PRISTINE AND Pt-MODIFIED TiO₂ DRIVE ORGANIC COMPOUND PHOTODEGRADATION

Introduction: Sunlight-induced photocatalytic oxidation of organic matter is significant for a number of reasons, including (i) its low cost, (ii) its ability to purify air and water [1], and (iii) its role as an alternative to the selective synthesis of high-value oxygenated compounds [2].

Methods: Materials used: ethanol, TiO_2, and Pt/TiO₂ powders (obtained by sol–gel method). The reaction products of gas-phase oxidation processes were analyzed by gas-phase chromatography (GC-TCD and GC-FID).

Results: Considering light-induced ethanol oxidation on a noble metal (Pt) loaded with TiO₂, both the support and noble metals are crucial for light absorption, charge separation, and carbon dioxide generation. Platinum nanoparticles on TiO₂ can primarily cause the separation of photogenerated charges and a red shift in the light absorption edge.

Figure 1. Oxidative conversion of ethanol driven by solar light.

Conclusions: The light-initiated photo-oxidative routes ofan organic substrate over TiO₂ charged with noble metals are revealed in this study. The production of carbon dioxide, the separation of the light-generated charges by platinum addition, and the mechanism of the oxidative conversion reaction of ethanol are the main topics of this analysis of the intricate phenomena connected to the photocatalytic processes.

References:

• Paz, Application of TiO₂ photocatalysis for air treatment: Patents overview, Appl. Catal. B 2010, 99, 448-460.
• Kou et all, Selectivity enhancement in heterogeneous photocatalytic transformation, Chem. Rev. 2017, 117, 1445-1514.