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Abstract

In this thesis, the effect and modification of nano-sized barium titanate and titanium dioxide in dye-sensitized solar cells (DSSCs) and water splitting are investigated. In the DSSCs work, barium titanate is used as a semiconductor photoanode, its effect on DSSCs and the influence of the material on open-circuit voltage and short-circuit current are investigated. For the water splitting research topic, firstly, barium titanate used in water splitting and the influence of its modifications through hydrogen reduction and co-catalyst loading on photocatalytic activities are investigated. Secondly, mesoporous titanium dioxide synthesized through a hard-templated method was applied in solar driven water splitting is investigated. The influences of synthetic methodology on the structure of the photocatalyst including its morphology, crystallinity and activity towards hydrogen production are evaluated. Especially, I highlighted the positive effect of surface area, composites and crystal phases on the photocatalytic activity in this topic.
Barium titanate based-semiconductors with or without compact TiO₂ layer modification were investigated in the dye-sensitized solar cells. The influence of barium titanate and coated layer on the solar cells' open-circuit voltage and short-circuit current were studied.
The photocatalytic activity of BaTiO₃ in water splitting is demonstrated and the effects of reduction treatment and platinum as a co-catalyst are studied. We found that the photocatalytic activity of reduced BaTiO₃ is enhanced by a factor of two compared to the original material. The most appropriate amount of Pt as co-catalyst is 1.0 wt.% in this thesis. The effect of Pt as co-catalyst on BaTiO₃ is non-linear.
Mesoporous TiO₂ with an ordered mesostructure, highly crystalline, thermally stable framework and high surface area has been synthesized by a nanocasting method with mesoporous carbon CMK-3 as a hard template. As a comparison to the commercial TiO₂ (P25), mesoporous TiO₂ was synthesized via hard-template that exhibiting large surface area, large pore volume and uniform mesopores. As a result, hard-templated mesoporous TiO₂ has the highest activity towards hydrogen production observed from all the samples reported in this thesis with solar light illumination.