Biomass-Printed Hybrid Solar Evaporator Derived from Bio-polluted Invasive Species, a Potential Step toward Carbon Neutrality

Biomass-based photothermal conversion is of great importance for solar energy utilization toward carbon neutrality. Herein, a hybrid solar evaporator is innovatively designed via UV-induced printing of pyrolyzed Kudzu biochar on hydrophilic cotton fabric (KB@CF) to integrate all parameters in a single evaporator, such as solar evaporation, salt collection, waste heat recovery for thermoelectricity, sieving oil emulsions, and water disinfection from microorganisms. The UV-induced printed fabric demon-strates stronger material adhesion as compared to the conventional dip-dry technique. The hybrid solar evaporator gives an enhanced evaporation rate (2.32 kg/m2 h), and the complementary waste heat recovery system generates maximum open-circuit voltage (Vout similar to 143.9 mV) and solar to vapor conversion efficiency (92%), excluding heat losses under one sun illumination. More importantly, 99.98% of photothermal-induced bacterial killing efficiency was achieved within 20 min under 1 kW m-2 using the hyperthermia effect of Kudzu biochar. Furthermore, numerical heat-transfer simulations were performed successfully to analyze the enhanced interfacial heat accumulation (75.3 degrees C) and heat flux distribution of the thermoelectric generators under one sun. We firmly believe that the safe use of bio-polluted invasive species in hybrid solar-driven evaporation systems eases the environmental pressure toward carbon neutrality.

Automated summary

In this study, a hybrid solar evaporator was designed by printing pyrolyzed Kudzu biochar on hydrophilic cotton fabric. The evaporator integrates multiple functions such as solar evaporation, salt collection, waste heat recovery, oil emulsion sieving, and water disinfection. The hybrid evaporator exhibited enhanced evaporation rate, high solar to vapor conversion efficiency, and efficient bacterial killing capability.