Solar-light-active silver phosphate/titanium dioxide/silica heterostructures for photocatalytic removal of organic dye. (1st May 2020)

• Record Type: Journal Article
• Authors: Raza, Nadeem; Raza, Waseem; Gul, Hajera; Azam, Mudassar; Lee, Jechan; Vikrant, Kumar; Kim, Ki-Hyun
• Is Part Of: Journal of cleaner production. Volume 254(2020)
• Publication Date: 2020-05-01
• Subjects: Heterojunction -- Photocatalyst -- Silver phosphate -- Titanium dioxide -- Organic dye -- Silica felt; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2020.120031
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: A synergistic combination of surface adsorption capabilities and photocatalytic efficiency is crucial for the removal of pollutants from water. Here, the efficacy of such a process is explored through the assembly of a heterostructured photocatalyst (Ag3 PO4 /TiO2 /SiO2 ) by loading silver phosphate (Ag3 PO4 ) onto titanium dioxide (TiO2 : P25)-coated silica (SiO2 ) felt. This heterostructure demonstrated an enhanced tendency to absorb light due to its significantly low band-gap energy of 2.5 eV. As such, it exhibited enhanced photocatalytic performance to efficiently degrade an organic dye (methylene blue) under solar-light irradiation (e.g., 30% and 10% relative to pristine P25 and P25-coated SiO2 felt, respectively). The maximum degradation efficiency for methylene blue was 99% with a first-order kinetic model (k = 0.39 min −1 ). The calculated quantum yield of Ag3 PO4 /TiO2 /SiO2 (3.26 × 10 −3 molecules/photon) was significantly higher than that of other photocatalytic systems (e.g., ∼3260 times other reported hetrostructures, e.g., rGO/TiO2, Ni-doped/TiO2, and Cds/CoFe2 O4 ) with good reusability in terms of the degradation efficiency (e.g., 99% for the first cycle and 81% for the fourth). Ag3 PO4 /TiO2 /SiO2 is therefore recommended for the efficient treatment of organic pollutants in wastewater systems. Graphical abstract: Image 1 Highlights: A heterostructured photocatalyst (Ag3 PO4 /TiO2 /SiO2 ) was prepared for water purification. It showed enhanced performance relative to the P25 or TiO2 -coated silica felt. This new photocatalyst showed good reusability of 99% (1st cycle) to 81% (4th cycle)).