Halide-Tuned Preparation of BiPO ₄ /{110}BiOBr x I 1-x Nanocomposites for Improved Photocatalytic Degradation of Phenol

BiPO 4 /{110}BiOBr x I 1-x (x = 0, 0.25, 0.5, 0.75, 1) nanocomposites with p-n heterojunction structure, which predominantly expose the {110} facet, were successfully created using a straightforward solvothermal technique. Multiple techniques have been implemented to characterize and analyze the produced photocatalyst. The degradation of phenol was used to assess their photocatalytic effectiveness. The best performing sample was the 5%BiPO 4 /{110}BiOBr 0.75 I 0.25 nanocomposites, achieving complete decomposition of phenol within 60 minutes. Photocurrent measurements revealed that the enhanced performance is attributable to the creation of the heterojunction and the dominant {110} facet, which collectively suppress the recombination of photogenerated charge carriers. Furthermore, the heterojunctions’ optical absorption characteristics were tunable by varying the Br/I molar ratio. Superoxide radicals (·O 2 - ), holes (h + ), and hydroxyl radicals (·OH) were identified as the primary active species responsible for photocatalytic degradation via radical trapping experiments.