Preparation of electron-withdrawing group phthalocyanine/bismuth halide oxides composite catalyst and its photocatalytic degradation of pollutants in water

To address the issue of poor carrier separation efficiency in pure bismuth iodide oxide (BiOI) photocatalysts, which results in suboptimal degradation performance of aquatic pollutants, this study prepared TNCoPc (TCCoPc)/BiOX composite semiconductor photocatalysts via a solvothermal method. Systematic characterization using XRD, UV–Vis DRS, radical scavenging experiments, and repeated stability tests revealed that the prepared TNCoPc/BiOI composite achieved degradation rates of 85.31 and 86.24% for RhB and OTC, respectively. Free radical scavenging experiments indicate that ·O 2− and h⁺ are the primary active species. The composite material constructs a Type II heterojunction, promoting the separation of photo-generated electron–hole pairs and enhancing photocatalytic efficiency. After five cycles of degradation testing, the composite material maintained degradation rates of 73.4 and 70.3%, demonstrating excellent structural stability and reusability. This study achieved synergistic enhancement of BiOI and photocatalytic performance through a simple yet effective composite strategy, offering new insights for designing highly efficient and stable visible-light-responsive materials for water pollution treatment. Graphical abstract