Synthesis of ZnSe microdisks and nanobelts and their visible-light photocatalytic properties

ZnSe photocatalytic films made of $$ \left\{ {000 1} \right\} $$ -ended microdisks and $$ \left\{ {2\overline{1} \overline{1} 0} \right\} $$ -ended nanobelts have been successfully synthesized via a solvothermal route followed by annealing in Ar atmosphere. Zn foils are used as both the Zn source and the substrate, Se powder as the Se source, and ethylenediamine (en) as the solvent. Lower temperature and Se concentration prefers the formation of $$ \left\{ {000 1} \right\} $$ -faceted ZnSe microdisks, while higher temperature and Se concentration leads to the formation of $$ \left\{ {2\overline{1} \overline{1} 0} \right\} $$ -faceted ZnSe nanobelts. Photoluminescence spectra show that both samples exhibit a visible-light emission, and ZnSe microdisks have more defects than ZnSe nanobelts. ZnSe microdisks have a superior photocatalytic activity over ZnSe nanobelts in the degradation of rhodamine B under visible light. The higher photocatalytic activity of ZnSe microdisks is attributed to larger amount of $$ \left\{ {000 1} \right\} $$ facets and defects in the ZnSe microdisks.