Zheng Chunzhi

Preparation of High Activity TiO 2 /g-C 3 N 4 Photocatalysts via a Facile Sol-gel Method with Ti(OBu) 4 as Ti Source and Melamine as Nitrogen Source

Abstract A highly active photocatalyst TiO 2 /g-C 3 N 4 was synthesized by a facile two-step method including sol-gel and calcination, using Ti(OBu) 4 as a Ti source and melamine as a nitrogen source. The resultant photocatalysts were characterized by XRD, TEM and UV-vis diffuse reflectance spectra. The results show that TiO 2 /g-C 3 N 4 is formed and TiO 2 is beset with graphite-like carbon nitride of layer structure. TiO 2 /g-C 3 N 4 exhibits obviously enhanced visible light photocatalytic activity, and the degradation efficiency of Methylene blue (MB) reaches 94.46% after irradiation for 1 h, which is much higher than that of g-C 3 N 4 and TiO 2 . The improved photocatalytic activity of TiO 2 /g-C 3 N 4 is attributable to its wide spectrum responsive range, strong visible light adsorption capability, and the synergistic effect between TiO 2 and g-C 3 N 4 . The mechanism of photocatalytic reaction was discussed.

High-concentration Facile Synthesis of Self-assembled Micronsized Flower Silver Particles by Stainless Steel-Assisted Vitamin C Reduction Method

Self-assembled micronsized flower silver (Ag) particles were synthesized using AgNO3 as starting material by a stainless steel assisted vitamin C (Vc) reduction method. X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to characterize the phases and the morphologies of the products. The results show that the micronsized flower Ag particles with 1∼6 µm size can be rapidly and routinely produced on relatively large scales, which are composed of nanoplates or nanorods with the thickness of around 200 nm. The growth process of the micronsized flower Ag particles was investigated and their growth mechanism was proposed. It is revealed that the micronsized flower Ag particles might be assembled from small particles step by step. The presence of stainless steel and temperature plays an important role in determining the geometric shape and the size of micronsized flower Ag particles.