During the photocatalytic reduction process, photocatalyst nanoparticles are assembled onto graphene sheets to form photocatalyst-graphene composites. Herein, we report the synthesis of SrTiO3-graphene nanocomposites via the photocatalytic reduction method. The photocatalytic activity of the composites was evaluated by the degradation of acid orange 7 (AO7) under ultraviolet (UV) light irradiation, and the photocatalytic find more mechanism

involved was discussed. Methods SrTiO3 nanoparticles were synthesized via a polyacrylamide gel route as described in the literature [25]. The graphene oxide used in this research was purchased from Nan-Jing XF Nano Materials Tech Co. Ltd. (Nanjing, China). SrTiO3-graphene composites were prepared via a photocatalytic reduction route. A certain amount of graphene oxide was dispersed in 50 mL distilled water, followed by ultrasonic treatment of the suspension for 30 min. Then, 0.1 g SrTiO3 nanoparticles and 0.0125 g ammonium oxalate (AO) were added to the suspension PF-6463922 clinical trial under magnetic stirring. After GS-9973 stirring for 10 min, the mixture was purged with nitrogen and exposed to UV light irradiation from

a 15-W low-pressure mercury lamp for 5 h under mild stirring. During the irradiation, the color of the mixture changed from brown to black, indicating the reduction of the graphene oxide. After that, the product was separated from the reaction solution by centrifugation at 4,000 rpm for 10 min, washed several times with distilled water and absolute ethanol, and then dried in a thermostat drying oven at 60°C

for 4 h to obtain SrTiO3-graphene composites. A Nintedanib (BIBF 1120) series of samples were prepared by varying the weight fraction of graphene oxide from 2.5% to 10%. The photocatalytic activity of the samples was evaluated by the degradation of AO7 under UV light irradiation of a 15-W low-pressure mercury lamp (λ = 254 nm). The initial AO7 concentration was 5 mg L-1 with a photocatalyst loading of 0.5 g L-1. Prior to irradiation, the mixed solution was ultrasonically treated in the dark to make the photocatalyst uniformly dispersed. The concentration of AO7 after the photocatalytic degradation was determined by measuring the absorbance of the solution at a fixed wavelength of 484 nm. Before the absorbance measurements, the reaction solution was centrifuged for 10 min at 4,000 rpm to remove the photocatalyst. The degradation percentage is defined as (C 0 - C t) / C 0 × 100%, where C 0 and C t are the AO7 concentrations before and after irradiation, respectively. To investigate the photocatalytic stability of the SrTiO3-graphene composites, the recycling tests for the degradation of AO7 using the composite were carried out. After the first cycle, the photocatalyst was collected by centrifugation, washed with water, and dried.