Influence of nanoscale defects on the improvement of photocatalytic activity of Ag/ZnO

This study presents the advances in field of ZnO/Ag catalysts from synthesis hierarchical ZnO nanowires (NWs) decorated with Ag nanoparticles, prepared by a facile solvothermal method at 120°C. It evaluates photocatalytic efficiency studying time reaction Ag/Zn concentration ratio and presence cetyltrimethylammonium bromide (CTAB) as an organic dispersant. X-ray diffraction, scanning electron microscopy, analytical/high-resolution transmission microscopy results confirmed homogeneous cylindrical quasi-spherical crystals. NWs exhibited hexagonal wurtzite structure cubic FCC symmetry nanoparticles (NPS). Two types nanostructures, including absence simultaneous NPs, formed depending on experimental conditions. The activity was evaluated methylene blue (MB) degradation under UV light excitation. Diffuse reflectance UV–Vis spectrophotometry (UV–Vis DRS) allowed identifying absorption band ~393 nm. Crystal size varied addition CTAB. Synthesis increased bandgap values, getting better performance samples synthesized intermediate times (6 h), higher Ag+/Zn2+ molar (0.2/1.0), According to HRTEM observations, silver nanocrystals high content defects (twinning, stacking faults) could play essential role response. In this context, specific conditions Ag/ZnO might be more appropriate for their use dyes water potential protective treatments against materials biodeterioration processes.