Organic semiconductor poly-2,6-diaminoanthraquinone composite and Bi loading synergistically enhance the photoelectrochemical cathodic protection performance of BiVO4

BiVO 4 -based materials have attracted extensive research as advanced photoanode for photogenerated cathodic protection. However, the performance of BiVO 4 -based photoanodes is greatly hindered by its weak charge migration and positive conduction band potential. Herein, poly-2,6-diaminoanthraquinone (PDAAQ)/Bi was grafted on BiVO 4 to improve the separation efficiency of photogenerated carriers and enhance the reducing ability of photogenerated electrons. Studies show that a type II heterojunction can be formed between PDAAQ and BiVO 4 , which accelerates the separation of photogenerated carriers at the interface. In addition, the Bi monomers anchored on BiVO 4 /PDAAQ then expand the light absorption range through the surface plasmon resonance effect. Consequently, the obtained BiVO 4 /PDAAQ/Bi photoanode exhibits a promising photocurrent density of 40 μA·cm -2 , while the photoinduced potential drop is 540 mV, which is approximately 1.4 times of BiVO 4 materials. These outcomes provide general ideas for the design of organic-inorganic heterozygous systems for achieving eco-friendly corrosion protection.