This study investigates the impact of nitrogen doping concentration on the photocatalytic activity of TiO2 catalysts. TiO2 thin film samples with varying nitrogen doping levels were synthesized using radio frequency magnetron sputtering on fused quartz substrates. Comprehensive characterization techniques were utilized to analyze the crystal structure, morphology, nitrogen doping status, light absorption properties, and photocatalytic performance of these samples. Additionally, first-principles simulations were performed to examine the crystal structure, electronic structure, and density of states of TiO2 across different nitrogen doping concentrations, aiming to clarify the underlying mechanisms affecting photocatalytic activity. The combined theoretical and experimental results reveal that nitrogen doping causes structural distortions in TiO2, transitioning it from an indirect to a direct bandgap semiconductor and reducing the bandgap width. This alteration enhances the photocatalytic efficiency of TiO2 thin films. Notably, the sample with 1.76% nitrogen doping demonstrated a photocatalytic efficiency of 58.95%, which is 2.08 times greater than that of undoped TiO2 thin films.
Gyroscope is a sensor that measures angular velocity, which is widely used in precision guidance, deep-sea operations, unmanned driving, etc. Currently, the gyroscope is moving towards the trend of compactness, high accuracy, high reliability and low cost, and the resonance integrated optical gyroscope is expected to be a preferred choice for the next generation of optical gyroscopes. In this paper, the finite element method is used for modeling and numerical simulation of silicon-based optical waveguide micro-ring resonator, a sensitive unit of resonant integrated optical gyroscope, in two-dimensional and three-dimensional, to research the effect of structural parameters of the resonator on its performance. Simulation results show that the free spectral width of the Si-based optical waveguide micro-ring decreases with increasing radius. The resonant depth of the micro-ring increases with the coupling spacing in a certain range, but it decreases with the coupling spacing beyond the critical coupling. In addition, the quality factor of the micro-ring resonator increases with the increase of radius. The research in this paper lays the foundation for performance optimization of the resonator.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.