Development of Dual Z-Scheme Functionalized g-C₃N₄/CeO₂Bi₂S₃ (PCB) Heterojunctions Impregnated Hydrogels Towards Visible Light Assisted Ammonia Generation

Abstract

Biopolymer based photocatalysis has emerged as a sustainable alternative for the treatment of hazardous organic pollutant coupled with valuable product formation. This study reports the preparation of dual Z-scheme functionalized g-C N /CeO Bi S (PCB) heterojunctions embedded in sodium alginate hydrogels, designed as a photocatalysis for ammonia production. The comprehensive analyses of morphology, structure, crystallinity, optical properties, and chemical composition confirmed the successful construction of PCB hydrogels. Photocatalytic experiments demonstrated that ammonia was generated via a two-step dual-electron reduction pathway, reaching a maximum concentration of 1020 mM within 60 min under visible-light irradiation. Additionally, PCB hydrogels exhibited excellent reusability, maintaining performance over five cycles with only a 5% reduction in degradation efficiency. The dual Z-scheme heterojunction enhanced electron transfer, suppressed charge recombination, and accelerated ammonia production. Overall, this work provides valuable insights into the on-site utilization of ammonia for organic pollutant remediation using recyclable biopolymer-based photocatalysts.