This study deals with a dual Z-scheme functionalized g-C3N4/CeO2/Bi2S3 (PCB) heterojunction impregnated with sodium alginate hydrogels have been prepared as photocatalysis-self-Fenton system to investigate the degradation of tetracycline without the need for additional H2O2. The morphological, structural, crystal, optical, and chemical compositions affirmed the construction of g-C3N4/CeO2/Bi2S3 (PCB) hydrogels. Photocatalytic investigations revealed that H2O2 production via a two-step dual-electron reduction pathway achieved the maximum H2O2 production of 1.4 mM within 60 min under the visible light irradiation. Tetracycline degradation efficacy increased to 81 % in 60 min via photocatalysis self-Fenton reaction. Moreover, g-C3N4/CeO2/Bi2S3 (PCB) hydrogels demonstrated a notable reusability up to 5 cycles with a decline of only 5 % in degradation efficiency. Furthermore, g-C3N4/CeO2/Bi2S3 (PCB) heterojunction hydrogels exhibited dual Z-scheme with enhanced electron transfer efficiency, reduced recombination rates, and accelerated H2O2 production. This research offers valuable insights into the on-site H2O2 utilization for the remediation of organic pollutants using recyclable biopolymer-based photocatalysts.