Photocatalytic H₂ Evolution: Dealloying as Efficient Tool for the Fabrication of Rh‐decorated TiO₂ Nanotubes

Abstract

In this work, we report on a facile and novel method for decorating titanium dioxide (TiO 2 ) nanotubes with Rh nanoparticle-nanonetworks that act as co-catalysts in photocatalytic H 2 generation. In a first step, a TiÀ Rh (0.2 at%) alloy is etched in Kroll's solution leading to a dealloyed surface decorated with a Rh nanoparticle-network of adjustable geometry and loading. By subsequent anodization of the alloy samples, Rh:TiO 2 nanotubes can be grown where the tube mouths are strongly decorated with the Rh nanoparticle network (RhNw). As evident from X-ray photoelectron spectroscopy (XPS) analysis, these Rh oxide Nws are converted to metallic Rh under UV irradiation. As a result, with time a steady increase of the H 2 evolution from the RhNw decorated TiO 2 nanotubes is observed. Nanotubes carrying RhNw yield in photocatalytic experiments a 5-times higher H 2 evolution activity in comparison with nanotubes decorated by conventional Rh-sputtering (the same loading), and show a 228 times higher activity than pristine TiO 2 nanotubes.

Facile synthesis of Rh/Ti3+-TiO2 nanocomposites and its photodisinfection properties on Staphylococcus aureus under visible-NIR excitation

“…Figure 2 displays the TEM image of the Rh/Ti 3+ -TiO 2 nanocomposite. The XRD diffraction peak of Rh is clearly visible in the XRD patterns, while the signal strengthened as the atomic ratio of Rh/Ti increased [22]. Figure 2 displays the TEM image of the Rh/Ti 3+ -TiO 2 nanocomposite.…”

Reduced TiO2 nanotube array as an excellent cathode for hydrogen evolution reaction in alkaline solution

“…The TNT as cathode gave current in the range of − 0.013-0.004 mA under the bias voltage in a range from − 1.0 -0.5 V RHE . The current output of anodic TNT sample as cathode for HER is negligibly low [21]. During the LSV measurement, surface corrosion was observed in the TNT sample in the negative bias range, which is common to metal oxide cathodes [23], [28,29].…”

“…It has been intensively investigated as anode catalyst for the oxygen evolution reaction (OER) in photoelectrochemical WS cells [16][17][18][19][20]. However, the anodic TNT as HER catalyst is kinetically hampered due to the sluggish charge transfer between the semiconductor and the aqueous solution [21]. On the other hand, a monometallic Ti catalyst has a poor HER efficiency due to its large hydrogen-binding energy, i.e.…”

Constructing Rh–Rh3+ modified Ta2O5@TaON@Ta3N5 with special double n–n mutant heterojunctions for enhanced photocatalytic H2-evolution

“…In addition, Rh anchored on the surface may extract the photogenerated electrons from the VB of the Ta 3 N 5 shell layer and subsequently transfer them into the solution due to the very low overpotential. 34,37 Therefore, the superior photocatalytic H 2 evolution performance for the Rh-Ta-6 sample can be ascribed to a synergetic effect of above factors.…”