Fabrication of stable superhydrophobic bismuth material on the aluminum substrate with high photocatalytic activity

The bismuth superhydrophobic surface (BiSHS) was fabricated on aluminum (Al) substrate by immersion in BiCl₃ aqueous solution following annealing treatment. The surface morphology of the sample shows cauliflower and landmass like structures by scanning electron microscope. The size of NPs in the microscaled landmass texture is from 200 to 500 nm. The BiSHS contains the Bi/Bi₂O₃ layer on the top of Al/Al₂O₃ with static water contact of 160° ± 1° and a dynamic sliding angle of 2° ± 1°. The BiSHS exhibits excellent corrosion resistance, perfect environmental stability, and durability. The BiSHS has shown high photocatalytic activity in photodegradation of methylene blue with 98.17 % degradation efficiency. The photodegradation follows the pseudo-first-order kinetic reaction with a half-life period of 8.21 min. The photocatalytic capability of the BiSHS remained persistent even after the 11th cycles. The actual mechanism of BiSHS and wettability phenomena also elucidated according to the Wenzel and Cassie-Baxiture theories. This finding may open new windows for the utilization of superhydrophobic films as a photocatalyst. Graphical abstract: [Figure not available: see fulltext.]