Multifunctional bio-based photothermal hydrogel for highly efficient seawater desalination and contaminant adsorption
Mr. Bibek Chaw Pattnayak
National Institute of Technology, Rourkela
Ph.D. scholar
A vertically aligned porous photothermal PVA-psyllium husk hybrid hydrogel (PHH) has been prepared by introducing naturally abundant biomass psyllium husk (PH), along with nitrogen-doped carbon quantum dots-iron oxide hybrid nanocomposite (NCQD@Fe3O4) into polyvinyl alcohol hydrogel. Using PHH, an evaporation rate of 2.6 kg m−2 h−1 and ≈ 92% solar to vapor conversion efficiency have been achieved under 1 sun. After 10 cycling tests, PHH shows an evaporation rate of ⁓ 2.5–2.6 kg m−2 h−1 under different harsh conditions (pH 3–14 and salinity up to 250 g/kg), indicating long-lasting stability. In addition to this, the PHH evaporator shows excellent salt-resistant desalination and contaminant adsorption performance in seawater. Owing to a series of merits such as cost-effectiveness ($5.23/m2 ), high vapor conversion efficiency, excellent transport, and salt mitigation properties.