Mechanochemical synthesis of defective molybdenum trioxide, titanium dioxide, and zinc oxide at room temperature

Rui Li, Southwest University of Science and Technology
Jinhu Wang, Southwest University of Science and Technology
Yi He, Southwest University of Science and Technology
Faqin Dong, Southwest University of Science and Technology
Liang Bian, Southwest University of Science and Technology
Bowen Li, Southwest University of Science and Technology

© 2019 American Chemical Society. Publisher's version of record: https://doi.org/10.1021/acssuschemeng.9b00374

Abstract

Defect engineering on metal oxide semiconductors is considered as a versatile approach to regulate their properties. The traditional method for preparation of defective metal oxide semiconductors always requires harsh reaction conditions such as high temperature, high pressure, and explosive chemicals. Here we report an environmentally friendly mechanochemical synthesis way for preparation of several defective metal oxide semiconductors (MoO₃, TiO₂, and ZnO) in 10 g quantities by grinding semiconductor powders with ascorbic acid. The resulting vacancy-rich TiO₂ and ZnO show a strong visible-light absorption. Meanwhile, the obtained hydrogen-doped MoO₃ (H_0.5MoO₃) exhibits an exceptional localized surface plasmon resonance (LSPR), which follows Prout-Tompkins B1 solid-state reaction model. In addition, the plasmonic H_0.5MoO₃ is further utilized for colorimetric detection of H₂O₂. This colorimetric assay is able to determine concentrations of H₂O₂ from 0.05 to 3 mM with a detection limit of 30 μM. It can distinguish the presence of 3 mM H₂O₂ by the naked eye.