Enhanced dual function of Ag nanoparticles decorated one-dimensional polymorphic TiO2 composites for sustainable environmental applications

The hydrothermally synthesized rutile-TiO₂ nanorods were spin-coated with anatase-TiO₂ film and decorated with Ag nanoparticles via sputtering to construct Ag nanoparticles decorated heterophase TiO₂ composites. By extending the sputtering duration to altering the Ag content in the TiO₂ composition, we aim to investigate the correlation between the microstructures and the dual function of photoelectrochemical photocatalytic and gas-sensing performances for environmental applications. The Ag nanoparticles on the anatase/rutile-TiO₂ composites facilitate photon absorption through surface plasmon resonance. Also, Ag nanoparticles contribute the hot electron to enhance the synergy effect in the anatase-TiO₂/rutile-TiO₂ to prevent recombination of photoinduced carriers under irradiation, thereby strengthening the photocatalytic characteristics. Furthermore, the gas sensing performance is improved due to the electronic and chemical sensitization effects caused by the Ag nanoparticles on the anatase-TiO₂/rutile-TiO₂ composite. This study demonstrates that tuning Ag nanoparticle content in the anatase/rutile-TiO₂ composites is a promising material design strategy for use in highly efficient photoexcited and gas-sensing devices. The proposed Ag nanoparticles decorated polymorphic TiO₂ composite nanorods are suitable for eliminating organic pollutants in water and ethanol pollution monitoring.