Shape-, size- and phase-controlled indium oxide for gas sensing

In the last years operando and in situ spectroscopic tools have been developed and adapted to follow the physicochemical processes taking place in an active sensing element in real time and under operating conditions. Besides the monitoring of the processes responsible for gas sensing in the ldquolivingrdquo sensors, the control over crystalline structure and morphology of a sensing material has a particular significance. In our presentation we will summarize the recent achievements in the understanding of the In-O structural chemistry; a special attention will be paid at the phase transitions as well as the stability of individual In
₂
O
₃
phases under conditions close to operating conditions of sensors (including also in situ investigations). For the first time we will report on the experimental verification of the metastability of corundum-type indium oxide under operating conditions and its seemingly cube-shaped morphology.