Photothermal effectiveness of microporous carbon nanospheres incorporated with polysulfone in direct contact membrane distillation

Abstract

Carbon nano-spheres (CNS) were synthesized via a hydrothermal method using D-glucose as a precursor, followed by pyrolysis in a nitrogen atmosphere. The resulting CNS were integrated into polysulfone (PSF) membranes to enhance their photothermal properties. Characterization using various techniques revealed improved thermal properties upon CNS inclusion, with a notable increase in membrane surface temperature and enhancement of contact angle (CA) and liquid entry pressure (LEP). Composite PSF membranes containing varying CNS concentrations (0.25–5%) exhibited optimal performance at 3% CNS concentration, demonstrating enhanced morphological conformation and photothermal attributes. Evaluation under tungsten bulbs light using a photothermal membrane distillation system showed significant improvement in membrane distillation flux, achieving a maximum water flux of 7.73 L m⁻² h⁻¹ and a salt rejection rate of 99.9%. These findings highlight the potential of hydrothermal CNS in enhancing photothermal properties and membrane performance for applications in desalination and wastewater treatment.