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 demonstrates 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 ∼ 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 °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.

Lead-Free Bi3.15Nd0.85Ti3O12 Nanoplates Filler-Elastomeric Polymer Composite Films for Flexible Piezoelectric Energy Harvesting.

Nowadays, wearable and flexible nanogenerators are of great importance for portable personal electronics. A flexible piezoelectric energy harvester (f-PEH) based on Bi3.15Nd0.85Ti3O12 single crystalline nanoplates (BNdT NPs) and polydimethylsiloxane (PDMS) elastomeric polymer was fabricated, and high piezoelectric energy harvesting performance was achieved. The piezoelectric output performance is highly dependent on the mass ratio of the BNdT NPs in the PDMS matrix. The as-prepared f-PEH with 12.5 wt% BNdT NPs presents the highest output voltage of 10 V, a peak-peak short-circuit current of 1 µA, and a power of 1.92 µW under tapping mode of 6.5 N at 2.7 Hz, which can light up four commercial light emitting diodes without the energy storage process. The f-PEHs can be used to harvest daily life energy and generate a voltage of 2-6 V in harvesting the mechanical energy of mouse clicking or foot stepping. These results demonstrate the potential application of the lead-free BNdT NPs based f-PEHs in powering wearable electronics.