Urchin-like Bi2S3 modified TiO2 for improved photocathodic protection of 304SS.

Severe charge recombination and poor light absorbance are the limiting factors for TiO 2 to access efficient photocathodic protection (PCP) towards metals. Engineering the TiO 2 with Bi 2 S 3 to form the heterojunction is proposed to overcome these limitations. Impressively, the optimal Bi 2 S 3 -12 h@TiO 2 photoanode coupled with 304SS displays an open circuit potential that negatively shifts to −480 mV vs Ag/AgCl, accompanied by a photoinduced current of 18.5μA/cm2. Comprehensively, characterizations discover that a tight interface between TiO 2 and Bi 2 S 3 exhibits strong electron interaction. The resulting enhanced PCP performance is attributed to extending the photoresponse range, increasing the carrier density, and improving the photocarrier separation. This work proves and validates the effectiveness of Bi 2 S 3 @TiO 2 in enhancing the PCP performance and provides the instruction to construct a high-performance photoanode. [Display omitted] • The tight interface between Bi 2 S 3 and TiO 2 is formed in the heterojunction. • The strong electron interaction between Bi 2 S 3 and TiO 2 favors the charge separation. • Light-harvesting properties are extended from ultraviolet to visible light. • The heterojunction effectively suppresses the photocarrier suppression. [ABSTRACT FROM AUTHOR]