Solventless Synthesis of Zinc Sulphide Nanoparticles from Zinc Bis(diethyldithiocarbamate) as a Single Source Precursor

This study explores the synthesis of nanoparticles through the thermal decomposition of single-source precursors, a method gaining popularity due to its low cost, minimal environmental toxicity, rapidity, scalability, and the ability to form nanoparticles with few defects. Zinc ethyl carbamate was synthesized and characterized using 1H NMR and infrared spectroscopy. Its purity was confirmed through microelemental analysis and melting point determination. The melting point of the complex was determined to be 165 °C. The thermogravimetric analyses indicated a one-step decomposition of zinc ethyl carbamate with a decomposition onset of of 200 °C, yielding a stable ZnS residue. Further thermal decomposition led to the formation of wurtzite phase ZnS nanoparticles, as evidenced by XRD. SEM micrographs displayed mixed spherical, and cubic unevenly sized, polydispersed nanoparticles, while EDX revealed approximately a 1 : 1 Zn to S ratio. Estimated band gap from the Tauc's plot gave 3.93 eV and 3.42 eV for the nanoparticles synthesized at 300 and 400 °C respectively. The wide difference in the band gaps may be as a result of the larger particles observed at 400 °C and the deformations in the sample as observed in the SEM.

Tuning composition of CuCo2S4-NiCo2S4 solid solutions via solvent-less pyrolysis of molecular precursors for efficient supercapacitance and water splitting

Mixed metal sulfides are increasingly being investigated because of their prospective applications for electrochemical energy storage and conversion. Their high electronic conductivity and high density of redox sites result in significant improvement of their electrochemical properties. Herein, the composition-dependent supercapacitive and water splitting performance of a series of Ni_(1−x)Cu_xCo₂S₄ (0.2 ≤ x ≤ 0.8) solid solutions prepared via solvent-less pyrolysis of a mixture of respective metal ethyl xanthate precursors is reported. The use of xanthate precursors resulted in the formation of surface clean nanomaterials at low-temperature. Their structural, compositional, and morphological features were examined by p-XRD, SEM, and EDX analyses. Both supercapacitive and electrocatalytic (HER, OER) properties of the synthesized materials significantly vary with composition (Ni/Cu molar content). However, the optimal composition depends on the application. The highest specific capacitance of 770 F g⁻¹ at a current density of 1 A g⁻¹ was achieved for Ni_0.6Cu_0.4Co₂S₄ (NCCS-2). This electrode exhibits capacitance retention (C_R) of 67% at 30 A g⁻¹, which is higher than that observed for pristine NiCo₂S₄ (838 F g⁻¹ at 1 A g⁻¹, 47% C_R at 30 A g⁻¹). On the contrary, Ni_0.4Cu_0.6Co₂S₄ (NCCS-3) exhibits the lowest overpotential of 124 mV to deliver a current density of 10 mA cm⁻². Finally, the best OER activity with an overpotential of 268 mV at 10 mA cm⁻² was displayed by Ni_0.8Cu_0.2Co₂S₄ (NCCS-1). The prepared electrodes exhibit high stability, as well as durability.

A multi-component CuCo₂S₄ and NiCo₂S₄ thiospinel solid solution is prepared over an entire range by a low-temperature solvent-less route. The synergistic effect from both thiospinels on water splitting and capacitance is studied.

N-Naphthoyl Thiourea Derivatives: An Efficient Ultrasonic-Assisted Synthesis, Reaction, and In Vitro Anticancer Evaluations

This work demonstrates the optimization of an efficient, mild, and environmentally friendly synthetic approach to access a diverse library of N-naphthoyl thioureas. These derivatives could be exploited as precursor scaffolds for designing valuable heterocycles with anticipated biological activities. Additionally, the utilization of a copper complex derived from the newly synthesized N-naphthoyl thiourea ligand in the photodegradation of methyl orange (MO) dye was explored. The antiproliferative effect of the synthesized derivatives was examined against MCF-7, HCT116, and A549 cancer cell lines. Most of the assembled derivatives revealed a significant cytotoxic effect, in some cases, greater than doxorubicin. Of these, the copper complex demonstrated significant antitumor activities (IC₅₀ < 1.3 μM) and lesser cytotoxic impact (IC₅₀ > 76 μM), indicating its possibility as a pioneering candidate for future carcinogenic pharmaceutics. Relations between the structure and activity also have been addressed.

Acylselenoureas, selenosemicarbazones and selenocarbamate esters: Versatile ligands in coordination chemistry

Acylselenoureas, selenosemicarbazones and selenocarbamate esters from complexes with various transition- and main-group-metals, adopting several coordination modes.

Synthesis of a Novel Single-Source Precursor for the Production of Lead Chalcogenide Thin Films

A novel complex [Pb((SePiPr2)2N) (S2CNEt2)] has been synthesized and characterized by microelemental analysis, melting point NMR, and FT-IR spectroscopies. Its crystal structure has also been successfully determined using single-crystal X-ray crystallography. The structure indicates a distorted square pyramidal geometry with the four basal atoms being noncoplanar. The complex was used as a single-source precursor for the deposition of lead chalcogenide thin films on glass substrates at 300, 350, 400, and 450°C by AACVD. The films were characterized by SEM, EDX, and XRD. The XRD peaks matched with cubic PbSe at all temperatures. The SEM micrographs showed the formation of cubes with the lower temperatures (300–350°C) showing well-resolved cubes while with the higher temperatures (400–450°C) showing poorly resolved cubes. The EDX analyses confirmed the formation of PbSe thin films at all the deposition temperatures.

