Ammonia photosynthesis under ambient conditions using an efficient nanostructured FeS2/CNT solar-energy-material with water feedstock and nitrogen gas

Through a facile solvothermal route, pyrite (FeS2) semiconductor nanoparticles were synthesized in the absence and presence of carbon nanotube (CNT), and employed as effective, narrow-bandgap, hole-scavenger-free, photocatalyst/solar-energy materials in a water photosplitting setup, to convert N-2 molecules into ammonia - a modern/green H-based fuel and agriculturally important chemical. The investigations revealed that the presence of CNT substantially enhances the photocatalyst activity. The superiority of FeS2/CNT nanocomposite energy material was explained in detail in terms of the ability of CNT to increase the photocatalyst surface area and interact with more N-2 molecules, boost the absorption of photons and effectually harvest the incident light, retard the recombination of e/h pairs, decrease the system impedance and facilitate the charge transfer process. Based on water-oxidation and proton reduction phenomena occurring upon the photocatalyst surface, the N-2-photofixation process was also interpreted from mechanistic/photoelectrochemical/energetic perspective.