Tungsten Oxide Morphology-Dependent Au/TiO2/WO3 Heterostructures with Applications in Heterogenous Photocatalysis and Surface-Enhanced Raman Spectroscopy

Developing highly efficient Au/TiO2/WO3 heterostructures with applications in heterogeneous photocatalysis (photocatalytic degradation) and surface-enhanced Raman spectroscopy (dye detection) is currently of paramount significance. were obtained via heat or time-assisted synthesis routes developed by slightly modifying the Turkevich–Frens methods investigated TEM, SEM, XRD, spectroscopy, XPS, photoluminescence, UV–vis DRS techniques. Structural features, such as WO3 crystalline phases, TiO2 surface defects, well (220) to TiO2-A (101) ratio, key parameters needed obtain enhanced photocatalytic activity for removing oxalic acid, phenol, methyl orange, aspirin. Photodegradation efficiencies 95.9 96.9% acid; above 96% (except one composite) phenol; 90.1 97.9% orange; 81.6 82.1% aspirin obtained. By employing SERS technique, detection limit crystal violet dye, depending on heterostructure, was found be between 10−7–10−8 M. The most promising composite Au/TiO2/WO3-HW-TA it yielded conversion rates 82.1, 96.8% aspirin, respectively, its 10−8 Au/TiO2/WO3-NWH-HA achieved 90.1, 96.6 99.0% degradation efficiency whereas 10−7 heterojunctions exhibited excellent stability substrates, yielding strong-intensity signals pollutant molecules even after a long period time.