Natural Sunlight Driven Photocatalytic Removal of Toxic Textile Dyes in Water Using B-Doped ZnO/TiO2 Nanocomposites

Abstract

A novel B-doped ZnO/TiO2 (B–ZnO/TiO2) nanocomposite photocatalyst was prepared using a mechanochemical–calcination method. For the characterization of the synthesized B–ZnO/TiO2 photocatalyst, XRD, FESEM-EDS, FTIR, UV-Vis DRS, BET, PL, and XPS techniques were used. The bandgap energy of B–ZnO/TiO2 was reduced, resulting in enhanced visible-light absorption. Significant PL quenching confirmed the reduction in the electron–hole recombination rate. Furthermore, reduced crystallite size and a larger surface area were obtained. Hence, the B–ZnO/TiO2 photocatalyst exhibited better photocatalytic activity than commercial TiO2, ZnO, B–ZnO, and ZnO/TiO2 in the removal of methylene blue (MB) dye under natural sunlight irradiation. The effects of various parameters, such as initial concentration, photocatalyst amount, solution pH, and irradiation time, were studied. Under optimal conditions (MB concentration of 15 mg/L, pH 11, B–ZnO/TiO2 amount of 30 mg, and 15 min of operation), a maximum MB removal efficiency of ~95% was obtained. A plausible photocatalytic degradation mechanism of MB with B–ZnO/TiO2 was estimated from the scavenger test, and it was observed that the •O2− and •OH radicals were potential active species for the MB degradation. Cyclic experiments indicated the high stability and reusability of B–ZnO/TiO2, which confirmed that it can be an economical and environmentally friendly photocatalyst.

Synthesis of CeO2/ZrO2/ZnO nano alloy oxide and investigation of photocatalysis of naphthol orange under sunlight

“…For this purpose, ascorbic acid, ethylenediaminetetraacetic acid (EDTA), and isopropyl alcohol (IPA) were used to trap superoxide radical anion (O 2 ˙ − ), holes (h + ), and hydroxyl radical (˙OH), respectively. 37,40 In each of these cases, the reaction conditions remained the same, and 10 mM sacrificial agents were added to the NO dye solution before the addition of the photocatalyst. The degradation rate was measured after 50 min.…”

The synergistic degradation of pollutants in water by photocatalysis and PMS activation

“…Instead, it causes the hybrid valence band electrons to shift upwards, reducing the band gap width and enhancing the photocatalytic performance of the semiconductor. Nonmetal elements commonly include N (Ren et al, 2008; Sheng et al, 2008), C (Mohamed et al, 2019; Yang et al, 2021; Zhao et al, 2019; Zou et al, 2020), S (Mahyari et al, 2016; Wang et al, 2008), F (Shi, Qin, Yang, & Zhang, 2012; Liu et al, 2016), and B (Shathy et al, 2022; Wang, Wang, Wang, et al, 2022). For example, Osin et al (2018) synthesized a mesoporous carbon and nitrogen co‐doped TiO 2 (C, N‐TiO 2 ) photocatalyst using sol–gel method combined with calcination.…”

Photocatalytic Removal of Metronidazole Antibiotics from Water Using Novel Ag-N-SnO2 Nanohybrid Material

“…To achieve the full mineralization of the pharmaceutical waste into CO 2 , H 2 O, and N 2 , an advanced oxidation process (AOP), particularly heterogeneous photocatalysis, is a potential technique for treating wastewater that contains MNZ [ 2 , 9 ]. AOP involves the use of visible and UV light to form a pair of electrons and holes (e − /h + ) at the photocatalyst surface, which results in the formation of hydroxyl radicals ( • OH) [ 10 ].…”