Synthesis of α-MoO₃ nanoplates using organic aliphatic acids and investigation of sunlight enhanced photodegradation of organic dyes

Thermodynamically stable α-MoO₃ nanoplates were synthesized using organic aliphatic acids as structure controlling agents and investigated photocatalytic degradation of methylene blue (MB) and rhodamine blue (Rh-B) in presence of sun light. Three different organic aliphatic acids, citric acid (CA), tartaric acid (TA) and ethylene diamine tetra-acetic acid (EDTA), were employed to control morphologies. CA and TA predominantly produced extended hexagonal plates where EDTA gave nanorods as well as nanoplates. PXRD studies confirmed the formation of α-MoO₃ nanoparticles. HR-TEM and FE-SEM reveal the formation of plate morphologies with 20-40 nm thickness, 50-100 nm diameter and 600 nm lengths. The different morphologies of α-MoO₃ nanoparticles lead to the tunable optical band gap between 2.80 and 2.98 eV which was obtained from diffused reflectance spectra (DRS). Interestingly, the synthesized α-MoO₃ nanoplates exhibited strong photocatalytic degradation of MB and Rh-B up to 99% in presence of sun light without using any oxidizing agents.