Through comparing the photocatalytic performance of microscale ZnO, nano ZnO, and Degussa P25 titania (P25), it was found that the microscale ZnO exhibited 2.6-35.7 times higher photocatalytic activity for the photodegradation of various dye pollutants than P25 under both UV-visible and visible irradiation and showed much better photostability than the nano ZnO. The photocatalysts were characterized with XRD, Raman, BET, DRUV-vis, adsorption of dye, photoelectrochemical measurement, and PL. The much higher photocataltyic activity of the microscale ZnO than P25 under UV-visible irradiation is attributed to the higher efficiency of generation, mobility, and separation of photoinduced electrons and holes. The much higher visible photocataltyic activity of the microscale ZnO than P25 is due to the higher photosensitization efficiency of electron transfer from an excited dye to the conduction band of the microscale ZnO than that of P25. The much better photostability of the microscale ZnO than the nano ZnO is due to its better crystallinity and lower defects. The photostability of the microscale ZnO is greatly improved by the surface modification of ZnO with a small amount of TiO(2). On the basis of the excellent photocatalytic performance of the microscale ZnO and TiO(2)-modified ZnO, a novel device of coupling photodegradation with light-to-electricity conversion was developed, which is a promising candidate for the photocatalytic removal of dye pollutants and a renewable energy source.

Nano-scale MOF composite materials prepared by combining inorganic semiconductors with controllable pore structures and functional active sites for the effective removal of organic dyes will exhibit more excellent adsorption activity.

No abstract

In this paper, we designed and synthesized a novel structure ZnO with the nanosheets grown on the surface of dumbbellshape ZnO via a simple hydrothermal route, and exhibits excellent photoelectrochemical performance. The reason is that nanosheets enhance charge generation, separation and transfer. Graphene as a co-catalyst and anti-photocorrosion material were coated on the surface of ZnO and further enhanced the photoelectrochemical properties. In process of photodegradation RhB, the experiments reveal that ZnO with 1.5 wt% RGO displayed highest rate constant of 0.0562 min À 1 , which is about 4 times better than pristine ZnO (heating 9 h) and several times higher than other RGO/ZnO composites. Meanwhile, the recycle experiments of 1.5 wt% RGO/ZnO suggest that it has excellent stability, reusability and excellent photocatalytic activity. The work provides a new strategy that developing nanosheets with high-energy plane grown on the surface of semiconductor particles to enhance photoelectrochemical performance and reusability. Results and discussionThe SEM images and TEM images were used to investigate the morphologies and structures of the ZnO-9, ZnO-10 and the . (a) Degradation efficiency of RhB catalyzed by ZnO and RZ-10 with different RGO contents; (b) pseudo-first-order kinetic plots; (c) the rate constant of samples; (d) Recycling photodegradation of RhB over 1.5 wt% RZ-10 under Xe lamp irradiation. 2 3 4 5 6 7 8