Single Molecular Precursor Research Articles

Synthesis of Zinc Sulfide Luminescent Nanoparticles Using Zinc Metal Complexes of S-benzyl Dithiocarbonate via Microwave Irradiation Route

This paper reported highly luminous zinc sulfide (ZnS) nanoparticles grown by microwave-irradiated single molecular precursors. The precursor was obtained by Schiff bases of S-benzyl dithiocarbazate (SBDTC) ligand using 5-Bromo-4-hydroxy-3-methoxy-2-nitro Benzaldehyde; 4NNbiscyno diethylamino benzaldehyde and p-amino acetophenone. The nanoparticles obtained were characterized by X-ray diffraction studies for structural analysis, transmission electron micrographs (TEM) for morphological analysis, and UV-Vis spectra for optical analysis. X-ray diffractograms exhibit mixed structures analysis (wurtzite and cubic) for particles obtained using 5-Bromo-4-hydroxy-3-methoxy-2-nitro benzaldehyde and 4NNbiscyno diethylamino benzaldehyde. However, the particles obtained by p-amino acetophenone Schiff bases of SBDTC exhibit only wurtzite structure. Variation in optical properties is also observed with the precursors used. The excellent optical properties of ZnS nanoparticles signify the role of microwave irradiation in synthesis. The Photoluminescence (PL) study shows the luminescence in the visible region and the maximum intensity for ZnS particles obtained by zinc complex of p-amino acetophenone Schiff base of S-benzyl dithiocarbazate. The microwave-assisted process can be used for large-scale production of nanoparticles for emitting light in the visible region in various detecting and sensing applications.

Precursor engineering for soft selective synthesis of phase pure metal-rich digenite (Cu9S5) and djurleite (Cu31S16) nanocrystals and investigation of their photo-switching characteristics.

Copper sulfide nanostructures have evolved as one of the most technologically important materials for energy conversion and storage owing to their economic and non-toxic nature and superior performances. This paper presents a direct, scalable synthetic route aided by a single source molecular precursor (SSP) approach to access copper sulfide nanomaterials. Two SSPs, CuX(dmpymSH)(PPh3)2 (where X = Cl or I), were synthesized in quantitative yields and thermolyzed under appropriate conditions to afford the nanostructures. The analysis of the nanostructures through pXRD, EDS and XPS suggested that phase pure digenite (Cu9S5) and djurleite (Cu31S16) nanostructures were isolated from -Cl and -I substituted SSPs, respectively. The morphologies of the as-synthesized nanomaterials were investigated using electron microscopy techniques (SEM and TEM). DRS studies on pristine materials revealed blue shifted optical band gaps, which were found to be optimum for photoelectrochemical application. A prototype photoelectrochemical cell fabricated using the pristine nanostructures exhibited a stable photo-switching property, which presents these materials as suitable economic and environmentally friendly photon absorber materials.

Single source precursor mediated synthesis of phase pure digenite nanocrystals and investigation of its photo-switching behavior

Copper sulfide nanostructures have garnered strategic importance in green energy applications due to their economic nature and impressive performances. This account presents a straightforward and scalable route to access digenite (Cu1.8S or Cu9S5) phase of copper sulfide in nano-dimension. The synthesis is facilitated through low temperature rapid thermolysis of a newly synthesized and structurally characterized single source molecular precursor, namely [Cu(Spyz-2)(PPh3)2]·MeOH (1). The crystal structure, phase purity, and morphology of the nanostructures were thoroughly examined by PXRD and electron microscopic techniques. The average crystallite size and morphology of the nanostructures were found to be the function of the different capping agents (OAm and DDT) employed for the synthesis. DRS studies on the nanomaterials revealed blue shifted optical band gap (2.09–2.13 eV) which were found to be optimum for photoelectrochemical application. A prototype photoelectrochemical cell, fabricated using the pristine nanostructures exhibit high photocurrent generation along with nice photo-switching property which pose them as suitable alternatives for green energy applications and environmental remediation.

Interplay of Kinetic Limitations and Disintegration: Selective Growth of Hexagonal Boron Nitride and Borophene Monolayers on Metal Substrates.

