4th International Eurasian Conference on Science, Engineering and Technology (EurasianSciEnTech 2022), Ankara, Türkiye, 14 Aralık 2022
Accurate, continuous and precise monitoring of dissolved and gaseous carbondioxide
(CO2) is vital in industrial, chemical, medical and atmospheric
analysis. In this study, SnO2 and Ni-doped SnO2 powders
were added as additives to increase gas sensitivity to
8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) dye, which is a commercial
fluorescent indicator with high sensitivity to CO2 gas.
Characterizations of synthesized metal oxide semiconductors (MOSs) were
performed using photoluminescence spectroscopy (PL), X-ray photoelectron
spectroscopy (XPS), X-ray diffraction spectroscopy (XRD) and scanning electron
microscope (SEM). HPTS-based thin films were prepared by immobilizing dye and
MOSs additives to ethyl cellulose (EC) matrix. Steady-state measurements, decay
time kinetics and kinetic measurements of the sensor agents were measured in
the concentration range of 0-100% [CO2]. The addition of SnO2-based
semiconductors to the HPTS-based composites has resulted in many improvements in
sensor dynamics such as higher sensitivity, relative signal variation and
larger linear response range according to the additive-free form. The CO2
sensitivities of HPTS dye were measured as 4.7, 12.6 and 57.5 fold for the
undoped and SnO2 and Ni-doped SnO2 doped forms,
respectively. The response and recovery times of the HPTS-based sensing slide
against CO2 with Ni-doped SnO2 powders were measured as 38
and 156 s. These results make the HPTS fluorophore with SnO2 and Ni-doped SnO2
additives into more advanced sensor agents for sensitivity to CO2
gas and show it as a promising candidate for CO2 probes.