modification of bismuth oxyhalide photocatalysts with natural chlorophyll for enhanced photocatalytic performance.

Bismuth oxyhalides (BiOX) exhibit limited sunlight absorption and utilization, presenting a challenge for their effectiveness in photocatalytic applications. This study draws inspiration from the sensitization effects of natural chlorophyll on semiconductor photocatalysts, achieving synthesis of chlorophyll-sensitized BiOX photocatalysts through a precipitation method. The photocatalytic activity of these materials was evaluated under blue light irradiation (410-420 nm LED) using Rhodamine B (RhB) as a model pollutant. Experimental results reveal that chlorophyll derived from effectively sensitized BiOX samples, changed them specific surface area, and surface potential, thereby enhancing RhB degradation efficiency. Among the as-prepared BiOX materials, BiOBr demonstrated the most pronounced improvement, achieving a 97.8% degradation rate for 20 mg per L RhB within 90 min after sensitization. Mechanistic investigations through free radical trapping experiments identified superoxide radicals (˙O ), photogenerated electrons (e) and holes (h) as the key reactive species driving RhB degradation. This study underscores the critical role of chlorophyll sensitization in improving the photocatalytic efficiency of BiOX and provides a comparative analysis of the photocatalytic performance of BiOCl, BiOBr, and BiOI. The findings offer valuable perspectives for the advancement and practical implementation of sensitized photocatalysts in environmental remediation.