The CVD growth of bielemental 2D-materials by using molecular precursors involves complex formation kinetics taking place at the surface and sometimes also subsurface regions of the substrate. Competing microscopic processes fundamentally limit the parameter space for optimal growth of the desired material. Kinetic limitations for diffusion and nucleation cause a high density of small domains and grain boundaries. These are usually overcome by increasing the growth temperature and decreasing the growth rate. In contrast, the nature of molecular precursors with limited thermal stability can result in dissociation and preferential desorption, leading to an undesired or ill-defined composition of the 2D-material. Here we demonstrate these constraints in a combined low-energy electron diffraction and low-energy electron microscopy study by examining the selective formation of single-layer hexagonal boron nitride (hBN) and borophene on Ir(111) using a borazine precursor. We derive a temperature-pressure phase diagram and apply classical nucleation theory to describe our results. By considering the competing processes, we find an optimum growth temperature for hBN of 950 °C. At lower temperatures, the hBN island density is increased, while at higher temperatures the precursor disintegrates and borophene is formed. Our results introduce an additional aspect that must be considered in any high-temperature growth of bielemental 2D-materials from single molecular precursors.

(Z)-2-(pyrrolidin-2-ylidene) thiourea based nickel (II) complex as a single source precursor for the synthesis of NiS nanoparticles and thin films

Nickel sulfides nanocrystals may be regarded as promising of materials in different research areas such as catalysts, solar cells, and electrode-materials. (Z)-2-(pyrrolidin-2-ylidene) thiourea ligand and (Z)-2-(pyrrolidin-2-ylidene) thiourea based nickel (II) complex have been prepared and utilized as single source molecular precursor for the synthesis of nickel sulfide nanoparticles and thin films. The effect of temperature was studies during the synthetic processes. The synthesized nanomaterials were characterized with various instruments. UV-Vis spectroscopy results of the nanoparticles were red shifting when the reaction temperature was increased whereas the blue shift was observed when the temperature was elevated during the preparation of the NiS thin films with the optical band gap energies ranging from 2.79 eV - 3.56 eV. All the XRD patterns for the NiS thin films confirm the predominance of pure hexagonal phase.

Molecular Precursor-Driven Synthesis of Copper Telluride Nanostructures for LIB Anode Application.

Copper tellurides have garnered substantial interest for their applicability as an electrocatalyst for water splitting, battery anodes and photodetectors, etc. Moreover, synthesis of phase pure metal tellurides using the multi-source precursor method is challenging. Therefore, a facile synthesis protocol for copper tellurides is anticipated. The current study involves a simplistic single source molecular precursor pathway for the synthesis of orthorhombic-Cu2.86Te2 nano blocks and -Cu31Te24 faceted nanocrystals employing the [Cu{TeC5H3(Me-5)N}]4 cluster in thermolysis and pyrolysis, respectively. The pristine nanostructures were carefully characterized by powder X-ray diffraction, energy-dispersive X-ray spectroscopy, electron microscopic techniques (scanning electron microscopy and transmission electron microscopy), and diffuse reflectance spectroscopy to know the crystal structure, phase purity, elemental composition, distribution of elements, morphology, and optical band gap. These measurements suggests that the reaction conditions fetch nanostructures of different sizes, crystal structures, morphologies, and band gaps. As prepared nanostructures were evaluated for lithium-ion batteries (LIBs) anode material. The cells fabricated with orthorhombic Cu2.86Te2 and orthorhombic Cu31Te24 nanostructures deliver capacities of 68 and 118 mA h/g after 100 cycles. The LIB anode made up of Cu31Te24 faceted nanocrystals exhibited good cyclability and mechanical stability.

Direct Synthesis of Two-Dimensional SnSe and SnSe2 through Molecular Scale Preorganization.

