Enhancement of the O2 Sensitivity: ZnO, CuO, and ZnO/CuO Hybrid Additives' Effect on Meso-Tetraphenylporphyrin Dye

Abstract

Semiconductor metal oxide materials have attracted great interest in gas sensors due to their high sensitivity to many target gases. In this study, an oxygen-sensitive optical chemical sensor was prepared in thin-film form by immobilizing meso-tetraphenylporphyrin (H2TPP) in silicon matrix in the presence of ZnO, CuO and ZnO/CuO hybrid nanoparticles as additives. Characterization of synthesized metal oxide powders was performed using XPS, XRD, SEM, and PL spectroscopy. Emission and decay time measurements of H2TPP-based materials were investigated between the concentration range of 0% and 100% [O2] in thin-film forms. The intensity-based signal drops of the additive-free form of porphyrin dye toward oxygen were calculated as 70%. Whereas, the oxygen sensitivities of H 2TPP-based sensor slides were measured as 80%, 75%, and 88% in the presence of ZnO, CuO, and ZnO/CuO hybrid particles, respectively. The usage of porphyrin dye with ZnO/CuO hybrid additive provided higher oxygen sensitivity, larger linear response range, higher Stern-Volmer constant (KSV) value and faster response time compared to the undoped form, ZnO and CuO additive-doped forms of H2TPP. The response and the recovery times of the porphyrin-based sensing slide along with ZnO/CuO hybrid particles have been measured as 10 and 20 s. These results make the H2TPP along with the metal oxide additives promising candidates as oxygen probes.

Enhanced luminescence of a silica‐nitride phosphor; La3Si6N11:Ce3+by using Cr3+‐activated TiO2 nanoparticles

“…Alternatively, the preparation of binary mixtures of the phosphors with the nanoscale light harvesting materials may exhibit promising spectral results. However, such kind of studies are rare and include the utilization of nanoscale hematite, iodine‐decorated hematite, 17 ZnO or CuO particles, 18 and silica photonic crystals, 19 in form of phosphor blends in optically transparent polymeric matrices. In this work, we intended to investigate the excitation–emission behavior of the binary blends of the La 3 Si 6 N 11 :Ce 3+ with the light harvesting materials of TiO 2 and Cr 3+ ‐doped TiO 2 nanoparticles (NPs) in a polymethylmethacrylate (PMMA) matrix.…”