Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1275912 | International Journal of Hydrogen Energy | 2013 | 8 Pages |
ZnIn2S4/CdIn2S4 composite photocatalysts (x = 0–1) were successfully synthesized via a hydrothermal route. Compositions of ZnIn2S4/CdIn2S4 composite photocatalysts were optimized according to the photocatalytic H2 evolution rate. XRD patterns indicate the as-prepared samples are mixtures of hexagonal and cubic structures. FESEM and TEM images show that the as-prepared samples are composed of flower-like microspheres with wide distribution of diameter. There is obviously distinguishing distribution of Zn, Cd elements among the composite architectures. UV–vis absorption spectra of different compositions exhibit that absorption edges of ZnIn2S4/CdIn2S4 composites slightly move towards longer wavelengths with the increment of CdIn2S4 component. A typical time course of photocatalytic H2 evolution from an aqueous Na2SO3 and Na2S solution over unloaded and PdS-loaded ZnIn2S4/CdIn2S4 composite photocatalyst is carried out. The initial activity for H2 evolution over 0.75 wt% PdS-loaded sample is up to 780 μmol h−1. And the activity of unloaded sample also reaches 490 μmol h−1 with consistent stability.
Graphical abstractZnIn2S4/CdIn2S4 composite photocatalysts were successfully synthesized via a hydrothermal route for the first time. Due to the synergetic effect of ZnIn2S4 and CdIn2S4 components, composite photocatalyst exhibited an enhanced performance compared with single ZnIn2S4 or CdIn2S4 photocatalyst. Pt and PdS cocatalysts were used as probes to evaluate the rate-determining step of the total hydrogen evolution reaction. Furthermore, unloaded ZnIn2S4/CdIn2S4 composite photocatalyst showed an unexpected cycling performance that the rate of H2 evolution even increases after each run.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► ZnIn2S4/CdIn2S4 composites were synthesized via a facile hydrothermal route. ► The activity for H2 evolution over PdS-loaded sample is up to 780 μmol h−1. ► A mechanism was proposed to explain the outstanding performance for H2 evolution.