Two-dimensional tin monoselenide (SnSe) and tin diselenide (SnSe2) materials were efficiently produced by the thermolysis of molecular compounds based on a new class of seleno-ligands. Main group metal chalcogenides are of fundamental interest due to their layered structures, thickness-dependent modulation in electronic structure, and small effective mass, which make them attractive candidates for optoelectronic applications. We demonstrate here the synthesis of stable tin selenide precursors by in situ reductive bond cleavage in the dimeric diselenide ligand (SeC2H4N(Me)C2H4Se)2 in the presence of SnCl4. New molecular precursors [SnIV(SeC2H4N(Me)C2H4Se)2], [SnIVCl2(SeC2H4N(Me)C2H4Se)], and [SnIV(SC2H4N(Me)C2H4S)(SeC2H4N(Me)C2H4Se)] were thoroughly characterized by multinuclear magnetic resonance studies and single-crystal X-ray diffraction analysis that revealed the Sn(IV) center to be octahedrally coordinated by two tridentate dianionic chelating ligands or trigonally pyramidally coordinated by one chelating ligand and two chlorido ligands. Preorganization of metal-selenium bonds in both compounds offered direct and reproducible synthetic access to two-dimensional tin chalcogenides (SnSe and SnSe2) via simple adjustment of the pyrolysis temperature. Additionally, SnSe2 and SnSxSe2-x particles could be successfully synthesized by microwave-assisted decomposition of the molecular precursors, which was unambiguously corroborated by both experimental and computational analyses that explained the formation of a selenium rich SnSxSe2-x phase from a single molecular precursor containing both Sn-Se and Sn-S bonds.

Synthesis and Spectroscopic Characterization of Zinc Sulphide nanoparticles using Microwave irradiation of Zinc complex of Thiosemicarbazone ligand as a Single Molecular precursor : Pharmacological activities

Single molecular precursors are appropriate starting materials for synthesis of semiconductor nanoparticles (NPs), which allow for the control of atomic ratio, monodispersity, composition and particle size of nanoscaled metallic sulfide nanoparticles. In the present study, we have reported the synthesis of nanostructured chalcogenides pharmacologically active active zinc sulfide nanoparticles (ZnS NPs) using Zn (II) ion inserted thiosemicarbazone ligand as a single molecular precursor .The precursors were thermally pyrolysized using high energy microwave radiations to obtain very fine ZnS nanoparticles. In this synthesis, we use DMSO as a nonpolar solvent for the synthesis of all compounds. The heating of Zinc complex in the non- aqueous environment of DMSO plays a very crucial role in decreasing reaction time, reducing the chances of side reactions and proper conversion of Zn complex into ZnS nanoparticles. In this reaction Zn complex of thiosemicarbazone ligand provides both Zn2+ and S2- ions for synthesis of ZnS nanoparticles. The microwave synthesis of ZnS NPs from Zn complex is a very simple, fast, highly effective, efficient and low cost method. All synthesized compounds were characterized by various structural, electronic, vibrational, optical, morphological and pharmacological characterizations. The prepared ZnS NPs were found to crystallize in cubic phase, which generally forms at low temperatures, with the dimensions dependent upon the molar ratio of molecular precursors used. Synthesized ZnS nanomaterials had surface sulfur vacancies that extend their absorption spectra towards the visible region and decreased the bond gap. This allowed ZnS nanoparticles to demonstrate various pharmacological activities like antibacterial, antioxidant and anti-inflammatory activities under normal conditions. Powered X-ray diffraction studies confirms the formation of well -defined equispaced crystalline ZnS NPS. TEM and FE SEM microscopic studies confirmed the elongated tubules structure of ZnS NPs with an average particle size of 60 nm. Sharpe electronic absorption band at 390 nm indicates the synthesis of good quality ZnS NPs. The FT-IR spectral studies confirmed the presence of Zn-S stretching, N-H bending and C=N stretching, vibrations in molecular precursor as Zn(II) complex. The thermal analysis of molecular precursor was performed to investigate the thermal stability of zinc complex. The Zn complex was stable up-to 3800 c. All synthesized compounds demonstrated excellent pharmacological activities like antibacterial, antioxidant and antiinflammatory activities as compared to standards used in analysis of compounds. The microwave synthesis of ZnS nanoparticles via single molecular precursor in proper stoichiometric ratios is an excellent and an efficient method for synthesizing highly effective bioactive agents which can be considered as good drug candidate for the treatment of various diseases in future

The formation of SnS nanorods orthorhombic phases grown from different molecular precursors

