Indoor Air Photocatalytic Decontamination by UV–Vis Activated CuS/SnO2/WO3 Heterostructure

Abstract

A titania-free heterostructure based on CuS/SnO2/WO3 was obtained by a three-step sol–gel method followed by spray deposition on the glass substrate. The samples exhibit crystalline structures and homogenous composition. The WO3 single-component sample morphology consists of fibers that serve as the substrate for SnO2 development. The CuS/SnO2/WO3 heterostructure is characterized by a dense granular morphology. Photocatalytic activity was evaluated under UV–Vis radiation and indicates that the WO3 single-component sample is able to remove 41.1% of acetaldehyde (64.9 ppm) and 52.5% of formaldehyde (81.4 ppm). However, the CuS/SnO2/WO3 exhibits a superior photocatalytic activity due to a larger light spectrum absorption and lower charge carrier recombination rate, allowing the removal of 69.2% of acetaldehyde and 78.5% of formaldehyde. The reusability tests indicate that the samples have a stable photocatalytic activity after three cycle (12 h/cycle) assessments. During light irradiation, the heterostructure acted as a Z-scheme mechanism using the redox ability of the CuS conduction band electrons and the SnO2/WO3 valence band holes to generate the oxidative species required for VOC removal.

Achieving One Part Per Billion Hydrogen Sulfide (H2S) Level Detection through Optimizing Composition and Crystallinity of Gold-Decorated Tungsten Trioxide (Au-WO3) Nanofibers

“…An interesting correlation emerges where increases in the Au concentration, calcination duration, and calcination temperature reduce the band gap energy. These measured band gap energies correspond closely with values reported in previous studies, demonstrating a consistent pattern with our work. – The reduction of band gap can be elucidated by the presence of intermediate states within the conduction and valence bands of the WO 3 host structure. The reduction in band gap energy can be explicated through the introduction of intermediary energy states within the conduction and valence bands of the host matrix with additional Au.…”

Synthesis of BiOX-Red Mud/Granulated Blast Furnace Slag Geopolymer Microspheres for Photocatalytic Degradation of Formaldehyde

“…Therefore, the methods of formaldehyde detection and removal have attracted extensive attention from governments and scholars. Currently, the main ways to deal with formaldehyde are physical adsorption, photocatalytic degradation and biodegradation [3,4]. The traditional adsorption technology has a low adsorption capacity, and this shortcoming is especially obvious when the concentration of formaldehyde is low [5].…”