Exploring the role of tamarind seed husk derivatives for the enhanced photocatalytic degradation efficiency of meso -TiO2: via improved superoxide anion radicals generation and visible light absorption

Abstract

A novel nanocomposite of tamarind seed husk (TSH) supported mesoporous titanium dioxide (m-TiO2) nanoparticle (TTSH) was prepared by employing a simple wet-impregnation technique. The chemical composition of the prepared TSH was predicted as gallic acid and proanthocyanidin (PA) derivatives such as epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) using FT-IR and 13C NMR characterization. The XRD and HR-TEM studies clearly revealed the structural and morphological properties of TTSH. The adsorption studies were performed and compared for m-TiO2, TSH and TTSH under dark conditions. In comparison to bare m-TiO2, TSH with the functional groups COC, -CO and -OH showed greater adsorption capacity towards the cationic dye methylene blue (MB). TSH (2.588 mgL−1sec−1) showed a higher rate than m-TiO2 (2.145 mgL−1sec−1) for the degradation of MB under direct solar light. The TTSH nanocomposite contributed enough superoxide anion radicals (O2.−), which yields .OH radicals on further series of redox reactions for the degradation of MB. TSH extended the light absorption edge position of m-TiO2 to the visible region from 400 to 480 nm, hence TTSH functioned as a visible responsive material. This research work brings TSH into the spotlight on a cost-efficient and eco-friendly support material to improve the degradation efficiency of photocatalysts.