The high theoretical ability of the tin sulfide (SnS) semiconductor makes it a potential material for solar cell applications. However, employing an environmentally friendly and cost-effective framework for the synthesis of SnS sustainable materials is essential. The attraction of the single-source precursor (SSP) route of preparing flexible nanostructured metal sulfide is due to its simplified procedures, high efficiency, fewer reagents and scale-up abilities. In this study, SSP route was used to prepare SnS nanoparticles with tunable sizes and better morphologies from three molecular precursors. XRD shows the structural characteristics of the three samples confirm the presence of orthorhombic phases for SnS1, SnS2 and SnS3. HRTEM images for SnS2 and SnS3 display irregular orthorhombic phases with an average size of 17.11 nm and 3.38–4.19 nm as compared to SnS1, which reveals a spherical structure and a grain size of 2.22–3.33 nm. There have been very few studies that have established nanorods SnS, but none from a single molecular precursor.

Roles of TOPO Coordinating Solvent on Prepared Nano-Flower/Star and Nano-Rods Nickel Sulphides for Solar Cells Applications.

The present study describes a cheap, safe, and stable chemical process for the formation of nickel sulphide (NiS) with the use of mixed and single molecular precursors. The production pathway is uncomplicated, energy-efficient, quick, and toxic-free, with large-scale commercialization potential. The obtained results show the effect of tri-N-octylphosphine oxide (TOPO) as a coordinating solvent on the reaction chemistry, size distributions, morphology, and optical properties of both precursors. Ni[N,N-benz-N-p-anisldtc] as NiSa, Ni[N,N-benzldtc] as NiSb, and Ni[N-p-anisldtc] as NiSc thermally decompose in a single step at 333–334 °C. The X-ray diffraction peaks for NiSa, NiSb, and NiSc matched well with the cubic NiS nanoparticles and corresponded to planes of (111), (220), and (311). The extrapolated linear part from the Tauc plots reveals band gap values of 3.12 eV, 2.95 eV, and 2.5 eV, which confirms the three samples as potential materials for solar cell applications. The transmission electron microscopy (TEM) technique affirmed the quantum dot size distribution at 19.69–28.19 nm for NISa, 9.08–16.63 nm for NISb, and 9.37–10.49 nm for NISc, respectively. NiSa and NiSc show a clearly distinguishable flower/star like morphology, while NiSb displays a compact nano-rod shape. To the best of the authors’ knowledge, very few studies have been reported on the flower/star like and nano-rod shapes, but none with the dithiocarbamate molecular precursor for NiS nanoparticles.

Cytotoxic activity and DNA fragmentation study of nano structured assemblies of copper sulfide nanoparticles using single route molecular precursor source of copper

In this paper, we have reported an easy, template free and squashy solution chemistry path was applied to synthesize variegated nanostructured congregation assemblies of copper nanoparticles at room temperature using hydrazinecarbothioamide coordinated Cu(II) complex through a single route molecular precursor source. The parent compounds were heated under microwave irradiation to obtain diversified CuS nanostructures in the shapes of spheres and nanotubes were found to be assemblies of either nanoplates or nanoparticles. The formation of nanostructured CuS nano particles was detailed studied by differing the synthetic conditions such as reaction time, temperature, parent compounds ratio, and the presence of counter ions. The presence of NO3 - and SO4 2- ions as counter ions were found to be suitable for the formation of nanotubes whereas the presence of Clions initiate the formation of spherical nano assemblies of CuS nano material is obtained. The synthesized samples were characterized using various structural, morphological and optical characterization techniques like elemental analysis, FT-IR, UV-Vis, and thermogravimetric analysis/differential thermogravimetric (TGA/DG). Important changes were observed in the FT-IR spectra of the copper complex compared to the FT-IR spectrum of ligand. X-ray diffraction studies confirms the formation of hexagonal crystalline phase of CuS nano particles: Transmission electron microscopy exhibit nanotube like structures with an average particle size of 78nm. Strong UV absorption band at 425nm confirms the formation of good quality CuS nano particles. The microwave irradiation of parent compounds in the presence of nonpolar solvents like DMF, DMSO environment played a significant role in decreasing the reaction time, decreases the possibility of side reactions and proceeds the reaction in the formation of good quality nanoparticles. The SEM analysis of CuS nano particles confirms the agglomerated grain like surface morphology of nanoparticles. All compounds showed the various pharmacological activities like antioxidant, antibacterial activities due to the presence of strong electron withdrawing and electron releasing functional groups are present in molecular precursors. The microwave synthesis of CuS nanostructured assemblies in nonpolar solvent in a proper stoichiometric ratio is an excellent method for preparing highly efficient bio active agents like antibacterial & antioxidant agents which can be considered as a good drug candidate for medicinal chemists in future.

