Xiao-Hong Yang

Controlled synthesis of silver phosphate crystals with high photocatalytic activity and bacteriostatic activity

Symmetrical silver phosphate (Ag3PO4) crystals with porous structure were grown by a facile controllable route in aqueous solution. The Ag3PO4 crystals have a cubic-type structure and the morphologies are distinctive under different conditions. The crystals had high purity, were well-crystallized and were free of secondary phases by powder X-ray diffraction, IR, Raman spectra, scan electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). It is interesting that the different crystal faces of the crystals have high physical–chemical–biological activity and large surface areas, so as to act as high activity micro-reactors (HAMs). The HAMs can effectively improve the photocatalytic activity and bacteriostatic activity of the Ag3PO4 crystals. Furthermore, we proposed a possible growth mechanism and detailed morphology transformation process of Ag3PO4 crystals with different properties.

Construction of silver tungstate multilevel sphere clusters by controlling the energy distribution on the crystal surface

Silver tungstate (Ag2WO4) multilevel sphere clusters were synthesized for the first time by a dynamic-template route through controlling the energy distribution on the crystal surface. The polymerization reaction of acrylamide monomers as the dynamic-template on the surface of the Ag2WO4 crystals occurred, with more polymerization causing more high energy spots to appear on the surface of the Ag2WO4 crystals, and the change of energy caused by this affected the formation and growth of the multilevel sphere clusters. The Ag2WO4 multilevel sphere clusters were 2.5–2.8 μm in diameter and constituted several second level spheres which were about 0.8 μm in diameter. The XRD patterns indicated that the Ag2WO4 products were perfectly matched with the hexagonal-phase Ag2WO4 crystal system and the symmetric space type belonged to the P63 symmetric system. In addition, the Ag2WO4 products had good visible light photocatalytic performance and antimicrobial ability.

Thermal perturbation nucleation and growth of silver molybdate nanoclusters by a dynamic template route

Silver molybdate (Ag2MoO4) nanoclusters were first prepared by a dynamic template route under 20 °C. The heat released from the polymerization of the acrylamide (AM) assisted templates induced high active sites to be generated on the surface of the crystal where more attracted nuclei were adsorbed on. The continuously formed nuclei assembled together and the nanoclusters were formed. The paper provided an explanation for the formation of the Ag2MoO4 nanoclusters through the research on reaction conditions; on the other hand, the comparison of photocatalytic performance and antibacterial properties between the Ag2MoO4 nanoclusters and the Ag2MoO4 crystals of other morphologies showed that the Ag2MoO4 nanoclusters had better photocatalytic and antibacterial activities, which was a preliminary perspective for the application of the nanocluster materials.