Supporting Information Improved visible light photocatalytic activity of rGO-Fe 3 O 4 -NiO hybrid nanocomposites synthesized by in-situ facile method for industrial wastewater treatment applications Shanmugam Mahalingam and Young-Ho Ahn * Department of Civil Engineering, Yeungnam University, Gyeongsan, 38541, Republic of Korea * Correspondence author: Department of Civil Engineering, Disasters Prevention Research Institute, Yeungnam University, Gyeongsan, 38541, Republic of Korea; Tel: +82-53-810- 3511; Fax: +82-53-810-4622; E-mail: yhahn@ynu.ac.kr (Young-Ho Ahn) S 1 Schematic diagram of the synthesis of the rGO-Fe 3 O 4 -NiO hybrid nanocomposites Electronic Supplementary Material (ESI) for New Journal of Chemistry. This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018