A hybrid of CdS/HCa2Nb3O10 ultrathin nanosheets for promoting photocatalytic hydrogen evolution

Abstract

A hybrid of CdS/HCa₂Nb₃O₁₀ ultrathin nanosheets was synthesized successfully through a multistep approach. The structures, constitutions, morphologies and specific surface areas of the obtained CdS/HCa₂Nb₃O₁₀ were characterized well by XRD, XPS, TEM/HRTEM and BET, respectively. The TEM and BET results demonstrated that the unique structural features of CdS/HCa₂Nb₃O₁₀ restrained the aggregation of CdS nanoparticles as well as the restacking of nanosheets effectively. HRTEM showed that CdS nanocrystals of about 25–30 nm were firmly anchored on HCa₂Nb₃O₁₀ nanosheets and a tough heterointerface between CdS and the nanosheets was formed. Efficient interfacial charge transfer from CdS to HCa₂Nb₃O₁₀ nanosheets was also confirmed by EPR and photocurrent responses. The photocatalytic activity tests (λ > 400 nm) showed that the optimal hydrogen evolution activity of CdS/HCa₂Nb₃O₁₀ was about 4 times that of the bare CdS, because of the efficient separation of photo-generated carriers.