Alfalfa, peanut, and soybean plants take in nitrogen and hydrogen from the air and turn it into ammonia, which helps the plants grow. The reactions to produce ammonia are driven by natural catalysts, which lower the energy necessary to make the reactions happen. Inspired by these catalysts, scientists uncovered how sunlight can kick start the functionalization of nitrogen molecules. They built a complex that harvests sunlight. The added energy causes electrons to shift and makes the nitrogen molecules receptive to bonding with hydrogen and, thus, on the pathway to making ammonia.