Ultrasound-Assisted Reverse Micelle Synthesis of ZnSe/ZnS Nanomaterials-Study of the Effect of Power and Water:Surfactant Ratio on Morphology and Crystallinity.

The controlled formation of coherent interfaces in lattice-mismatched II-VI semiconductor heterostructures remains challenging. In this work, ZnSe/ZnS laminar nanomaterials were synthesized by an ultrasound-assisted reverse micelle method to determine how ultrasonic power (150 and 200 W) and water-to-surfactant molar ratio (16:1, 32:1, and 48:1) jointly regulate morphology, crystal structure, lattice accommodation, optical response, and photoelectrochemical behavior. Higher ultrasonic power favored more clearly defined laminar morphologies, whereas increasing the water-to-surfactant ratio produced more heterogeneous growth domains. XRD and Raman spectroscopy confirmed the presence of zinc-blende ZnSe and ZnS phases and provided indirect evidence consistent with partial pseudomorphic lattice accommodation, with calculated mismatch values of 1.59-3.07%, compared with the theoretical value of 4.43%. The apparent optical band gap decreased from 3.39 to 3.06 eV at 200 W and from 3.34 to 3.04 eV at 150 W as the water content increased. Photochronoamperometry showed predominantly cathodic responses, whereas P1R1 exhibited an anodic response. These results establish ultrasonic power and micellar composition as coupled synthesis parameters for tuning lamellar growth, interfacial strain, and optoelectronic response in ZnSe/ZnS heterostructures.