In-situ growth of MoS2 on 3D printed phosphorylated cellulose for simultaneous dye degradation and microbial inactivation

In this study, sustainable and eco-friendly route for production of 3D printable phosphorylated cellulose (PC) gel was developed using low-cost agro-based chemicals followed by in situ growth of MoS2 via hydrothermal treatment. The rheological studies show PC gel with incorporated salts exhibited shear-thinning behaviour with excellent 3D printability. The produced PC gel contains covalently modified phosphate groups with high surface charge, providing sites for electro-static interaction of salts and growth of MoS2, as confirmed by FTIR and XPS spectroscopy studies. XRD and Raman spectroscopy studies confirmed the high loading of MoS2 with mixed 2H/1 T phase and cellulose II structural transformation during hydrothermal treatment. Interestingly, the developed 3D-printed PC-based MoS2 structures show simultaneous photodegradation and microbial decontamination capabilities with high recyclability (similar to five times). The optimized PCMo0.5% exhibited efficient photodegradation (similar to 82-99%) of high concentration of methylene blue (MB) dye (50-500 mg/L) with maximum degradation capacity of 202.97 mg/g. The developed PCMo0.5% also showed a band gap of 1.30 eV and similar to 82.6% of DPPH scavenging activity. It also displayed a strong antibacterial response against Gram-positive Escherichia coli and Gram-negative Staphylococcus aureus with a distinct zone of inhibition. Most importantly, easily scalable 3D printable PC-based MoS2 structures demonstrated continuous mode photodegradation and microbial decontamination, making it promising for the potential remediation of real wastewater at large volumes for practical applications.