Photocatalytic carbon–carbon bond formation with concurrent hydrogen evolution on the Pt/TiO2 nanotube

The photocatalytic H2-production from water by using different aliphatic alcohols as sacrifice agent, over Pt/TiO2 nanotube, has been studied. The rate of H2-production over Pt/TiO2 showed the following trend: methanol > ethanol > i-propanol > n-propanol > sec-butanol > tert-butanol. Moreover, it was found that the aliphatic alcohols after photocatalytic reaction, including ethanol, n-propanol, i-propanol, sec-butanol and tert-butanol, were successfully coupled to corresponding dihydric alcohol such as 2,3-butanol, pinacol, 3,4-hexanediol, 3,4-dimethyl-3,4-hexanediol and 2,5-dimethyl-2,5-hexanediol. The effect of reaction condition on the CC coupling of alcohols was also investigated, and the possible mechanism of CC coupling depend on whether α-C radicals oxidized by hole or OH can fast strip from the TiO2 surface.