Tri-functional MFO nanoparticles for photocatalytic complex dye removal, salt-resistive ISSG membrane, and hydrovoltaic electricity generation

Abstract

Addressing global water scarcity and pollution requires the development of innovative, multifunctional materials capable of simultaneously tackling multiple challenges. This study explores manganese ferrite (MnFeO3, MFO) nanoparticles synthesized via a co-precipitation method for their tri-functional performance in environmental remediation, clean water production, and energy generation. The MFO catalyst exhibits robust photocatalytic activity, achieving 98.99 % degradation of crystal violet (CV) dye and demonstrating efficacy against both cationic and anionic dyes. Furthermore, MFO-coated cellulose-based devices enable efficient interfacial solar steam generation (ISSG) from saline water of varying concentrations, indicating potential for clean water production. The MFO photothermal evaporator generated 47.6 °C temperature at the air/water interface and achieved evaporation rates of 2.28 kg/m2h under solar simulator and 1.6 kg/m2h under direct sunlight. Evaporation rates of ∼1.89, ∼1.58, and ∼1.40 kg/m2h were obtained from 3.5, 7.0, and 10 wt % saline water, respectively. The MFO@cellulose evaporator maintained a surface temperature of ∼65 °C in ambient air and exhibited stable rejection performance over 5 ISSG cycles for 3.5 wt % salt water. Beyond water remediation, MFO also demonstrates potential in hydro-voltaic electricity generation, producing an open-circuit voltage of 0.7 V for 10 devices connected in series through electro-kinetic processes under natural sunlight. This integrated approach underscores the versatility of MFO and presents a promising route for sustainable water treatment and renewable energy generation, particularly suitable for deployment in resource-limited surroundings. © 2025 Elsevier B.V.