Good Vibrations: Harvesting Ammonia Through Simple Friction

The quest for carbon neutrality often hinges on how we produce ammonia, the backbone of global agriculture. Traditionally an energy-hungry endeavour, nitrogen fixation may soon rely on a force as mundane as it is ubiquitous: friction. Researchers have demonstrated a highly efficient method for pulling nitrogen directly from the air using bismuth sulphide (Bi₂S₃) particles driven by mechanical agitation.

In a clever application of 'tribocatalysis'—where the triboelectric effect meets electrochemistry—the team utilised a rotary disk made of polytetrafluoroethylene (PTFE) to stir bismuth sulphide particles. This simple mechanical action generates active radical negative charges, which are indispensable for converting atmospheric nitrogen into ammonia. Remarkably, this process requires neither light nor external heat. Operating in total darkness at room temperature, the system achieved ammonia generation rates of over 250 μmol L^-1 g^-1 h^-1 when aided by a solution containing 10% methanol.

The implications for sustainable development are profound. Bismuth sulphide is both abundant and non-toxic, making it an attractive candidate for widespread application. Furthermore, the catalyst proved robust, maintaining excellent performance after multiple cycles. By harnessing the wasted mechanical energy that surrounds us, this method presents a promising, environmentally friendly path towards decentralised ammonia production.