Pt-doped TiO2 nanotubes as photocatalysts and electrocatalysts for enhanced photocatalytic H2 generation, electrochemical sensing, and supercapacitor applications

Synthesis and Characterization of Iron-Doped TiO2 Nanotubes (Fe/TiNTs) with Photocatalytic Activity

“…Their product exhibits a remarkably high photocatalytic capacity to evolve hydrogen, to an extent of 850 mmol/5 mg within 40 min. Next to these examples, a large number of other publications have published on the doping of TiO 2 nanoparticles [9][10][11][12][13][14][15][16][17][18][19][20].…”

CO2 Photoreduction Activity Enhancement and Unexpected Observation of Carbon Monoxide Adsorbates on the Surface of TiO2 Nanotube Arrays Synthesized in Formamide Electrolytes

“…The highly ordered and vertically aligned nanotube array architecture is therefore ideally suited for a range of optoelectronic device applications including, but not limited to, photocatalysts, photoelectrochemical cells, photodetectors, electron transport layers for organic- and perovskite solar cells, all-dielectric and hyperbolic metamaterials, photonic crystals, chemiresistive gas sensors, label-based fluorescence biosensors, and label-free refractive index sensors (see the Supporting Information for comprehensive list of references related to optoelectronic device applications). Among the various anodically formed metal oxide nanomaterials, TiO 2 nanotube arrays (TNTAs) composed of a dominant anatase phase have shown the most promise in catalytic applications such as CO 2 photoreduction, − photoelectrochemical water splitting, − photocatalytic hydrogen production, − and sunlight-assisted wastewater treatment. − In the overwhelming majority of these studies, TNTAs are synthesized through anodization in ethylene glycol (EG)-based electrolytes containing water and fluoride salt(s). TNTAs grown in EG-based electrolytes (TNTA-EG) have a honeycomb-like structure with the nanopores organized in a triangular lattice with very smooth sidewalls, an architecture that results in a suboptimal specific surface area for catalysis. , The defect structure in TNTA-EG has been extensively studied and is known to consist of oxygen vacancies, Ti 3+ states, and surface and subsurface hydroxyl groups. , The resulting trap states are of two kinds, a broad distribution of shallow traps (∼0.1 eV below E c ) and deep-level trapping centers for both electrons (∼1–1.4 eV below E c ) and holes (∼1–1.2 eV above E v ). − While traps are uniformly negative for photovoltaics, they can also serve a positive function in photodetectors and photocatalysts, for instance as a source of photoconductive gain and as a facilitator of direct charge transfer to chemisorbed reactant molecules. − …”