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

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.