Step-Assisted On-Surface Synthesis of Graphene Nanoribbons Embedded with Periodic Divacancies.

The bottom-up approach through on-surface synthesis of porous graphene nanoribbons (GNRs) presents a controllable manner for implanting periodic nanostructures to tune the electronic properties of GNRs in addition to bandgap engineering by width and edge configurations. However, owing to the existing steric hindrance in small pores like divacancies, it is still difficult to embed periodic divacancies with a nonplanar configuration into GNRs. Here, we demonstrate the on-surface synthesis of atomically precise eight-carbon-wide armchair GNRs embedded with periodic divacancies (DV8-aGNRs) by utilizing the monatomic step edges on the Au(111) surface. From a single molecular precursor correspondingly following a trans- and cis-coupling, the DV8-aGNR and another porous nanographene are respectively formed at step edges and on terraces at 720 and 570 K. Combining scanning tunneling microscopy/spectroscopy, atomic force microscopy, and first-principles calculations, we determine the out-of-plane conformation, wide bandgap (∼3.36 eV), and wiggly shaped frontier orbitals of the DV8-aGNR. Nudged elastic band calculations further quantitatively reveal that the additional steric hindrance effect in the cyclodehydrogenative reactions has a higher barrier of 1.3 eV than that in the planar porous nanographene, which also unveils the important role played by the monatomic Au step and adatoms in reducing the energy barriers and enhancing the thermodynamic preference of the oxidative cyclodehydrogenation. Our results provide the first case of GNRs containing periodic pores as small as divacancies with a nonplanar configuration and demonstrate the strategy by utilizing the chemical heterogeneity of a substrate to promote the formation of novel carbon nanomaterials.

Synthesis of SiC films by Atmospheric Pressure Chemical Vapor Deposition using Dimethylisopropylsilane Polymeric Precursor

Abstract: Silicon carbide (SiC) thin films were deposited on Quartz, SiC, and GaAs substrates under a hydrogen (H2) ambient at 850°C using dimethylisopropylsilane [CH(CH3)2SiH(CH3)2] as a single molecular polymeric precursor by the atmospheric pressure chemical vapor deposition (APCVD) technique. Effects on the SiC films from variation of precursor to H2 flow ratio in the reactive chamber as well as those which resulted when vacuum or positive pressures are utilized during temperature ramping have been investigated. Detailed analysis of Fourier Transform Infrared Spectroscopy (FTIR) results indicate the formation of SiC at 850°C in accordance with residual Si-CH2, Si-CH3 and Si-O bonds. Confirmed by either X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) or Energy Dispersive Spectroscopy (EDS), results show that the produced SiC films are dense, rough surfaced, void-free, and consist of a crystalline core showing the presence of beta-SiC and small amounts of alphaSiC. Pre-experimental thermodynamic modeling provided the valuable insight that an increase of the precursor to direct H2 flow ratio would provide a decrease of unreacted carbon in the SiC matrix yielding higher quality SiC films. These simulations also have shown reasonable agreement with our experimental observations. Keywords: SiC thin Film, Polymeric Precursor, Chemical Vapor Deposition, Thermodynamic Modelling

A Highly Active Nitrogen‐Doped Mixed‐Phase Mixed‐Valence Cobalt Nanocatalyst for Olefins and Nitroarenes Hydrogenation

