Constructing F-TiO2/Bi2S3 nanoflower heterojunction to improve charge separation for efficient organic pollutant degradation

The design and synthesis of TiO₂-based heterostructures using appropriate modifiers or semiconductor sulfides represents a promising strategy for further investigation. In this study, F is introduced into TiO₂, followed by the addition of Bi₂S₃ to construct F-TiO₂/Bi₂S₃ nanoflower heterojunction. The photocatalytic activity of the prepared catalysts is evaluated. At a MO concentration of 10 mg/L and catalyst concentration of 0.5 g/L, the TBS-3 composite photocatalyst exhibited a remarkable catalytic ability (0.1006 min⁻¹), removing 94.7 % of MO within 30 min, which was 25 and 5 times higher than that of Bi₂S₃ (0.004 min⁻¹) and F-TiO₂ (0.0216 min⁻¹) catalysts, respectively. The impact of initial solution pH, inorganic anion, catalyst dosage, and initial MO concentration on the degradation process are examined. The results of the free radical burst experiments indicate that the primary active species involved in the MO degradation process are superoxide radical anion (•O₂⁻). This work provides a reference for the design of efficient photocatalysts for water source protection and environmental treatment.