One-step Synthesis of Ordered Pd@TiO₂ Nanofibers Array Film as Outstanding NH₃ Gas Sensor at Room Temperature

The one dimensional (1D) ordered porous Pd@TiO₂ nanofibers (NFs) array film have been fabricated via a facile one-step synthesis of the electrospinning approach. The Pd@TiO₂ NFs (PTND3) contained Pd (2.0 wt %) and C, N element (16.2 wt %) display high dispersion of Pd nanoparticles (NPs) on TiO₂ NFs. Adding Pd meshed with C, N element to TiO₂ based NFs might contribute to generation of Lewis acid sites and Brønsted acid sites, which have been recently shown to enhance NH₃ adsorption-desorption ability; Pd NPs could increase the quantity of adsorbed O₂ on the surface of TiO₂ based NFs, and accelerated the O₂ molecule-ion conversion rate, enhanced the ability of electron transmission. The response time of PTND3 sensor towards 100 ppm NH₃ is only 3 s at room temperature (RT). Meantime, the response and response time of the PTND3 to the NH₃ is 1 and 14s even at the concentration of 100 ppb. Therefore, the ordered Pd@TiO₂ NFs array NH₃ sensor display great potential for practical applications.