Laser-Ablated Transmutation of Bulk TiO₂ into Nanospheres onto a Clad-Polished Optical Fiber for Room-Temperature Gas Sensing

Abstract

The impact of environmental pollution on climate change has necessitated the development of highly efficient gas sensors. Among the various sensing materials, metal oxides have shown great potential for gas sensing applications. However, the quest for highly efficient room-temperature gas sensors is ongoing. In this study, we present an approach for the fabrication of nanospheres from bulk TiO2 using the template-free pulsed laser ablation technique in liquids. The obtained nanoparticles were comprehensively characterized using X-ray diffraction, Raman analysis, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible (UV–vis) spectroscopy, and photoluminescence (PL) studies to evaluate their structural, morphological, and optical properties. The room-temperature gas sensing performance of the fabricated TiO2 nanospheres (NTO) was evaluated using clad-modified fiber optic gas sensors for various gas concentrations. Remarkably, the NTO gas sensor exhibited interesting results, where the performance of NTO was twice that of its bulk counterpart, indicating its suitability for highly efficient gas sensing applications. Additionally, a theoretical calculation of light modulation through optical fibers was presented, providing insights into the sensing mechanism. Our findings demonstrate the potential of pulsed laser ablation in liquids for developing highly efficient room-temperature gas sensors for environmental monitoring applications.