Au nanoparticles embedded on urchin-like TiO2 nanosphere: An efficient catalyst for dyes degradation and 4-nitrophenol reduction

The development of efficient heterogeneous catalysts for degrading organic pollutants or converting them into harmless and even useful products is of vital significance for environmental remediation. Herein, we reported the facile synthesis of a highly active and stable nanocatalyst (AuNPs/uTiO(2)) via a simple photoreduction deposition of Au nanoparticles (AuNPs) on urchin-like TiO2 nanosphere (uTiO(2)), and demonstrated its excellent performances as a catalyst for oxidative degradation of organic dyes and reductive conversion of 4-nitrophenol (4-NP). The AuNPs/uTiO(2) nanocomposite showed high surface area (147.5 m(2)center dot g(-1)), large pore volume (0.52 cm(3)center dot g(-1)), and high dispersity of AuNPs. In particular, the uTiO(2) support could combine AuNPs strongly and serve as a shield to prevent leaching or aggregation of AuNPs, while allowing guest organic molecules to diffuse in and out easily. Benefiting from the excellent characteristics, the AuNPs/uTiO(2) exhibited superior catalytic properties for dyes degradation and 4-NP reduction with significantly higher catalytic efficiencies than many,previously reported heterogeneous catalysts. Moreover, the catalytic activity of AuNPs/uTiO(2) could remain almost unchanged after being recycled for several times, demonstrating its long-term stability. The AuNPs/uTiO(2), combining the advantages of high activity, favorable kinetics, and excellent durability for dye degradation and 4-NP reduction, should be very promising for wastewater treatment. (C) 2017 Elsevier Ltd. All rights reserved.