Photocatalytic properties of CdS and CdS—ZnS mixtures incorporated into the interlayer of layered compounds

Abstract

AbstractSemiconductor particles composed of CdS and mixed CdS—ZnS were incorporated into the interlayers of layered compounds such as H4Nb6O17, H2Ti4O9, montmorillonite and layered double hydroxides, [M(II)1‐xM(III)x(OH)2](CO3)x/2.nH2O(M(II) = Mg2+, Zn2+, M(III) = Al3+, x = 0.33), by the chemical reactions between S2‐ and Cd2+—Zn2+ and/or Cd(edta)2‐—Zn(edta)2‐ in the interlayers. The incorporated particles seemed to be very small, less than 1 nm thick. The band gap energies of CdS and CdS‐ZnS mixtures in the interlayer were significantly larger than those of normal‐crystalline ones. The CdS‐ZnS mixtures incorporated into the interlayers were capable of efficient hydrogen evolution following irradiation with visible light in the presence of Na2S, Na2SO3 and/or 2‐aminoethanol as a sacrificial donor. The hydrogen production activities of the CdS—ZnS mixtures incorporated into the interlayers were superior to those of unsupported CdS—ZnS. The incorporation of the CdS—ZnS mixtures in the interlayer of a semiconductor such as H2Ti4O9 and H4Nb6O17 was much more efficient in enhancing the hydrogen production activity than when an insulator such as montmorillonite and layered double hydroxide was used.