Phase Evolution of CuS System in Ethylene Glycol Solution: the Effect of Anion and PVP on the Transformation of Thiourea

Inhibition Effect and Mechanism of Thiourea on Electrophilic Chlorination of Aromatics in Combustion Flue Gas

Thiourea can effectively inhibit the formation of highly toxic chlorinated aromatics in postcombustion zone. However, the inhibition mechanism was still not adequately understood. In this study, naphthalene was adopted as a model aromatic compound to investigate the inhibition effect and mechanism of thiourea on the formation of chlorinated aromatics via electrophilic chlorination over Cu and Fe chlorides. Thiourea addition resulted in the reductions of 77.6-99.8% and 36.4-98.1% in the yield of polychlorinated naphthalenes from naphthalene chlorination mediated by CuCl₂ and FeCl₃ at 150-300 °C, respectively. The inhibition efficiency of chlorination presented a decreasing tendency with increasing reaction temperature and O₂ content in flue gas. X-ray diffraction analysis revealed that the thiourea-induced reduction of highly active Cu (II) and Fe (III) chlorides to less active Cu (I) and Fe (II) chlorides was a primary mechanism for inhibiting aromatic chlorination. [thiourea-Cu]⁺ complex generated during the reduction process could be transformed into CuS and Cu₂S, and isomeric reaction product NH₄SCN could react with Cu²⁺ to produce Cu(SCN)₂ and then also form Cu sulfides, suggesting sulfidization of Cu chloride was another important inhibition mechanism. Chlorination inhibition induced by the volatile decomposition products of thiourea might only play a minor role.

One-pot hydrothermal synthesis of CdS decorated CuS microflower-like structures for enhanced photocatalytic properties

CdS decorated CuS structures have been controllably synthesized through a one-pot hydrothermal method. The morphologies and compositions of the as-prepared samples could be concurrently well controlled by simply tuning the amount of CdCl2 and thiourea. Using this strategy, the morphology of the products experienced from messy to flower-like morphologies with multiple porous densities, together with the phase evolution from pure CuS to the CdS/CuS composites. Serving as a photocatalyst, the samples synthesized with the addition of 1 mmol cadmium chloride and 3 mmol thiourea during synthetic process, showed the best photocatalytic activity, which could reach a maximum photocatalytic efficiency of 93% for methyl orange (MO) photodegradation after 150 min. The possible mechanism for the high photocatalytic efficiency of the sample was proposed by investigating the composition, surface area, structure, and morphology before and after photocatalytic reaction.

Facile one-step mechanochemical synthesis of [Cu(tu)]Cl·1/2H2O nanobelts for high-performance supercapacitor

A facile one-step mechanochemical process from CuCl₂·2H₂O and thiourea to fabricate novel [Cu(tu)]Cl·1/2H₂O nanobelts has been observed for the first time, and the nanobelts were used as an electrode material for a supercapacitor.

Polyvinylpyrrolidone (PVP) in nanoparticle synthesis

The versatile role of PVP in nanoparticle synthesis is discussed in this Perspective article.

Monodisperse CuS nanodisks: low-temperature solvothermal synthesis and enhanced photocatalytic activity

Controllable synthesis of uniformly disk-shaped CuS nanostructures with a narrow size distribution was realized by a low-temperature (150 °C) solvothermal process using polyvinyl pyrrolidone (PVP) as the surfactant.