Photoactivity of CdS particles grown in Pt-loaded zeolite Y

An integrated photocatalyst was prepared and its photoelectrocatalytic behavior for solar energy conversion was investigated. To make an integrated photocatalyst for hydrogen evolution, Pt and CdS clusters were embedded in zeolite as a cocatalyst and a photocatalyst, respectively. Pt particles were embedded in zeolite Y by ion exchange reaction with Pt (NH₃)₄²⁺ and activation and reduction processes were followed. CdS clusters in zeolite Y cages were prepared by ion exchange reaction with Cd²⁺ and sulfurization with Na₂S in aqueous solution was followed. The existence of CdS clusters in the cavities of zeolite Y was detected by IR spectra. UV absorption edges of the samples prepared show blue shifts about 0.03-0.12 eV from the edge of bulk CdS, which is an indication of CdS clusters formed in zeolite Y. The pore structure of samples was analyzed by BET and Langmuir method. The solar energy conversion into hydrogen was investigated, where sodium tartrate solution was used as a hole scavenger. We could observe that 1 wt% Pt supported sample was the most effective photocatalyst for hydrogen evolution (62 μL/mg after 4 hour reaction).