In this work, a new method for the growth of large CdS crystals into PdS/ZnS--CdS-type photocatalysts is presented. In order to accomplish this, in the first stage zinc sulphide was synthesised and hydrothermally crystallised. In the second stage, after PdS decoration, the recrystallised zinc sulphide was utilised as sulphur source for the synthesis of PdS/ZnS--CdS-type photocatalysts. The photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. In the third stage magnetic polymer supports were manufactured and loaded with photocatalyst. Finally photocatalysis experiments under blue light illumination were conducted for the hydrogen evolution reaction in the presence of sulphite and sulphide ions on both suspension and polymer supported photocatalysts. The photocatalysts' efficiency increased by about 70% along with the PdS quantity increase from 0.11% to 0.89%. The use of magnetic polymer may be a solution for reducing the costs necessary to maintain the photocatalysts in suspension.