Glyphosate Is Converted into Energy in a Microfluidic Fuel Cell Equipped with a Low-Content Ni Anode and a Metal-Free Cathode

Abstract

Glyphosate, a widely used herbicide, poses significant environmental and health risks due to its persistence and potential toxicity. Existing mitigation methods often face challenges such as incomplete degradation or the generation of harmful byproducts, in addition to consuming energy to operate. Herein, we report the first demonstration of glyphosate being directly used as a fuel in a microfluidic fuel cell (μFC), enabling simultaneous energy generation and pollutant degradation. The μFC features a nickel-sputtered carbon paper (Ni/CP) anode and a metal-free carbon paper (CP) cathode. The sputtering process ensures the formation of well-dispersed, high-purity Ni nanoclusters, enhancing surface activity and catalytic performance with ultralow metal loading. Coupled with hypochlorous acid (HClO) reduction on the cathode, the μFC achieved a maximum power density of 0.18 mW cm-2 and glyphosate conversion efficiencies exceeding 99% for diluted solutions (16.2 ppm) and 82% for concentrated solutions (29.6 ppm). High-performance liquid chromatography confirmed the degradation of glyphosate to levels below the World Health Organization’s recommended limit of 0.9 mg L-1. Although additional research on the product of the μFC is necessary, this report on a membraneless μFC utilizing glyphosate as the sole energy source in a mixed-media environment shows energy recovery from an environmental pollutant under zero-bias conditions. This scalable, cost-effective system highlights the potential of integrating advanced nanostructured materials and electrochemical techniques for simultaneous pollutant removal and sustainable energy production.