sensors showed broad dynamic ranges of 0.12-1000 µM and 0.09-3 mM for formaldehyde with detection limits of 48.2 nM and 31.6 µM, respectively. Also, since formaldehyde is the byproduct of biochemical reactions for detecting creatinine and creatinine is an important biomarker for chronic kidney disease (CKD), we tested the FOLP probe for its ability to monitor creatinine. It successfully did so, and this ability was used to develop an electrochemical platform for the quantification of creatinine; it showed a dynamic range of 3.25-200 µM and a limit of detection (1.3 µM). In addition, the FOLP-based assay platform delivered a reliable analytical performance for the quantification of formaldehyde in human whole blood and of creatinine in saliva, and also for the real-time monitoring of endogenous formaldehyde secretion in HeLa cells. Moreover, the concentrations determined using our method were found to be consistent with those determined using formaldehyde and creatinine fluorometric assay kits.

FeMn layered double hydroxides: an efficient bifunctional electrocatalyst for real-time tracking of cysteine in whole blood and dopamine in biological samples.

A peculiar clock-regulated design of FeMn-LDHs (FMH) with specific physiochemical attributes has been developed and used for highly sensitive detection of cysteine (CySH) and dopamine (DA). The FMH nanoparticles were synthesized via a facile hydrothermal approach clocked at various (6 h, 12 h and 18 h) operating periods. Under optimal conditions, FMH were obtained in three unique morphologies such as hexagonal plate like, cubic, and spherical structures corresponding to the clocked periods of 6 h, 12 h, and 18 h, respectively. Among these, FMH-12 h possess the minimal particle size (54.45 nm), a large surface area (7.60 m2 g-1) and the highest pore diameter (d = 4.614 nm). In addition to these superior physiochemical attributes, the FMH nanocubes exhibit excellent electrochemical behaviors with the lowest charge transfer resistance (Rct; 96 Ω), a high heterogeneous rate constant (7.81 × 10-6 cm s-1) and a good electroactive surface area (0.3613 cm2), among the three. The electrochemical biosensor based on the FMH nanocubes exhibits a remarkable catalytic activity toward CySH and DA with a low detection limit (9.6 nM and 5.3 nM) and a broad linear range (30 nM-6.67 mM and 20 nM-700 µM). The FMH based biosensor is also feasible for the real-world detection of CySH in whole blood and DA in biological fluids with satisfactory results. The proposed sensor possessed high selectivity, good repeatability, and reproducibility toward CySH and DA sensing.

Ratiometric electrochemical molecular switch for sensing hypochlorous acid: Applicable in food analysis and real-time in-situ monitoring.

A ratiometric electrochemical molecular sensing platform for real-time quantification of extracellular hypochlorous acid (HClO) production has been developed based on a latent electrochemical probe aminoferrocene thiocarbamate (AFTC 3). The substrate AFTC consist of a masked redox reporter amino ferrocene (AF 4) linked with a dimethylthiocarbamate trigger via hydroxyl benzyl alcohol. The conceptual idea behind the probe design is based on a specific chemical interaction between HClO and dimethylthiocarbamate, which allows only HClO to unmask the probe to releases AF. The scheme was manipulated to establish a highly selective (in presence of various reactive oxygen species, anions and other biological interfering species) and sensitive (detection limit 75 nM) sensing platform not only in lab samples but also in real samples (food samples, and live cells). Real-time in situ quantification platform was developed to profile HClO productions in macrophages, and it did so with great consistency.

Electrochemical substrate for active profiling of cellular surface leucine aminopeptidase activity and drug resistance in cancer cells.

Leucine aminopeptidase (LAP) is an essential proteolytic enzyme and potential biomarker for liver malignancy. Overexpression of LAP is directly linked with some fatal physiological and pathological disorders. In this regard, we have designed an activity based electrochemical substrate leucine-benzyl ferrocene carbamate (Leu-FC) for selective profiling of LAP activity in live cells. In practice, LAP instantaneously hydrolyze the Leu residue of the substrate Leu-FC to eliminate the unmasked electrochemical reporter amino ferrocene via predefined self-immolative cascade. The electrochemical signal is distinctly specific for LAP and free of other electroactive biological interference. The substrate Leu-FC empowered sensor displayed broad dynamic range with admirable detection limits. On top of this, the probe Leu-FC was employed in real-time active profiling of cellular LAP activity in HepG2 cells and effect of LAP inhibitor. In extent, the substrate Leu-FC can effectively monitor cisplatin induced overexpression of LAP activity in HepG2 cells in presence and absence of bestatin. The sensor showcased an excellent reliability towards monitoring cellular LAP activity in HepG2 cells. Unlike the traditional antibody-based immunoassays, our approach is capable of monitoring in-situ activity of LAP in live cells.

Liquid Phase Esterification of Levulinic Acid into Ethyl Levulinate Over Sulphobenzylated Nanoporous Al-SBA-15 Catalyst.

