In this study, we prepared high-nitrogen self-doped porous carbons (NPC1 and NPC2) derived from the pruned branches and seeds of Zanthoxylum bungeanum using a simple one-step method. NPC1 and NPC2 exhibited elevated nitrogen contents of 3.56% and 4.22%, respectively, along with rich porous structures, high specific surface areas of 1492.9 and 1712.7 m² g⁻¹ and abundant surface groups. Notably, both NPC1 and NPC2 demonstrated remarkable adsorption abilities for the pollutant methylene blue (MB), with maximum monolayer adsorption capacities of 568.18 and 581.40 mg g⁻¹, respectively. The adsorption kinetics followed the pseudo-second-order kinetics and the adsorption isotherms conformed to the Langmuir isotherm model. The adsorption mechanism primarily relied on the hierarchical pore structures of NPC1 and NPC2 and their diverse strong interactions with MB molecules. This study offers a new approach for the cost-effective design of nitrogen self-doped porous carbons, facilitating the efficient removal of MB from wastewater.

Food industry wastewater containing synthetic dyes threatens ecological safety and human health. Therefore, efficient and environmentally friendly adsorbents that can remove synthetic food dyes from wastewater are urgently needed. In this work, a self-nitrogen-doped biochar (GSNBC), used for adsorption of food dyes including carmine and tartrazine, was facilely prepared by employing ginger straw waste as the carbon precursor and NaHCO₃ as a mild and relatively benign pore-forming agent via one-step pyrolysis. The as-prepared GSNBC featured well-developed porous structures, a specific surface area of 1712.52 m² g⁻¹, and rich oxygen- and nitrogen-containing functional surface groups. Particularly, GSNBC performed ultrafast adsorption, with approximately 90% of the equilibrium capacity within 1 min (600.13 mg g⁻¹ and 580.24 mg g⁻¹ for carmine and tartrazine, respectively), and reached adsorption equilibrium at about 10 min. In addition, it exhibited excellent regenerability. The adsorption kinetics and isotherms fit well with pseudo-second-order and Langmuir models. DFT calculations indicated that π–π stacking and hydrogen bonding were mainly responsible for the adsorption. This study presents not only a promising and efficient adsorbent for the remediation of dye-laden food industry wastewater but also a sustainable route for the resource utilization of ginger straw waste.

Soil-borne pathogens significantly threaten crop production and global food security, while high-performance antipathogenic materials are scarce. In this study, green and efficient Ag/AgCl nanoparticles (Ag/AgCl-NPs) were developed using an aqueous extract of ginger-straw waste as the raw material. The synthesized Ag/AgCl-NPs exhibited a spherical morphology with an average size of approximately 40 nm, good crystal structure, and abundant surface groups. Additionally, they exhibited excellent antimicrobial activity against representative soil-borne pathogens, including Ralstonia solanacearum (MIC = 20 μg/mL; MBC = 40 μg/mL) and Fusarium oxysporum (spore MIC = 20 μg/mL; mycelial EC₅₀ = 64.596 μg/mL). The antimicrobial mechanism was attributed to cell membrane disruption and oxidative stress induction. This study provides an excellent antimicrobial agent for controlling crop soil-borne pathogens.