Synergistic photocatalytic breakdown of azo dyes coupled with H₂ generation via Cr-doped α-Fe₂O₃ nanoparticles

This research addresses the scalable and inexpensive synthesis of α-Fe₂O₃via hydrothermal method without any precipitating agent as well as the enhancement of solar driven photocatalytic and H₂ production through doping different chromium proportions. Competency of α-Fe₂O₃, both pure and doped with chromium, to function as photocatalyst was evaluated by its interaction with multiple dyes, which was real-time monitored utilizing (Internet of Things) IoT technique. By adding chromium, the rate of deterioration increased substantially from 15 to 94% for TB under sunlight in a remarkably brief 20 min by employing a very small amount of Cr_0.8Fe_1.2O₃ (0.3 g/L), as evidenced by high degree of mineralization i.e. 85% and LC-HRMS. Also, the rapid breakdown of Trypan Blue (TB) was indicated by BOD₅/COD ratio. Moreover, Cr-doped α-Fe₂O₃ displays excellent H₂ production (~ 132 μmol h⁻¹ g⁻¹) as compared to α-Fe₂O₃. This work highlights the potential utilization of Cr-doped α-Fe₂O₃ for the purification of industrial waste water and green energy harvesting.