Abstract:

In order to achieve higher degradation efficiency， it is indispensable to use photocatalysts in the field of wastewater treatment. Researching and preparing bismuth-modified TiO₂ photocatalysts （Bi-TiO₂ photocatalysts） and analyzing their photocatalytic performance are essential. Bismuth-based material and TiO₂ solution were separately prepared， and by mixing the two substances， the bismuth-modified TiO₂ photocatalyst was obtained. Using methyl orange as the test model solution， the catalytic performance of this photocatalyst at different ratios of bismuth-based material to TiO₂， different temperature conditions， light conditions， and photocatalytic durations was tested to verify the impact of methyl orange solution concentration and pH value on the photocatalytic effect. Experimental results showed that when the mass ratio of bismuth-based material to TiO₂ was 1∶1， the photocatalyst exhibited the best degradation and decolorization effects， demonstrating excellent photocatalytic performance. The Bi-TiO₂ photocatalyst exhibited varying degrees of methyl orange degradation ability， with the degradation rate initially increasing and then decreasing with the change in the ratio of bismuth-based material to TiO₂. The optimal photocatalytic performance of this catalyst was observed at a temperature of 45 ℃ and under 15 h of light exposure. When the temperature exceeded 120 ℃， the photocatalytic effect of the catalyst tended to stabilize. The photocatalytic performance was more ideal at a methyl orange mass concentration of 20 mg/L and a pH value of 4. Environmental concentration had minimal impact on the photocatalytic performance of the Bi-TiO₂ photocatalyst. Regardless of the variation in methyl orange mass concentration， the catalyst exhibited strong photocatalytic effects， with the best decolorization effect observed at a methyl orange mass concentration of 20 mg/L. The catalyst showed the highest methyl orange decolorization rate at a pH value of 4. Therefore， it is evident that the introduction of bismuth significantly enhances the photocatalytic performance and visible light responsiveness of TiO₂.

Key words: Bismuth-based materials, Modified TiO₂, Photocatalytic performance, Methyl orange