Influence of the solvent on the structure, morphology and performance for H2 evolution of CdS photocatalysts prepared by solvothermal method

CdS crystals with different morphologies, nanorods, sheets, microspheres and irregular particles have been obtained by changing the solvothermal solvent (ethylenediamine, diethylenetriamine, triethanolamine and ethanol). Characteristics of the solvothermal solvents, such as dielectric constant, ion-coordination and length of an atomic chain, have influence on the nucleation and growth of CdS crystals. The differences in the morphological and structural characteristics of the CdS crystals have strong influence on their photophysical properties as well as in their photoactivity for hydrogen production under visible light from aqueous solutions containing Na2SO3 and Na2S as sacrificial electron donor agents. The hydrogen production rate on CdS samples decreases in the order: nanorods (ethylenediamine) > sheets (diethylenetriamine) > irregular particles (triethanolamine) >> microspheres (ethanol). Variations in photoactivity were analysed taking into account the changes in the morphology, structure, surface and light absorption ability of CdS crystals.