In this work, we investigated the impacts of atmospheric pressure dielectric barrier discharge (DBD), i.e., plasma treatment, on pearl millet seeds germination and plant growth. The effect of plasma ...discharge on water activation, by introducing the reactive species, was explored. We evidenced that about 30 min plasma treated pearl millet seeds exhibited 20% higher germination rate than the control seed watered with tap water. The HR-SEM study revealed that the plasma treatment increased the roughness and FTIR study showed that new oxygen functional groups were introduced on the seed surface. Moreover, it was observed that the water contact angle decreased for plasma treated seeds (50%) and the water uptake also increased considerably as compared to control seeds. These findings indicate that the seed surface has turned more hydrophilic after plasma treatment. A cylindrical double dielectric barrier discharge (D-DBD) reactor was employed for water activation, and 30 min of treatment under air has decreased the pH of deionized water from 7.4 to 4.5 and produced about 1.78 ppm of nitrate (NO
3
−
) and 4.2 ppm of hydrogen peroxide (H
2
O
2
). Interestingly, the plasma activated water (PAW) improved the pearl millet seed germination by 30% (after 24 h of sowing) and plant growth as compared to tap water and deionized water. Remarkably, when PAW and plasma-treated seeds were combined, a beneficial impact in seed germination (95 ± 2%) and seedling growth have been evidenced owing to synergistic effect. We evidenced that among the long-lived species in PAW, NO
3
−
enhanced the seed germination and plant growth under similar conditions. These findings demonstrate that the proposed cold plasma reactors could be utilized to boost seed germination and plant growth.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 4 Given name: Amine Aymen Last name Assadi. Also, kindly confirm the details in the metadata are correct.Yes, all author names are correctly editted.
Display omitted
•A 30-min plasma treatment at 200 °C induced the formation of crystalline particles of inverse spinel CoFe2O4, a phenomenon not observed in samples without plasma treatment.•Plasma ...treatment at 200 °C, a significant reduction in particle size was observed, with the average size plummeting to 6.7 nm, nearly three times smaller than the calcined sample at 600 °C (24.1 nm).•The plasma assisted synthesized material displayed remarkable magnetic properties, boasting a magnetization (Ms) of 91.80 emu/g and a coercivity (Hc) of 888 Oe. In stark contrast, the material calcined at 600 °C exhibited a lower magnetization of 64.53 emu/g and a higher coercivity of 1289 Oe.•EDX analysis unveiled surface oxygen defects in plasma synthesized material compared to materials synthesized by conventional calcination at 600 °C, resulting in a narrower bandgap (1.9 eV).•XPS analysis unveiled the presence of Co2+ and Co3+ within the spinel crystal structure of the plasma-treated material, elucidating the mechanisms underlying its enhanced magnetic behavior.
Non-thermal plasma (NTP)-assisted catalysis offers a promising avenue with diverse applications, particularly in air and water treatment. This study aimed to investigate the utilization of NTP discharge for the synthesis of magnetically active nanoparticles (MANps). We have demonstrated that the NTP discharge-assisted low-temperature calcination effectively induces surface modification and crystallization, thereby enhancing magnetic susceptibility. Specifically, a 30 min plasma treatment at 200 °C (CF-P-200) facilitated the formation of crystalline particles, a phenomenon that was absent in materials synthesized without plasma treatment under similar operating conditions. High-resolution microscopy revealed an average particle size of about 6.7 nm, while EDX analysis unveiled surface oxygen defects in CF-P-200 compared to materials synthesized by conventional calcination at 600 °C (CF-T-600), resulting in a narrower bandgap (1.9 eV). Magnetization measurements conducted using vibrating sample magnetometry (VSM) displayed superior magnetic properties of plasma treated MANps, with a magnetization (Ms) of 91.80 emu/g and coercivity (Hc) of 888 Oe. These values outperformed those of materials calcined at 600 °C (Ms: 64.53 emu/g, Hc: 1289 Oe), emphasizing the efficacy of NTP discharge in enhancing magnetic characteristics during material synthesis.
