Building nestlike microsphere Nb2O5:Tb3+ for effective catalytic degradation

Nb2O5:Tb3+ nestlike microspheres have been synthesized by a self-assembly of nanosheets using the composite-hydroxide-mediated method. The characterizations of X-ray diffraction, scanning electron microscopy, transmission electron microscopy and high resolution transmission electron microscopy show the Nb2O5:Tb3+ crystals have a monoclinic phase, polycrystalline structure, unique nestlike shape, and an average diameter of ∼1 μm. Comparing UV–vis spectrum of Nb2O5:Tb3+ microspheres with that of Nb2O5 nanoparticles, we have found the red shift of absorption edge of Nb2O5:Tb3+ microspheres due to the impurity band formation. The catalytic activity of Nb2O5:Tb3+ microspheres has also been compared with that of the Nb2O5 nanoparticles, indicating an excellent catalytic degradation activity of the Nb2O5:Tb3+ microspheres to methyl orange owing to its hierarchical structure and effective absorption of light. The effective catalytic degradation activity suggests its possible application in the organic pollutant treatment.