Spotting critical point from atomic sites to heterointerfaces on catalysts by oxygen adsorption energy-regulated luminescence

The atomic sites and heterointerfaces on metal oxides are crucial for the catalysts to exert their corresponding catalytic performances. Currently, high-resolution transmission electron microscopy (HRTEM) is generally employed to identify these two structures. However, it still remains challenging to determine the critical point from atomic sites to heterointerfaces, especially across a series of samples with doping levels ranging from trace to equivalent amounts. In this contribution, we have developed a facile strategy for spotting the critical point from atomic sites to heterointerfaces on Zr-doped In₂O₃ phase (In₂O₃/ZrO₂) via the diethyl ether-triggered luminescence. It is disclosed that the critical point between atomic and heterointerface gives a relatively weak luminescence, which is attributed to the lower oxygen adsorption energy; in comparison, both atomic and heterointerface structures could result in stronger luminescence due to their relatively higher activation ability of oxygen. Therefore, an "on-off-on" luminescence probe has been successfully built for probing the critical point on In₂O₃/ZrO₂ samples. Moreover, the universality of the proposed luminescence strategy has been further verified for other metal oxide catalysts, such as In₂O₃/CeO₂ and ZnO/ZrO₂. Our work has opened an alternative to HRTEM for determining the critical point from atomic sites to heterointerfaces on metal oxides through oxygen adsorption energy-regulated luminescence. It is anticipated that the proposed strategy could be beneficial in guiding the precise design of metal oxide catalysts with the atomic sites or heterointerfaces for their corresponding catalytic applications.