锌掺杂木质素基碳点对大豆生长和增产的影响OA

To expand the application potential of lignin in agriculture and explore its feasibility in promoting crop growth and increasing soybean yield,the novel zinc-doped lignin-based carbon dots(Zn-LCDs)were synthesized using the alkaline hydrothermal method.This method utilized the enzymatic hydrolysis of lignin that was obtained during biomass conversion as carbon source and substrate.Hydroponic experiments and foliar sprays were used to evaluate the effects of Zn-LCDs on soybean growth and yield.The material characterization results showed that the prepared Zn-LCDs had a quasi-spherical structure,with an average particle size of(4.88±0.60)nm,and good dispersion.Transmission electron microscopy(TEM),Raman spectroscopy(Raman)and Fourier transform infrared spectroscopy(FT-IR)analyses showed that Zn-LCDs were composed of highly graphitized carbon skeletons,and their surfaces were rich in carboxyl groups(—COOH),hydroxyl groups(—OH)and other active functional groups,which were conducive to enhancing their water solubility and plant cell penetration ability.X-ray photoelectron spectroscopy(XPS)further confirmed that Zn2+was successfully doped into the carbon dot structure,giving it additional biological activity.Ultraviolet absorption spectra and fluorescence emission spectra showed that Zn-LCDs had excellent light capture ability and fluorescence performance and could effectively respond to visible light excitation.The result of photocurrent experiments further revealed that the zinc-doped lignin-based carbon dots(Zn-LCDs)could significantly improve the current response of chloroplasts under light conditions,indicating that they played a positive role in the process of light energy absorption,transfer and electron transfer.This property may be closely related to the excellent light capture ability and fluorescence performance of Zn-LCDs,which can act as a"light bridge"or"electronic medium"in plant photosynthesis systems,assisting chloroplasts to convert light energy into chemical energy more efficiently.In the hydroponic experiments,different concentrations of Zn-LCDs showed that the treatment had a promoting effect on the growth of soybean seedlings,and the effect of 50 mg/L was the most significant.The subsequent field experiments further verified the application potential of Zn-LCDs:the yield per unit area(10 m2)of soybean applied with Zn-LCDs increased by 12.9％,the photosynthetic rate increased by 26％,and the activity of ribulose carboxylase diphosphate(Rubisco),a key photosynthetic enzyme,increased by 40％,which fully demonstrated that it had a significant effect on soybean growth and yield improvement under natural environmental conditions.This study combines lignin-based carbon dots with the concept of agricultural light fertilizer,which not only expands the high-value utilization path of lignin,but also provides a theoretical basis and technical support for the development of green,efficient and sustainable nano-light fertilizer.