Atomically dispersed Pt on MOF-derived In2O3 for chemiresistive formaldehyde gas sensing

Single-atom catalysts (SACs) supported on inorganic materials have been confirmed as effective active sites in catalytic reaction. In order to develop gas sensing material with high performance, we reported an atomically dispersed Pt on MOF-derived In2O3 via N doped graphene (NG) sacrificial templating route for the first time. This synthesis strategy, which combines metal-organic frameworks (MOF) precursor and NG template, not only greatly regulates the physicochemical properties of In2O3, but also makes the single-atom Pt be anchored on In2O3. Herein, the effect of Pt and NG was discussed based on various characterization methods. Gas sensing tests revealed that the highly dispersed Pt helps to improve the HCHO sensing performance. The Pt SACs inclusion increases the specific surface area, the contents of oxygen vacancies and adsorbed oxygen species of In2O3, thus increasing the active sites on the surface. These enhancements result in high response (750.4 to 100 ppm), good selectivity, rapid response (2 s to 100 ppm) and low theoretical limit of detection (8.4 ppb) of Pt1-In2O3 based sensor to HCHO. In a word, atomically dispersed Pt loaded MOF-derived In2O3 is an efficient sensing material for selective detection of HCHO.