Supporting Information Ultra Small Gold Nanoparticles-Graphitic Carbon Nitride Composite: An efficient catalyst for ultrafast reduction of 4-nitrophenol and removal of organic dyes from water Tanmay Bhowmik , Manas Kumar Kundu , Sudip Barman School of Chemical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Orissa - 751 005, India. Authors of equal contributions Electronic Supplementary Material (ESI) for RSC Advances. This journal is © The Royal Society of Chemistry 2015