Operando Laboratory X-ray Absorption Spectroscopy and UV–Vis Study of Pt/TiO[sub.2] Photocatalysts during Photodeposition and Hydrogen Evolution Reactions

• Published in: Catalysts Vol. 13; no. 2
• Main Authors: Kozyr, Elizaveta G, Njoroge, Peter N, Chapek, Sergei V, Shapovalov, Viktor V, Skorynina, Alina A, Pnevskaya, Anna Yu, Bulgakov, Alexey N, Soldatov, Alexander V, Pellegrino, Francesco, Groppo, Elena, Bordiga, Silvia, Mino, Lorenzo, Bugaev, Aram L
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.02.2023
• Subjects: Hydrogen; Radiation; Spectrum analysis; Japan
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal13020414

Photocatalytic hydrogen (H[sub.2]) production is a promising route for alternative energetics. Understanding structure-activity relationships is a crucial step towards the rational design of photocatalysts, which requires the application of operando spectroscopy under relevant working conditions. We performed an operando investigation on a catalytic system during the photodeposition of Pt on TiO[sub.2] and photostimulated H[sub.2] production, using simultaneous laboratory X-ray absorption spectroscopy (XAS), UV-Vis spectroscopy, and mass spectrometry. XAS showed a progressive increase in Pt fluorescence for Pt deposited on TiO[sub.2] for over an hour, which is correlated with the signal of the produced H[sub.2]. The final Pt/TiO[sub.2] catalyst contained Pt(0) particles. The electronic features corresponding to the Pt[sup.4+] species in the UV-Vis spectrum of the solution disappear as soon as UV radiation is applied in the presence of formic acid, which acts as a hole scavenger, resulting in the presence of Pt(0) particles in solution.