Recent updates on Ag2WO4-based S-scheme heterojunction photocatalytic materials for environmental remediation

[Display omitted] •Structural properties of Ag2WO4 photocatalyst were discussed.•Various synthesis routes of Ag2WO4 were illustrated briefly.•Z-scheme and S-scheme heterojunctions as modification strategies were exemplified.•Experimental validation techniques were discussed for Ag2WO4-based Z and S scheme heterojunctions.•Ag2WO4-based Z/S scheme heterojunction were explored for pollutants degradation. Silver tungstate (Ag2WO4) as a captivating visible light active photocatalyst, is non-toxic in nature, chemically stable and possess good thermal stability. Extensive researcheshave lately centred on Ag2WO4 photoactivity for wastewater treatment. However, bare Ag2WO4 photocatalyst always showed low adsorption and high recombinant rate which inhibited its proficiency to work as a photocatalyst. So, recently, many advancement strategies have been introduced to overcome these difficulties such as doping, surface modification, conventional heterojunction, Z-scheme, and S-scheme heterojunction. But, in recent times, modern strategies including Z-scheme and S-scheme have attained typical consideration due to improved charge migration, and excellent light capture capability as well as longer the spatial life time of photocarriers while keeping the appropriate redox capability. So, this review offers an overview of current state-of-the-art in Ag2WO4-based heterojunctions and providing the insightful comments on the fabrication of these heterostructures. This review primarily focuses on structural and electronic properties via theoretical studies (DFT studies) as well as various synthesis methods to construct heterojunction of Ag2WO4. Also, exploration of different experimental approaches was done which provide confirmation for the operation of photocarriers migration between Ag2WO4 with another component. In addition, instances demonstrating the enhanced efficiency of Ag2WO4-based Z-scheme and S-scheme heterojunctions for several crucial photocatalytic processes includes dye colourization, antibiotic deterioration, heavy metal ions reduction, and bacterial disinfection. Designing rational Ag2WO4 heterojunction with small size particles and controlled morphology for suitable interfacial contact has received especial attention. Finally, the shortcomings of current research on Ag2WO4 based heterojunction photocatalysts are reviewed and prospected.