Dye removal by the designed carbon nanostructures@TiO2: infrared-assisted synthesis and methylene blue degradation

Abstract

Titanium dioxide (TiO₂) is applicable in photocatalysis and light-induced processes for activation of substrates, to be superiorly applicable for converting toxic containments into harmless fragments. Carbon nanostructures (CNs) are extensively attracted the attention of researchers, attributing to their diversity and exclusive physicochemical characters. Herein, the affinity of CNs either under acidic or basic conditions is studied for enhancing the catalytic potency of TiO₂ in order to be applicable without light, that is considered to be more economic, energy and cost-saving purposes. Currently, carboxymethyl starch was exploited as an origin for CNs under the infrared-assisted conditions. Afterward, CNs were successfully uploaded within TiO₂ under both acidic (CNs@TiO₂-formic) and basic (CNs@TiO₂-NaOH), to be applicable for catalytic degradation of methylene blue. CNs-formic were successfully prepared with slight smaller average size (6.6 ± 1.9 nm) rather than the base-CNs-NaOH (9.8 ± 3.7 nm). CNs@TiO₂-formic were exhibited with higher catalytic performance rather than CNs@TiO₂-NaOH. MB degradation percent reaches 98% after only 30 min by exploiting CNs@TiO₂-formic as a catalyst in the absence of light. Moreover, without irradiation, t_1/2 was superiorly shortened by nearly ten times under the catalytic performance of CNs@TiO₂-formic in the absence of light.