AbstractDevelopment of an inexpensive, environmentally friendly and robust recyclable heterogeneous catalyst for alkene and nitroarene hydrogenation is in high demand for the sustainable future of chemical industries. Herein, we have synthesize and characterized a trinuclear mixed valence cobalt complex 1 and nitrogen doped mixed phase cobalt (β‐Co(OH)2 and CoO) nanocatalyst (N@MPCoNC) as reported earlier. N@MPCoNC was synthesized via single source molecular precursor by reducing 1 by aq. N2H4 followed by calcinations. Both mixed‐valence cobalt metal complex (1) and nitrogen doped mixed phase cobalt nanocatalyst (N@MPCoNC) were utilized for alkenes and nitroarenes hydrogenation reaction, however excellent catalytic activity was noticed by N@MPCoNC with the 100 % conversion of styrene and 4‐nitrotoluene to the corresponding ethylbenzene and 4‐aminotoluene with 100 % selectivity under mild reaction condition. The scope of the heterogeneous N@MPCoNC was further evaluated for other alkenes and nitroarenes to obtain corresponding alkanes and aminoarenes with an excellent conversion and high selectivity at room temperature.

Critical Optimization of Phosphorus Functionalized Carbon Nanomaterials for Metal‐Free Solar Hydrogen Production and Simultaneous Organic Transformation

AbstractComplete metal‐free P‐functionalized carbon nanomaterials are synthesized from a single molecular precursor, phytic acid, for photocatalytic solar H2 production and simultaneous organic transformation of 4‐methyl benzyl alcohol to 4‐methyl benzaldehyde by managing the complete redox cycle. It is observed that by increasing the carbonization time, P‐functionalized amorphous carbon dots convert to the highly defined 2D sheet‐like nanostructure with optimum P‐functionality, resulting in efficient light absorption, charge separation, and improved active sites for photocatalysis. Finally, the highly defined sheet‐like structure converts to a more defected aggregated form, resulting in the depletion of photocatalytic efficiency. The structural and elemental features are further correlated with the ongoing photophysics by means of steady‐state and time‐resolved fluorescence spectroscopy. Transient photocurrent responses and Mott‐Schottky plots directly support the optimization of P‐functionalized carbon nanostructure for efficient photocatalysis. Finally, the detailed computational studies are carried out to unveil the charge separation mechanism and the crucial role of P‐functionalities as active sites for better charge accumulation as well as H2O adsorption on the surface. Overall, the in‐depth structure–property correlation and critical optimization of the heteroatom functionalized carbon nanomaterials will open up new possibilities for further development of metal‐free photocatalysts for solar‐energy conversion devices.

Molecular precursor driven synthesis of phase pure tin sulfide nanosheets and investigation of their photoresponsive behaviour

Tin Sulfide (SnS) has emerged as an important semiconductor for photovoltaics, thermoelectric and as high-capacity anode material for alkali-ion batteries. However, producing phase pure SnS free from higher tin sulfides (SnS2 and Sn2S3) having different optoelectronic properties, is a challenging task. In this report, we present a structurally characterized single source molecular precursor (SSP), [tBu2Sn(SpymMe2)2], for the facile synthesis of phase pure orthorhombic SnS nanosheets in different high boiling solvents (oleylamine, octadecene, dodecanthiol) with varying coordination ability. As-prepared SnS nanosheets were thoroughly checked for its phase purity, elemental composition and morphology through pXRD and electron microscopic techniques. A distinct variation in crystallite size, morphology and band gap of nanosheets as function of reaction solvent was observed during investigation. Finally, the as prepared SnS nanosheets derived from SSP exhibit high photoresponsitivity and photostability which make them promising candidate for alternative low-cost photon absorber material.

Synthesis of photoresponsive and photoemissive ultrathin 2D nanosheets of In2S3 achieved through a new single source molecular precursor.

Indium sulfide, a two-dimensional semiconductor material, has emerged as a promising candidate for cost-effective and sustainable solar cells. This report deals with the facile preparation of colloidal In2S3 with a new ultrathin nanosheet (NS) morphology. The synthesis was mediated through a new structurally characterized single source molecular precursor. The crystal structure, phase purity, and morphology of the NSs were thoroughly investigated by pXRD, Raman, XPS, and electron microscopic techniques. AFM studies revealed that the NSs have an average thickness of ∼1.76 nm. The optical studies confirm quantum confinement in the as-prepared NSs with a blue shift in the direct band gap, which lies in the optimal range suitable for solar cell application. Furthermore, photoluminescence studies indicate strong emission by these NSs in the blue region. The as-synthesized In2S3 NSs-based prototype photoelectrochemical cell exhibit high photostability and photoresponsivity, which make them suitable candidates for sustainable solar cells.

