Novel La(OH)3 Integrated sGO-Ag3VO4/Ag Nanocomposite as a Heterogeneous Photocatalyst for Fast Degradation of Agricultural and Industrial Pollutants
La(OH)3 was integrated to sGO-Ag3VO4/Ag photocatalyst in a facile room temperature sonochemical deposition method. 2% (by weight) was found the optimal amount of La(OH)3 towards water pollutant degradation. A 20 min sunlight exposure of catalyst-methylene blue solution provided 99.95% degradation of the dye with 6.53 and 2.82 times higher activity than Ag3VO4 and sGO-Ag3VO4/Ag. A very high mineralization rate of two cationic (98%) and two anionic dyes (96%) were found in 1 h. The novel composite catalysed degradation of 4-chlorophenol (4-CP) and a dithiocarbamate fungicide, thiram with a total organic carbon (TOC) removal of 78% and 81% in 2-3 h. Degradation products were identified by mass spectroscopy as phenol and thiourea respectively. La(OH)3 increased and red shifted the absorption and decreased band gap to generate more charge carriers. Fine distribution of rice shaped La(OH)3 over the sGO-Ag3VO4/Ag surface remarkably enhanced the carrier transport leading to a decline in the e− - h+ recombination, proved by various techniques. Electrons from Ag3VO4 and Ag (0) travel through sGO sheet and reaches La(OH)3 to generate hydroxyl radicals in addition to holes and cause rapid rupture of bonds in pollutant by advanced oxidation process. Composite was found excellent towards real water detoxification with excellent stability, recyclability and photocatalytic activity.