A novel floating visible-light photocatalyst (HGMs–TiO2/Ag3PO4) composite was prepared using amino modified low-density hollow glass microspheres (HGMs) as carriers to disperse and support TiO2 and Ag3PO4 photocatalysts. The surface morphology, crystal structure and optical properties of the HGMs–TiO2/Ag3PO4 composites were characterized and the Ag3PO4 content on the surface of the microspheres was determined by atomic absorption spectrometry (AAS). Methylene blue (MB) was chose as the organic pollutant to investigate the visible-light catalytic properties of the HGMs–TiO2/Ag3PO4 composites. For HGM composite photocatalysts, when the theoretical mass ratio of TiO2 to Ag3PO4 on the surface of HGMs is 1 : 1.5, the visible-light catalytic activity of the composite is superior to pure Ag3PO4 and a TiO2/Ag3PO4 photocatalyst with a mass ratio of 1 : 1.5 under the same conditions, due to the increased light-contact area and the photocatalytic active sites, since the TiO2 and Ag3PO4 particles can be well dispersed on the surface of the floating HGMs. Furthermore, the deposits of TiO2 and Ag3PO4 on the HGM surface form a heterostructure, facilitating the separation of electron–hole (e− – h+) in the energy band, and elevating the photocatalytic activity and cycle stability of Ag3PO4. This work indicates that floating HGMs–TiO2/Ag3PO4 composites could become a promising photocatalyst for organic dye removal due to the low cost and high visible-light responsiveness.
Ag 3 PO 4 exhibits a high photocatalytic activity if exposed to visible light, however, it displays bottlenecks such as poor cycle-stability and mediocre ability to degrade methyl orange (MO) because of limited adsorption of MO molecules onto its surface. In this study, nano TiO 2 prepared by a one-step method was combined with Ag 3 PO 4 to form a TiO 2 @Ag 3 PO 4 heterojunction in order to improve this material both in terms of photocatalysis and photostability. After adding a KH-570 silane coupling agent, the photocatalytic performance of TiO 2 @Ag 3 PO 4 could be improved even further, with the degradation rate of MO maintained at more than 90% after three cycles of visible in light.
Junjie Ma,Yingguan Xiao,Juanrong Chen,Yue Shen,Sisi Xiao,Shunsheng Cao
Exploring high-performance photocatalysts still remains a big challenge due to poor charge separation efficiency. Herein, we prepare a novel anatase/rutile TiO 2 -Ag 3 PO 4 hollow photocatalyst (A/R-TiO 2 -Ag 3 PO 4 ) for addressing this challenge. Microstructural characterization and photoelectric measurements confirm that the synergy of hollow structure and dual-heterojunction can provide abundant active sites and boost efficient charge separation through dual-pathway charge transfer mechanism. The A/R-TiO 2 -Ag 3 PO 4 photocatalyst exhibits the highest photocurrent density (15.25 µA cm −2 ), which is 8.4 and 5.2 times than that of A-TiO 2 -Ag 3 PO 4 (1.82 µA cm −2 ) and P25-Ag 3 PO 4 (2.93 µA cm −2 ), respectively. Photo-degradation experiment shows that A/R-TiO 2 -Ag 3 PO 4 presents a high degradation percentage (98.7 %) of thiamethoxam (THX) within 30 min, which is 1.45 and 1.23 times than that of A-TiO 2 -Ag 3 PO 4 (68.1 %) and P25-Ag 3 PO 4 (80.7 %), respectively. Furthermore, the degradation percentage of THX by A/R-TiO 2 -Ag 3 PO 4 is as high as 96.4 % after seven successive cycles, indicating excellent cycling stability. Therefore, this work provides a new insight into exploring other high-performance photocatalysts by combining hollow structure and dual-heterojunction.
In the photocatalytic process, mixed-phase TiO 2 tends to have more carrier transport channels compared with single-phase TiO 2 , which can further accelerate the separation of photogenerated carriers. In this study, biphasic TiO 2 nanofibers containing both rutile and anatase phases were synthesized by electrostatic spinning technique. Subsequently, a variety of biphasic TiO 2 /Ag 3 PO 4 nanofiber photocatalytic materials with different ratios were prepared by combining the in situ growth process. The test results confirm that not only heterojunctions are formed between the components of the composites, but also the optical properties are improved. When the content of Ag 3 PO 4 was 25 wt%, the composite showed excellent photocatalytic activity for both rhodamine B (RHB) and methyl orange (MO). In addition, the main active substances and stability of the composite were investigated by doing active agent capture experiments and stability tests, and a reasonable photocatalytic mechanism was proposed on the basis of the relevant test results.
危险品化学品经营许可证（带存储）