Molecular precursor-mediated facile synthesis of photo-responsive stibnite Sb2S3 nanorods and tetrahedrite Cu12Sb4S13 nanocrystals.

Stibnite Sb2S3 and tetrahedrite Cu12Sb4S13 nanostructures being economical, environmentally benign and having a high absorption coefficient are highly promising materials for energy conversion applications. However, producing these materials especially tetrahedrite in the phase pure form is a challenging task. In this report we present a structurally characterized single source molecular precursor [Sb(4,6-Me2pymS)3] for the facile synthesis of binary Sb2S3 as well as ternary Cu12Sb4S13 in oleylamine (OAm) at a relatively lower temperature. The as-prepared Sb2S3 and Cu12Sb4S13 nanostructures were thoroughly checked for their phase purity, elemental composition and morphology by powder X-ray diffraction (pXRD), electron dispersive spectroscopy (EDS) and electron microscopy techniques. pXRD and EDS studies confirm the formation of phase pure, crystalline orthorhombic Sb2S3 and cubic Cu12Sb4S13. The SEM, TEM and HRTEM images depict the formation of well-defined nanorods and nearly spherical nanocrystals for Sb2S3 and Cu12Sb4S13, respectively. The Sb2S3 nanorods and Cu12Sb4S13 nanocrystals exhibit an optical bandgap of ∼1.88 and 2.07 eV, respectively, which are slightly blue-shifted relative to their bulk bandgap, indicating the quantum confinement effect. Finally, efficient photoresponsivity and good photo-stability were achieved in the as-prepared Sb2S3 and Cu12Sb4S13 nanostructure-based prototype photo-electrochemical cell, which make them promising candidates for alternative low-cost photon absorber materials.

Advanced MoS2 nanocomposite materials for the synthesis of valuable pharmaceuticals

Rampant industrialization has played pivotal role in generation of polluting materials threatening ecology, environment and biosphere reserves. Amongst various pollutants, nitroarmatics are key components of non-biodegradable organic dyes, insecticides having toxic and carcinogenic effect on human health. Furthermore, aromatic hydrocarbons are widespread contaminants of ground water. Therefore, these waste materials are generally degraded by advanced oxidation process to carbon dioxide and water. But, these organic waste materials instead of complete mineralization can be valorized to valuable pharmaceuticals. For example, nitroaromatics can be valorized to tertiary amine or N-Mannich bases. N-Mannich bases are important pharmacophores and used as anti-microbial, anti-viral, anti-HIV, anti-inflammatory, analgesics and RSK2 inhibitory. Ethylbenzene is an important industrial waste can be used as building block for the synthesis of α-ketoamides. These α-ketoamides are significant pharmacophores can be used as the broad-spectrum antibiotics for COVID-19. Presently, COVID-19 is a global pandemic affecting billions of people. To deliver doses to such a big population would be a challenge. Therefore, we can use the industrial waste materials for the synthesis of valuable pharmacophors to boost the economy. To effectively catalyze the transformation of these industrial wastes into valuable products, cost-effective, readily available catalytic materials will be investigated. Earth abundant transition metals like Cu, Co, Zn, Ni, Zr etc. supported over 2D transition metal dichalcogenides can be used as the desirable candidates for the synthesis of pharmacophors from industrial waste. These catalytic materials will be prepared by hydrothermal or reverse micelle microemusion technique form metal salts or metal dithiocarbamates based single source molecular precursors.

Facile one pot synthesis of highly photoresponsive coinage metal selenides (Cu1.8Se and Ag2Se) achieved through novel Cu and Ag pyridylselenolates as molecular precursors

Phase pure Cu1.8Se and Ag2Se nanostructures were synthesized employing novel single source molecular precursors at relatively low temperature. These materials exhibit good photoresponsivity and stability under alternating light and dark conditions.