Value added chemicals, fuels, and fuel additives can be obtained from cheap bio masses such as levulinic acid. Levulinic acid is the dehydration and hydrolysis products of pentoses and hexoses. The present work deals with the synthesis of sulphobenzylated Al-SBA-15, [SO3H-Bz-Al-SBA-15], characterization by various analytical techniques such as XRD, BET, FT-IR, TGA, DTA, FE-SEM/EDS and HR-TEM/EDX techniques and evaluation of catalytic activity towards esterifi-cation of levulinic acid to ethyl levulinate under mild and non corrosive conditions. Sulphonation of the aromatic ring of the benzyl group has been done in different amounts to get nanoporous x% SO3H-Bz-Al-SBA-15 catalysts where (x ═ 0.02, 0.04, 0.06, 0.08 and 0.10% w/w). Among them 0.08% SO3H-Bz-Al-SBA-15 catalyst showed the highest conversion of levulinic acid (100%) with the highest selectivity towards ethyl levulinate (100%). Esterification of levulinic acid has been carried out with different primary alcohols and all of them yielded 100% selectivity towards alkyl levulinate. However conversion level of levulinic acid was found to be different with different alcohols. Reaction conditions have been optimized. The results were compared with other supported catalysts and discussed.

Facile Synthesis, Characterization and Enhanced Photocatalytic Activities of NiWO4/Nitrogen Doped Reduced Graphene Oxide Nanocomposites.

In this study, we report the synthesis of NiWO4/nitrogen doped reduced graphene oxide nano composite by one-pot hydrothermal method. The NiWO4 nano particles were dispersed uniformly on graphene sheets. The as prepared NiWO4, NiWO4/5% rGO and NiWO4/N-5% rGO composites were analytically characterized by Powder X-ray diffraction (XRD), Raman spectroscopy, Diffuse reflectance spectroscopy (DRS-UV), Scanning electron microscopy (SEM) and N2 adsorption-desorption isotherm. The photocatalytic performances of the synthesized composites were evaluated towards the photo degradation of congo red (CR) under visible light radiation. The synthesized catalysts showed remarkable photocatalytic activity in the degradation of CR. Among the catalysts NiWO4/N-5% rGO showed the highest decolourization of congo red (92%) under visible light irradiation. This high activity is attributed to its high e- transport property. Our results provide an invaluable methodology for designing high-performance photo-catalysts for new energy applications.

Facile synthesis of copper sulfide decorated reduced graphene oxide nanocomposite for high sensitive detection of toxic antibiotic in milk.

The development of an effective technique for detecting antibiotic drugs remains a serious task due to their toxicity to public health. For this purpose, herein, we report an electrochemical detection based on Cu2S nanosphere decorated reduced graphene oxide (RGO@Cu2S NC) nanocomposite. A sonochemical-assisted method was adopted to prepare the nanocomposite. Subsequently, its morphological, elemental, and crystal structural aspects were analysed. The electrochemical properties were examined in order to ensure the material's suitability in electrocatalytic sensing. RGO@Cu2S NC affixed screen-printed electrode was found to exhibit tremendous electrocatalytic capability toward chloramphenicol (CAP) reduction. A sensitive and reproducible amperometric CAP sensor was fabricated which was able to detect concentration at the nanomolar level. The method worked well even in real samples (fresh milk samples) and the results are evaluated by HPLC method and amperometric methods.

Detection of Pesticide Residues (Fenitrothion) in Fruit Samples Based On Niobium Carbide@Molybdenum Nanocomposite: An Electrocatalytic Approach.

We have reported an effective electrochemical sensor for assorted pesticide (i.e., Fenitrothion). Exact tracking of these pesticides has become more important for protecting the environment and food resources owing to their high toxicity. Hence, the development of compatible sensors for the real-time detection of pesticides is imperative to overcome practical limitations encountered in conventional methodologies. In this regard, the role of the novel, advanced functional materials such as niobium carbide (NbC) supported on molybdenum nanoparticles (NbC@Mo) has drawn great consideration in conventional sensory systems because of their numerous advantages over other nanomaterials. The nanocomposite was characterized by XRD, XPS, HR-TEM, and EIS. Under optimized working conditions, the modified electrode NbC@Mo/SPCE responds linearly as 0.01-1889 µM concentration range and the detection limit is 0.15 nM. Most importantly, the method was successfully demonstrated in fruit samples.

Solvent Free Transesterification of Glycerol Into Glycerol Carbonate Over Nanostructured CaAl Hydrotalcite Catalyst.

Drastic increase in green house gases due to fossil fuels usage urges the mankind to look for alternative fuel resources. Biodiesel is one of the alternative fuels which attracted the attention of many researchers. In recent years, bio-diesel drags much attention as an alternative clean fuel. Glycerol is an unavoidable byproduct in the transesterification process of vegetable oils into bio diesel and therefore market is flooded with glycerol. So it is high time to find ways of utilizing the abundant glycerol into value added products. Herein we report the catalytic transesterification of glycerol using dimethyl carbonate over MgAl-hydrotalcite (MgAl-HT), CaAl-hydrotalcite (CaAl-HT) and nano structured CaAl-HT catalysts. All the catalysts were characterized by XRD, FT-IR, TPD-CO2, BET, SEM and HR-TEM techniques. Among them Ca4Al-HT was found to be best in terms of conversion of glycerol (82.4%) and selectivity (95.9%) towards glycerol carbonate. The effect of CTAB template concentration in the nano synthesis of Ca4Al-HT on conversion and selectivity was studied and Ca4Al-HT synthesized with 0.4 moles of CTAB showed the best conversion of glycerol (98.7%) and the highest selectivity towards glycerol carbonate (97.9%). The recyclability test performed with the best catalyst showed that the catalyst was recyclable even after 5 cycles. Valorization of glycerol yields glycerol carbonate (GC) which is a very good polar solvent with high boiling point, building block in several organic syntheses and used in the production of surfactants, poly urethanes etc.