Zeolites as Carriers of Nano-Fertilizers: From Structures and Principles to Prospects and Challenges

Abstract

The world is facing immense challenges in terms of food security, due to the combined impacts of the ever-increasing population and the adversity of climate change. In an attempt to counteract these factors, smart nutrient delivery systems, including nano-fertilizers, additives, and material coatings, have been introduced to increase food productivity to meet the growing food demand. Use of nanocarriers in agro-practices for sustainable farming contributes to achieving up to 75% nutrient delivery for a prolonged period to maintain nutrient availability in soil for plants in adverse soil conditions. In this context, sieve-like zeolites and the diversity in their structural morphologies have attracted increasing interest over recent years. Engineered nano-porous zeolites, also called aluminosilicates, are defined based on the presence of micro- (<2 nm), meso- (2–50 nm), and macropores (>50 nm), which can be employed as carriers of fertilizers due to their enhanced ion-exchange properties and adsorption capabilities. In this study, we provide a detailed overview of the production and optimization of hierarchical zeolite structures within the size range from micro- to nanometers, as well as the various top-down and bottom-up approaches which have been used to synthesize zeolites with a large surface area, tunable pore size, and high thermal stability, which make them an excellent candidate to be used in agronomy. The delivery of pesticides, insecticides, and fertilizers by loading them into nano-zeolites to manage the crop production without disrupting the soil health is discussed, as well as future perspectives of zeolites in the perpetual maintenance of soil productivity.