Effect of chelation in alkoxide precursors of niobium oxide nanoparticles on photochemical degradation of rhodamine B

In order to control the high moisture sensitivity, niobium ethoxide and niobium butoxide were chelated by bidentate ligands chloroacetic acid and dichloroacetic acid, in 1:1 and 1:2 molar ratios using dry toluene as a solvent. When these parent and tailored niobium alkoxides were subjected to hydrolysis followed by condensation and other sol–gel processing, they acted as precursors to yield nano-scaled niobium oxide particles. These chelated alkoxides and synthesized nanoparticles were characterized by various spectroscopic techniques. The synthesized niobium oxide nanoparticles are a promising choice to be used as photocatalyst under UV-VIS radiation to remove organic pollutants from water because of suitable band gaps. The band gaps of the synthesized nanoparticles were calculated by using Tauc plot. The photocatalytic efficiency of these nanoparticles was investigated over the degradation of common organic textile dye—Rhodamine B, under photochemical conditions. The optimization of various conditions like catalyst loading, dye concentration, pH, temperature, etc. was also studied in order to get maximum output. Highlights High reactivity toward water can be reduced by tailoring the niobium alkoxides with chloroacetic acid and dichloroacetic acid. The tailored niobium alkoxides exhibit slower rate of hydrolysis with respect to the parent alkoxides. The gelation is extended in the heteroleptic-modified alkoxides. The nanoparticles derived from modified niobium alkoxides possess suitable band gaps for photocatalysis. The various conditions of photocatalytic removal of rhodamine B were also optimized.