Selenium and sulfur inhomogeneity in free-standing ternary Sb2(Se,S)3 alloyed nanorods

Chalcogen inhomogeneous distributions, i.e., S decreases but Se increases from the center to the periphery, are found in ternary Sb₂(Se,S)₃ alloyed nanorods synthesized with SeS₂ as a molecular precursor.

Acylselenoureato bis(chelates) of lead: synthesis, structural characterization and microwave-assisted formation of PbSe nano- and microstructures

Three lead(ii) bis(acylselenoureato) complexes were prepared by reaction of the respective acylselenourea compounds with Pb(OAc)₂. One of these lead complexes was converted into PbSe nano- and microstructures by microwave-assisted synthesis.

Lead ethyl dithiocarbamates: efficient single-source precursors to PbS nanocubes

Lead ethyl dithiocarbamates have been successfully used as single-source precursors for the deposition of PbS using spin coating followed by annealing at moderate temperatures. The thin films were characterized using a powder X-ray diffractometer and were found to be face-centred cubic with the (200) plane being the most preferred orientation. Scanning electron microscopy images showed the formation of well-defined cubes. Optical band gaps of PbS thin films were estimated using Tauc plots as 0.72, 0.73 and 0.77 eV at annealing temperatures of 250, 300 and 400°C. These band gaps were all blue shifted from the bulk value of 0.41 eV. Energy-dispersive X-ray analysis was used to determine the composition of the thin films which showed an approximately 1 : 1 Pb to S ratio.

Microwave-assisted synthesis of PbS nanostructures

The synthesis of PbS nanostructures by microwave irradiation of single source precursor compounds in ethyleneglycol medium is reported. Pb(II) bis(N-ethyl-N-phenyldithiocarbamate) and Pb(II) bis(N-butyl-N-phenyldithiocarbamate) represented as complexes (1) and (2) respectively were utilised. The prepared PbS nanostructures were characterized using X-ray diffraction (XRD), Transmission electron microscopy (TEM), and absorption spectroscopy. The results showed that complex (1) can project the formation of nanorod with (111) basal plane, while (2) project the formation of nanocube with (001) basal plane. The formation of different morphologies in ethylene glycol may also be due to the selective binding to specific crystallite facets of the PbS through the hydroxyl groups of ethylene glycol. In the nanorod, the selective stabilization of the (111) face of PbS, resulted in anisotropic growth along the (100) face. The high resolution TEM images showed distinct lattice fringes which confirmed the crystallinity of the nanostructures. The band gap energies were obtained as 1.10 and 1.12 eV for the nanorods and nanocubes respectively, a significant blue shift from the bulk value (0.4 eV) which could be ascribed to quantum confinement effect. The result established the significant effect of the precursor type on the morphologies of the PbS.

Electrochemical investigation of uncapped AgBiS2 (schapbachite) synthesized using in situ melts of xanthate precursors

In this study, a facile and potentially scalable synthesis of AgBiS2 (schapbachite) using melts of metal xanthates is presented; AgBiS2 is both a significant mineral and a technologically important material. This ternary material was synthesized by a novel and low-cost solventless route using simple ethyl xanthate complexes of silver and bismuth. p-XRD analysis indicates that the synthesized ternary material is highly crystalline and belongs to the cubic phase (schapbachite). The electrochemical properties of the material were tested; the potential of the synthesized material for application in charge storage shows a high specific capacitance of 460 F g-1 at 2 mV s-1. A capacitance retention of 83% with a 100% coulombic efficiency was observed after 3000 cycles. The charge storage potential, analysed by fabricating actual symmetrical devices, shows a specific capacitance of 14 F g-1 at 2 mV s-1. An energy density of 26 W h kg-1 and a power density of 3.6 kW kg-1 were observed. Besides, the potential for the oxygen evolution reaction was also studied. An overpotential of 414 mV and a Tafel slope of 134 mV dec-1 were obtained for water oxidation. The fabrication of an electrolyzer cell using the synthesized material as the cathode indicates that a current of 10 mA cm-2 can be achieved at a potential of 1.63 V.

Phase transition in Cu2+xSnS3+y (0 ≤ x ≤ 2; 0 ≤ y ≤ 1) ternary systems synthesized from complexes of coumarin derived thiocarbamate motifs: optical and morphological properties

Tetragonal Cu₂SnS₃ and orthorhombic Cu₄SnS₄ nanocubes were synthesized by a heat up procedure with oleylamine (OLA) and dodecanethiol (DT) acting as both solvent and capping ligands. Both mohite–anorthic and monoclinic phases were obtained from the same variant of precursors mixture, by hot injection synthesis, at 200 and 250 °C. Changing the reaction conditions also leads to the formation of different morphologies. When OLA was used as a solvent, nanosheets or nanocubes were obtained, while the reaction with DT resulted in the formation of particles in the form of nanohexagons. The growth process of copper tin sulphide starts with the formation of Cu⁺ seeds, followed by the oxidation of Sn²⁺ to Sn⁴⁺. Dodecanethiol was an additional source of sulphur. The overall reaction leads to the formation of either phase pure Cu₂SnS₃ or Cu₄SnS₄, depending on the reaction conditions, with band-gap energies of 1.05–1.45 eV, which are in the optimum range for photovoltaic applications.

Tetragonal Cu₂SnS₃ and orthorhombic Cu₄SnS₄ nanocubes were synthesized by a heat up procedure with oleylamine (OLA) and dodecanethiol (DT) acting as both solvent and capping ligands.