Tuning the morphology of ZnO nanoparticles by Zn-clusters and application on the photoreduction of Cr(VI)

•Zn-MOFs are prepared and used to derive the ZnO nanoparticles.•The morphology of derived ZnO nanoparticles are related to the form of clusters.•The photocurrent of the ZnO nanoparticles is prominent comparing with Zn-MOFs.

The ZnO nanoparticles in a uniformed size have been applied as the photocatalysts over the reduction of Cr(VI). The morphologies of the ZnO nanoparticles are decided by the cluster type of mother sample Zn-MOFs, which are prepared with the same bi-ligands 1,3,5-benzenetricarboxylic acid (H3BTC) and phenanthroline (phen) in the presence of Zn ions. The SEM, TEM, infrared spectroscopy, thermogravimetric analysis and UV–vis study reveal the physical properties and structural information of ZnO nanoparticles. The reduction rate of Cr(VI) under the UV light irradiation indicates that the ZnO nanoparticles have higher activities with promoting reduction rate comparing with the related Zn-MOFs. The test of photocurrent approves the reduction ability of each sample.

Graphical abstractThe ZnO nanoparticles less than 200 nm are derived by calcinations of Zn-MOFs and display abundant mesopores with irregular shape. The enhanced photocurrent response of derived ZnO nanoparticles can be collected comparing with Zn-MOFs and control sample of ZnO. The reduction rate of Cr(VI) over the derived ZnO nanoparticles is higher than those Zn-MOFs and control sample.Figure optionsDownload full-size imageDownload as PowerPoint slide