In this work, a facile oxidation strategy was developed to prepare novel tungsten disulfide/tungsten trioxide (WS₂/WO₃) heterostructures for adsorbing organic dyes efficiently by combining the hydrophilic property of WO₃ and the superior dye affinity of WS₂. The structural and elemental properties of the synthesized hybrid materials were systematically investigated, and the results demonstrated the retained flower-like morphology of the primitive WS₂ and the successful introduction of WO₃. Furthermore, surface properties such as a superior hydrophilicity and negative-charged potential were also demonstrated by a water contact angle characterization combined with a Zeta potential analysis. The performance of the obtained WS₂/WO₃ hybrid materials for removing Rhodamine B (RhB) from wastewater was evaluated. The results showed that the maximum adsorption capacity of the newly synthesized material could reach 237.1 mg/g. Besides, the adsorption isotherms were also simulated by a statistical physics monolayer model, which revealed the non-horizontal orientation of adsorbates and endothermic physical interaction. Finally, the adsorption mechanism and the recyclability revealed that the partial oxidation strategy could contribute to a higher adsorption capacity by modulating the surface properties and could be applied as a highly efficient strategy to design other transition metal dichalcogenides (TMDs) heterostructures for removing organic dyes from wastewater.

As the first step in the crystallization process, nucleation has been studied by many researchers. In this work, phenacetin (PHEN) was selected as a model compound to investigate the relationship between the solvent and nucleation kinetics. Induction times at different supersaturation in six solvents were measured. FTIR and NMR spectroscopy were employed to explore the solvent–solute interactions and the self-association properties in solution. Density functional theory (DFT) was adopted to evaluate the strength of solute–solvent interactions and the molecular conformations in different solvents. Based on these spectroscopy data, molecular simulation and nucleation kinetic results, a comprehensive understanding of the relationship between molecular structure, crystal structure, solution chemistry and nucleation dynamics is discussed. Both the solute–solvent interaction strength and the supramolecular structure formed by the self-association of solute molecules affect the nucleation rate. The findings reported here shed new light on the molecular mechanism of nucleation in solution.