Facile synthesis of hierarchically meso/nanoporous s- and c-codoped TiO₂ and its high photocatalytic efficiency in H₂ generation

Here, hierarchically meso/nanoporous TiO₂ was successfully fabricated by a facile and efficient hydrolysis and calcination method using Ti(OC₄H₉)₄ and K₂S₂O₈ as precursors. The hydrosol was firstly prepared by drop-wise adding ethanol dissolved Ti(OC₄H₉)₄ solution into acetone dissolved K₂S₂O₈ solution under a vigorous stirring and heating condition. After being sufficiently hydrolyzed, the hydrosol was calcined to promote the crystallization of TiO₂ and successfully dope S and C on TiO₂. The calcination temperature significantly affects the doping of S and C on TiO₂, crystallization of TiO₂, formation of hierarchically meso/nanoporous structure of TiO₂ and its light absorption capability. The S- and C-codoped TiO₂ exhibits high photocatalytic H₂ generation efficiency in a water/methanol sacrificial reagent system under the irradiation of UV light. The high photocatalytic efficiency is dependent on the comprehensively competing effects of the codoping of S and C, crystallization, specific surface area and light absorption capability. The S- and C-codoped TiO₂ calcined at 600°C demonstrates the highest photocatalytic H₂ generation efficiency, which is ascribed to the balanced synergy of the abovementioned factors.