Establishing High Photocatalytic H2 Evolution from Multiwalled Titanate Nanotubes

• Published in: ChemCatChem Vol. 12; no. 11; pp. 2951 - 2956
• Main Authors: Yoo, Jeong Eun, Alshehri, Abdulmohsen Ali, Qin, Shanshan, Bawaked, Salem Mohamed, Mostafa, Mohamed Mokhtar M., Katabathini, Narasimharao, Fehn, Dominik, Schmidt, Jochen, Mazare, Anca, Denisov, Nikita, Cha, Gihoon, Meyer, Karsten, Schmuki, Patrik
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 05.06.2020
• Subjects: absorption; Anatase; Blackening; Catalytic activity; hydrogen evolution; Hydrogen production; hydrogenation; hydrothermal titania nanotubes; Morphology; Nanotubes; Noble metals; Photocatalysis; Titanium dioxide; Water splitting
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.202000281

Black TiO2 in various forms has been investigated for numerous photochemical applications. In photocatalytic water splitting, “grey” titania forms have been reported to reach considerable H2 generation rates without using a noble metal co‐catalyst. Up to now, a variety of anatase powders or other morphologies has been investigated in grey and black forms. Here we describe that hydrothermal titanate/anatase nanotubes can show a strong noble metal free photocatalytic activity. For optimized “blackening” conditions, a drastically higher photocatalytic H2 production can be obtained than for other nanoscale morphologies. This effect can further be improved with a very mild Pt doping that again shows a clearly stronger photocatalytic H2 production than comparably loaded nanopowders. Hydrothermal titania nanotubes: Powders of ‘black’ titanate/anatase nanotubes were prepared by hydrothermal synthesis followed by an annealing at various temperatures in H2 atmosphere. The optimized ‘grey’ powder shows a much higher photocatalytic activity for H2 production than other TiO2 nanoscale morphologies. This holds for samples with and without noble metal doping.