Earth-abundant catalyst for modification of wheat straw to enhance ammonia mitigation from fertilized alkaline soil

In this study, inexpensive earth-abundant catalyst of Co/TiO₂ is coupled with a low-temperature modification approach to enhance NH₃ adsorption capacity on wheat straw (WS). The highest NH₃ uptake achieved is 111.9 mg/g, with 80.8 % retention even after 3 h of desorption. Mechanistic investigation indicates that the enhanced adsorption capacity stems from Co/TiO₂, which facilitates generation of reactive oxygen species, leading improved ultra-micropore structure that enhances the interaction between NH₃ and oxygen-containing functional groups through a trapping effect. The robust stability of adsorbed NH₃ is attributed to the formation of amides or amines. Incorporation of only 1 wt% WS-Co to urea-fertilized alkaline soil reduced NH₃ volatilization by 83.1 %. The significant effect is primarily attributed to the excellent adsorption capacity of WS-Co, rather than alterations in the relative abundance of the microbial community. These findings present a novel approach for development of effective fertiliser additive to mitigate NH₃ volatilization from alkaline soil.