Visible light-induced selective oxidation of alcohols with air by dye-sensitized TiO2 photocatalysis

Visible light-induced selective oxidation of alcohols to aldehydes or ketones with atmosphere oxygen was triumphantly achieved devoid of any redox mediator. A paradigm of dye-sensitized TiO2 photocatalysis was capable of animating selective oxidation of a myriad of alcohols by 0.67 mol% of alizarin red S anchored onto TiO2 surface under the irradiation of green light-emitting diodes. In essence, both a robust dye like ARS and anatase TiO2 with a high specific surface area hold the key to unlock the high photocatalytic activity; and superoxide is pivotal in affording the selective oxidation product. This discovery could shed light on the design of visible light photocatalysis for selective organic transformations under ambient conditions by harvesting the cooperation between an organic dye and a metal oxide.