Near-Infrared Light-Responsively Controlled-Release Herbicide Using Biochar as a Photothermal Agent

In this work, near-infrared light (NIRL)-responsively controlled-release herbicide particles (NCHPs) were fabricated using biochar, attapulgite (ATP), NH4HCO3, ethylcellulose (EC), silicon oil (SO), and glyphosate (Gly). Gly and NH4HCO3 were adsorbed onto the ATP nanonetwork that distributed into biochar channels. The resulting complex was granulated and coated by EC and SO to form NCHP. Biochar acted as a photothermal agent, with a photothermal conversion efficiency of 38%, to convert light energy into thermal energy, thus triggering NH4HCO3 decomposition into CO2 and NH3 that broke through the coating and facilitated Gly release. Additionally, NCHP showed a higher control efficacy on weeds than Gly alone. Hence, this work provides results for a promising method to control the release of Gly, increase utilization efficiency, and decrease environmental contamination.