The present work focuses on the improved synthesis of bimetallic catalyst, NiO impregnated CeO2, based on the use of ultrasound assisted approach with comparison with the conventional approach. Morphological characteristics of the catalyst have been established using TEM and BET analysis. In addition XRD and FTIR analysis was also performed to establish the crystallite size and the active functional groups that decide the catalytic activity respectively. It has been established that the catalyst synthesized in the presence of ultrasound showed better catalytic properties than the catalyst obtained using the conventional approach with the specific surface area increasing from 31.41 m(2)/g to 94.63 m(2)/g due to cavitational effects. TEM analysis also established the appearance of sharp edged and non-agglomerated nanopartides in the ultrasound assisted synthesis whereas in the case of conventional approach, agglomerates and higher particle/crystallite size was observed. The catalyst was subsequently used for the catalytic degradation of Brilliant Green dye using UV irradiation and ultrasonic irradiation. The catalytic activity of the catalyst obtained using ultrasound assisted approach was observed to be better than the catalyst obtained using conventional approach. UV induced extent of degradation using the catalyst synthesized in the presence of ultrasound was found to be 82% whereas using conventionally synthesized catalyst, much lower extent of degradation as 40% was obtained. TOC analysis was also performed which confirmed correspondence with the extent of degradation and better results for the ultrasonically obtained catalyst. Overall the ultrasound assisted approach has been demonstrated to be an effective approach for obtaining better quality NiO impregnated CeO2 catalyst with proven efficacy for decolourization using photocatalysis (higher activity) as well as sonocatalysis. (C) 2017 Elsevier B.V. All rights reserved.