AIP Conference Proceedings [Author(s) PROCEEDING OF THE 3RD INTERNATIONAL CONFERENCE OF GLOBAL NETWORK FOR INNOVATIVE TECHNOLOGY 2016 (3RD IGNITE-2016): Advanced Materials for Innovative Technologies - Penang, Malaysia (27–29 January 2016)] - Effect of sodium tungstate dehydrate concentration on the growth of tungsten oxide layer grown on polyethylene terephthalate fiber and its photocatalytic in removal of RhB dye under visible light irradiation