Molecular-Linked Z-Scheme Heterojunction of Ti3+-Doped TiO2 and WO3 Nanoparticles for Photocatalytic Removal of Acetaldehyde

Abstract

Photocatalytic removal of indoor organic air pollutantsis effective,but there are practical limits to catalytic activation by indoor conditions.Here, we report a molecular-linked heterojunction of semiconductingmetal oxide nanoparticles (e.g., Blue TiO2 and WO3) that can be activated by wide-range light including an indoor light-emittingdiode (LED) under ambient conditions. Chemically reduced Blue TiO2 improves visible light absorption of white TiO2 by regulating the electronic structure with self-doping of Ti3+. The heterojunction between Blue TiO2 and WO3 is formed via a molecular linker, and a hybridized electronicstructure of a molecular-linked Z-scheme alignment is generated withoutchanges in chemical characteristics, increasing utilization of indoorlight and effectively improving electron-hole separation. WO3 sufficiently adapts to the photooxidative degradation ofair pollutants by (OH)-O-& BULL;, while Blue TiO2 leads to the effective generation of O-& BULL;(2) (-), leading to the complete decomposition of gaseousacetaldehyde (CH3CHO) to CO2 and CO withoutremaining organic byproducts (e.g., formaldehyde). As a robust interfacialcontact, molecular-linked heterojunctions provide efficient chargeseparation and highly stable performance and enhance solution-processablehomogeneous coatings of metal oxide photocatalysts on real surfaces. Copyright © 2023 American Chemical Society