ABSTRACT The Type II heterojunction, characterized by its favorable band alignment, facilitated efficient charge separation in photocatalysts. Concurrently, oxygen vacancies can enhance light absorption and activated reactants, thereby improving photocatalytic efficiency. This study presented the synthesis of Bi‐TCPP/Bi 2 S 3 heterojunction photocatalysts, which were rich in oxygen vacancies, using a green, one‐pot method. The composite exhibited superior photoelectrochemical and photocatalytic reduction properties, achieving a rate constant of 0.03829 min −1 for Cr(VI) reduction and a remarkable reduction rate of 95.73%. After five cycles, the photocatalytic activity remained above 91.30%, demonstrating excellent stability and efficiency in reducing persistent pollutants. This work introduced a novel strategy for photocatalyst design and made a significant contribution to the fields of environmental remediation and green chemistry.