Room temperature sequential ionic deposition (SID) of Ag2S nanoparticles on TiO2 hierarchical spheres for enhanced catalytic efficiency

Porous TiO2 hierarchical spheres with high surface area synthesized via a solvothermal method were successfully modified with an Ag2S co-catalyst by a sequential ionic deposition (SID) method at room temperature. The presence of Ag2S facilitated efficient charge separation, thus reducing recombination and enhancing the photocatalytic activity of the photocatalyst. The enhanced photocatalytic performance was demonstrated by water splitting where hydrogen (H-2) gas was produced at an evolution rate of 708 mmol h(-1) g(-1) and methyl orange was degraded with a rate constant of 0.018 min(-1). This is the first time that photocatalytic water splitting using a suspension system has been demonstrated on a Ag2S/TiO2 hierarchical heterostructure and the material shows stability in its photocatalytic performance despite being recycled several times. The composite material presents properties which are highly promising for the generation of clean energy and environmental clean up applications.