Improving and exploring the photocatalytic performance of composites for new models continues to pose a challenge. Here, a straightforward thermal dispersion method is achieved by incorporating nitrogen (N) into TiO2 at different weights (1%, 3%, and 5%) to enhance photocatalytic activity. The material properties are analyzed through ultraviolet-visible diffuse reflectance spectroscopy (UV-VIS DRS), and X-ray diffraction (XRD). The results indicate that the NO gas removal efficiency of N-TiO2 photocatalytic materials is higher than that of pure TiO2 after 30 minutes of exposure to visible light. The highest NO gas treatment efficiency of N-TiO2 -1% is 40.4%, with a reaction rate following a first-order kinetic equation of 0.0688 min-1. Successfully fabricating N-TiO2 photocatalytic materials using the thermal dispersion method, with significantly enhanced photocatalytic performance under visible light activation, will benefit practical applications, particularly in the environmental sector.

Diatomite from Tuy An district, Phu Yen province, with different purities and diatom integrity as catalyst carriers, were adopted to prepare TNTs/g-C3N4 composite catalysts by a sol-gel method, with an optimal weight ratio of 1:1 for TNTs/g-C3N4 and diatomite. Compared with pure TNTs, g-C3N4, and TNTs/g-C3N4, the obtained composite photocatalysts exhibited lower photocatalytic performance under the same conditions and NO removal within 30 min under visible light. The NO gas treatment efficiency under the same conditions with different catalyst supports only decreases by approximately 18% at a reaction rate of 0.0950 min-1. This research on composite photocatalysts is a promising step towards practical environmental remediation. The use of diatomite as a carrier for photocatalytic materials is particularly noteworthy, as it is a naturally available and cost-effective source of materials. However, further improvements in the photocatalytic performance of the composite material are necessary to fully realize its potential in environmental remediation, including removing NOx and other pollutants. Overall, this study provides valuable insights into the influence of carriers on the photocatalytic activity of composite photocatalysts and lays the foundation for future research in this field.