Enhanced Visible-Light Photoelectrochemical Conversion on TiO₂ Nanotubes with Bi₂S₃ Quantum Dots Obtained by in Situ Electrochemical Method

Abstract

A new greener strategy to incorporate Bi 2 S 3mercaptopropionic acid (MPA) quantum dots (QDs) onto TiO 2 nanotube (NT) films was developed, using in situ electrochemical synthesis with a graphite/sulfur powder macroelectrode (cathode) and cavity cell. Simultaneously, the obtained QDs were adsorbed on TiO 2 NTs, for the photoelectrochemical cell (PEC) assays. After the electrochemical synthesis, different thermal post-treatments were performed for growth and crystallization of obtained nanocrystals. The obtained TiO 2 −Bi 2 S 3 nanostructured composites were characterized by UV−vis, diffuse reflectance spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Photoelectrochemical tests were carried out, where TiO 2 NTs/Bi 2 S 3 QDs with 15 min post-treatment at 90 °C presented a greater photocurrent density, when irradiated with visible light (427−655 nm region, 10 mW.cm −2 ) and compared to pristine TiO 2 NTs. Such performance can be attributed to the synergetic effect caused by the good interface between TiO 2 NTs/Bi 2 S 3 QDs, promoted by the electrochemical method of synthesis employed. The proof of concept evidenced in this work can be potentially extended for the sensitization of TiO 2 NTs with other semiconductors for PEC hydrogen generation and solar cell applications.

Photocatalytic Deposition of Nanostructured CsPbBr3 Perovskite Quantum Dot Films on Mesoporous TiO2 and Their Enhanced Visible-Light Photodegradation Properties

“…HRTEM image of the TiO 2 /CsPbBr 3 particles ( Figure 6 b) shows an interplanar distance of 0.35 nm corresponding to the (101) family of planes of anatase TiO 2 . 46 …”

Indium Tin-Doped Oxide (ITO) as a High Activity Water Oxidation Photoanode

“…UV–vis spectroscopy of the slides showed the expected intense UV absorption and shift in the mid-infrared absorption following annealing above 250 °C (Figures S2–S4). Anodized titanium (Ti-TiO 2 ) electrodes were prepared according to literature procedures . Atomic layer deposition of TiO 2 was carried out on nano ITO slides annealed at 500 °C to prepare nano ITO-(TiO 2 ) n core–shell materials to assess the electrical conductivity differences between conducting and nonconducting electrodes of ITO and TiO 2 (see the Supporting Information for more details).…”

Novel Electron Donor Encapsulation Assay Based on the Split-type Photoelectrochemical Interface

“…The complex formed by encapsulating AA in MSN with CdS (CdS@MSN-AA) as a signal amplifier labeled on the anti-procalcitonin (as a sample, PCT − ) secondary antibody works as the detection antibody (CdS@MSN-AA-Ab 2 ), and the Bi 2 S 3 nanorod-sensitized porous In 2 O 3 (In 2 O 3 /Bi 2 S 3 ) works as a photosensitive substrate for providing basic PEC response. In 2 O 3 as a novel photosensitive transducer , was designed, and its band gap matched with that of Bi 2 S 3 − for offering satisfactory PEC response (Figure S1 shows the measurement of the band gap position). Meanwhile, the sandwich immunoassay was carried out in a 96-well microplate; during etching treatment with dithiothreitol (DTT), the disulfide bond between CdS and MSN was broken and the bioconjugate of CdS@MSN-AA was disintegrated, achieving the release of AA.…”