Template-Free Preparation of Volvox-like Cd xZn1− xS Nanospheres with Cubic Phase for Efficient Photocatalytic Hydrogen Production.

Volvox-like Cd _xZn_{1− x}S solid solutions with a cubic zinc blend structure were synthesized through a template-free ethylene glycol process. Cd(Ac)₂ ⋅2 H₂O, Zn(Ac)₂ ⋅2 H₂O, and thiourea are used as the starting materials and dissolved in ethylene glycol. These reaction precursors and solvent not only contributed to control over the formation of the volvox-like spherical geometry, but also exerted vigorous domination for existence of cubic-phase Cd _xZn_{1− x}S nanostructures. As-prepared volvox-like Cd _xZn_{1− x}S nanospheres have a diameter of around 100 nm with extensional shells. These samples show excellent photocatalytic H₂ evolution activity from water splitting under visible-light irradiation without any cocatalyst or scaffolding, owing to their tunable band gap, cubic zinc blend structure, and unique hierarchical porous structure with a high surface area (as high as 95.2 m² g⁻¹). [ABSTRACT FROM AUTHOR]