The reduction of the band gap of titania is critically important to fully utilize its photocatalytic properties.Two main strategies, i.e. doping and partial reduction of Ti(IV), are the main alternatives available to date.Herein, we report a new synthesis strategy based on one-pot co-condensation of in situ prepared polymetallic titanium-alkoxide complexes with titanium tetrabutoxide. Using this direct reaction, it is possible to introduce organic compounds in the anatase phase, causing site distortions in the crystalline structure of the network. By using this strategy, a yellow and a black titania have been produced, with the latter showing a remarkable photocatalytic activity under visible-light.

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We report on the facile and low-temperature one-pot chemical synthesis of lightly doped Zn Cu O and hybrid Au-Zn Cu O photocatalysts with low Cu molar content (0< x < 0.7%) using 1,3-propanediol polyol simultaneously as solvent, reducing and a stabilizing agent, without any final thermal treatment. The photocatalysts have been characterized by X-ray diffraction, N adsorption study, UV-vis diffuse reflectance spectroscopy, inductively coupled plasma optical emission spectroscopy, and transmission electron microscopy. The lightly doped hybrid Au-Zn Cu O photocatalysts consisted in faceted quasi-spherical large-size Au nanoparticle cores surrounded by closely packed small-size Zn Cu O nanoparticles. Taking the photocatalytic degradation of Diuron under solar light as liquid-phase test reaction, the lightly doped Au-Zn Cu O hybrid photocatalysts with optimized x = 0.09% Cu content showed strongly enhanced photocatalytic activity when compared to the bare ZnO counterpart. The observed 16-fold higher degradation rate constant resulted jointly from the light doping of ZnO with Cu to form Zn Cu O photocatalyst and further from the addition of gold nanoparticles allowing interfacial oxide-to-metal electron transfer within the hybrid Au-Zn Cu O photocatalyst.