Titania anatase nanocrystals were prepared by sol‐gel/solvothermal synthesis in oleic acid at 250 °C, and modified by co‐reaction with Mo chloroalkoxide, aimed at investigating the effects on gas‐sensing properties induced by tailored nanocrystals surface modification with ultra‐thin layers of MoOx species. For the lowest Mo concentration, only anatase nanocrystals were obtained, surface modified by a disordered ultra‐thin layer of mainly octahedral MoVI oxide species. For larger Mo concentrations, early MoO2 phase segregation occurred. Upon heat treatment up to 500 °C, the sample with the lowest Mo concentration did not feature any Mo oxide phase segregation, and the surface Mo layer was converted to dense octahedral MoVI oxide. At larger Mo concentrations all segregated MoO2 was converted to MoO3. The two different materials typologies, depending on the Mo concentration, were used for …